Welcome, Guest. Please Login or Register
Decware Audio Forums
05/25/20 at 02:59:07 


       


10% off your entire order until June 1st! Use coupon code: COVID19

Pages: 1 ... 8 9 10 11 12 ... 15
Send Topic Print
Anyone Tube Roll with the ZMA yet? (Read 200947 times)
stone_of_tone
Seasoned Member
****


Listen Often/Listen
Deep

Posts: 3217
Re: Anyone Tube Roll with the ZMA yet?
Reply #450 - 08/04/18 at 15:49:21
 
"So for now I just want to listen..."

Same here, Norm....holding off on either getting the KT77 Gold Lion's or Tung-Sol 7027A's, until October.

...till then, Enjoy.



Buying some Music, the next couple of months!

Plenty of tube rolling enjoyment to be had, below........for the next 8 weeks.

Constants:
NOS/Platinum/Telefunken E88CC for Inverter Tubes
NOS RCA 0A3's.

Rotation:
Matched Quad/Tung-Sol Cryo'd 7581A's
Reflector Cryo'd 6P's
Gold Lion KT88's Cryo'd.

Rotation:
~NOS Platinum Tubes from Upscale Audio~

(Great Britain) Mullard 7308/E188CC ~  2 pair (both pair Cryogenic)
(Germany) Telefunken 6922/E88CC ~ 1 pair (painfully expensive/worth it)
(US/Great Britain) Ediswan CV2492/6922 ~ 2 pair (one pair Cryogenic)
(Hungary) Tungsram 6922/E88CC ~ 1 pair
(Hungary) Tungsram PCC88/7DJ8 ~ 1 pair.
Back to top
 
 

Room Treats-M.Green & mine
Sony TPort
Illuminati D60
Shunyata Z-Alpha DigPcord
Decware ZDSD DAC
Kimber Select KS1030
XLOProPcord
Decware ZMA/25th Mods
Kimber Select KS6063
Acoustic Zen Adagio/Modified
Kimber PK10 Palladian from wall
to PS Audio P3
  IP Logged
Archie
Seasoned Member
****




Posts: 1882
Re: Anyone Tube Roll with the ZMA yet?
Reply #451 - 08/04/18 at 17:57:06
 
My 7581As are settling in nicely.  I am biasing at 52mA for no particular reason other than that's what I bias the 6Ps.  I think I'm getting more headroom as these break in.  Detail is fantastic and the tonal balance is great to my ears.

Thanks Stone for pioneering these tubes!   Smiley
Back to top
 
 

Technics 1200G TT w/ Ortofon Jubilee MC cart
ZMC1
ZP3 (25th A Mods)
ZR2 (25th A Mods)
CSP3 (25th A mods)
ZMA (25th A mods)
ZLC
Homemade Big Betsy Speakers
Silver Cabling
DIY Isolation platforms under amps & TT.
  IP Logged
stone_of_tone
Seasoned Member
****


Listen Often/Listen
Deep

Posts: 3217
Re: Anyone Tube Roll with the ZMA yet?
Reply #452 - 08/04/18 at 20:47:26
 
You bet Archie.

I am enthralled by these 7581A's.

As you stated: The headroom, detail & tonal balance is impressive.

The Dynamic headroom I'm getting with so much clarity of tone on this rain filled Saturday afternoon ..... I'm so pleased... .

Have a great rest of your weekend!

PS~even though we all should take reviews with a grain of salt....I like what I'm reading about the GL KT77's.....they could be October's buy...from Ron.
https://www.upscaleaudio.com/products/gold-lion-kt77-el34#shopify-product-review...
Back to top
 
 

Room Treats-M.Green & mine
Sony TPort
Illuminati D60
Shunyata Z-Alpha DigPcord
Decware ZDSD DAC
Kimber Select KS1030
XLOProPcord
Decware ZMA/25th Mods
Kimber Select KS6063
Acoustic Zen Adagio/Modified
Kimber PK10 Palladian from wall
to PS Audio P3
  IP Logged
stone_of_tone
Seasoned Member
****


Listen Often/Listen
Deep

Posts: 3217
Re: Anyone Tube Roll with the ZMA yet?
Reply #453 - 08/11/18 at 14:45:48
 
Enjoying this morning, these Tung-Sol 7581A's. I am in no hurry to tube roll my Reflec 6P's or GL KT88's back in......and those quads are stellar also!

Running my Ediswan CV2492/6922 pair for inputs & Telefunken 6922/E88CC for inverter's.....absolutely stunning with these 7581A's.



....holding off on getting the KT77 Gold Lion's & Tung-Sol 7027A's, until October (I plan on getting both, then).

RFT EL34's...still on my radar & Psvane EL34's too.
Back to top
 
 

Room Treats-M.Green & mine
Sony TPort
Illuminati D60
Shunyata Z-Alpha DigPcord
Decware ZDSD DAC
Kimber Select KS1030
XLOProPcord
Decware ZMA/25th Mods
Kimber Select KS6063
Acoustic Zen Adagio/Modified
Kimber PK10 Palladian from wall
to PS Audio P3
  IP Logged
Archie
Seasoned Member
****




Posts: 1882
Re: Anyone Tube Roll with the ZMA yet?
Reply #454 - 08/11/18 at 17:26:02
 
Stone, is it my imagination or does headroom improve as these tubes break in?  I'm with you 100% and I think my next tube buy will be another quad of 7581As!
Back to top
 
 

Technics 1200G TT w/ Ortofon Jubilee MC cart
ZMC1
ZP3 (25th A Mods)
ZR2 (25th A Mods)
CSP3 (25th A mods)
ZMA (25th A mods)
ZLC
Homemade Big Betsy Speakers
Silver Cabling
DIY Isolation platforms under amps & TT.
  IP Logged
stone_of_tone
Seasoned Member
****


Listen Often/Listen
Deep

Posts: 3217
Re: Anyone Tube Roll with the ZMA yet?
Reply #455 - 08/11/18 at 17:43:01
 
It is not your imagination Archie. I'm still in my Listening Room at 11:40 am here (I came in here at 6:25 am). My girl friend is going to be mad when she gets back that I have not shaved and showered to go yet!

These tubes/headroom are blowing my mind! No hyperbole, just joy!


PS ~ she loves music - but, down on the other Rig with my Debut Carbon TT. Her nephew transferred to the U of M.... He loves Vinyl and will be stopping by time to time, to get fed and nourish his soul from the big Polk 1.2's.....!   Eventually, I will see if he can wrap his brain around the ZMA. Some, can only stay in the Debut Carbon Polk 1.2 zone though. Which is okay....as long as they love music.
Back to top
 
 

Room Treats-M.Green & mine
Sony TPort
Illuminati D60
Shunyata Z-Alpha DigPcord
Decware ZDSD DAC
Kimber Select KS1030
XLOProPcord
Decware ZMA/25th Mods
Kimber Select KS6063
Acoustic Zen Adagio/Modified
Kimber PK10 Palladian from wall
to PS Audio P3
  IP Logged
NormD
Seasoned Member
****




Posts: 199
Re: Anyone Tube Roll with the ZMA yet?
Reply #456 - 08/12/18 at 03:27:18
 
I’m on the same camp. I bought a second quad of the Tung Sol 7581’s as backup.  Not changing them any time soon.
Back to top
 
 

OPPO Sonica DAC
Technics SL-1200M3D Turntable
SoundSmith The Voice cartridge
JRMedia Center running on a MacMini
Oppo 103D for video
Marantz AV8802a Pre
ZTPre & ZMA for Stereo
Rotel RMB-1585 amp
Focal Electra 1038Be speakers (93 db)
2Hsu Research ULS-15 M
  IP Logged
stone_of_tone
Seasoned Member
****


Listen Often/Listen
Deep

Posts: 3217
Re: Anyone Tube Roll with the ZMA yet?
Reply #457 - 08/14/18 at 20:48:33
 
Ditto Norm & Arch.

I have a further note of appreciation of this tube quad?! I can Bias them between 45 mA & 58 mA....to great sonic's!!!!

45 mA for moderate to low level Listening with revealing no etch detail = I dare say Triode.....(not dare say - I am saying it).

However, at 58 mA.....I can really push the SPL's if wanted...and obtain beauty in power....of maintained tonal balance with goose bumps!

ONLY ON A ZMA ....with Balance adjustment to boot!

Yes, I was able to have the JOY of my ZMA today................ .
Back to top
 
 

Room Treats-M.Green & mine
Sony TPort
Illuminati D60
Shunyata Z-Alpha DigPcord
Decware ZDSD DAC
Kimber Select KS1030
XLOProPcord
Decware ZMA/25th Mods
Kimber Select KS6063
Acoustic Zen Adagio/Modified
Kimber PK10 Palladian from wall
to PS Audio P3
  IP Logged
stone_of_tone
Seasoned Member
****


Listen Often/Listen
Deep

Posts: 3217
Re: Anyone Tube Roll with the ZMA yet?
Reply #458 - 08/21/18 at 22:01:13
 
Okay, I know I said I was going to spring for both quads at once. However, I only want to bring in one quad at a time, as I have done with the other quads (...and I'm NOT waiting till October....cause I'm keeping my ZMA pure for now).

.......should I get the Gold Lion KT77's or Tung-Sol 7027A's next? Believe me, I could keep the T-Sol 7581A's in indefinitely ......but, Rolin' is about rollin'!

What should I get?



Constants:
NOS/Platinum/Telefunken 6922/E88CC for Inverter Tubes (yes/the painfully expensive ones, from Upscale Audio = worth it, yes)
NOS RCA 0A3's.

Rotation/Power Quads:
~Matched Quad's~

Tung-Sol Cryo'd 7581A's
Reflector Cryo'd 6P's
Gold Lion KT88's Cryo'd
PENDING PURCHASE ~ GL KT77'S or T-Sol 7027A's.


Rotation/Input Tubes:
~NOS Platinum Tubes from Upscale Audio~

(Great Britain) Mullard 7308/E188CC ~  2 pair (both pair Cryogenic)
(US/Great Britain) Ediswan CV2492/6922 ~ 2 pair (one pair Cryogenic)
(Hungary) Tungsram 6922/E88CC ~ 1 pair
(Hungary) Tungsram PCC88/7DJ8 ~ 1 pair

~Control/came with ZMA~
(Russia) 6N23P ~ 2 pair.
Back to top
 
 

Room Treats-M.Green & mine
Sony TPort
Illuminati D60
Shunyata Z-Alpha DigPcord
Decware ZDSD DAC
Kimber Select KS1030
XLOProPcord
Decware ZMA/25th Mods
Kimber Select KS6063
Acoustic Zen Adagio/Modified
Kimber PK10 Palladian from wall
to PS Audio P3
  IP Logged
Jeff of Arabica
Seasoned Member
****


Name the greatest of
all inventors...
Accident.

Posts: 916
Re: Anyone Tube Roll with the ZMA yet?
Reply #459 - 08/21/18 at 23:19:22
 
I am casting my vote for the T.S. 7027A’s.  Plate dissipation is 35W vs. 25W on the KT77’s.  What I am finding is the ZMA responds better to tubes that can handle a higher bias, which a higher plate dissipation rating will allow.   You can bias the 7027A’s at 60-64mA based on the plate voltage of 390V on the ZMA, which puts them at the 68-70% range of max on these tubes - a very safe and prudent range to operate tubes when longevity is also desired.  Safe, but not boring.  I have my 7027A’s in now at 64mA and they are crankin’ both in overall output AND dynamics/mids/treble sparkle.  

As a matter of fact, I was originally running these tubes at 60mA, but then I measured the plate voltage at the tube socket and realized I could safely bump it to 64mA without overly stressing the tube or overheating the power transformers.
Back to top
 
 

Canary Audio Grand Reference//ZMA//Zen Ultra//Taboo MKIII//PS Audio DirectStream DAC + Memory Player + P10//Canary Audio MC-10 Phono Stage//London Decca Reference//Dynavector DV-507 MKII//SonoruS Reel-to-Reel w/ tube playback pre-amp//Tannoy Westminster Speakers
  IP Logged
Archie
Seasoned Member
****




Posts: 1882
Re: Anyone Tube Roll with the ZMA yet?
Reply #460 - 08/21/18 at 23:53:33
 
Jeff, what is the bias window for those tubes?  Since I don't have a way to measure plate dissipation I'm looking for an idea of where you ended up in the overall range.
Back to top
 
 

Technics 1200G TT w/ Ortofon Jubilee MC cart
ZMC1
ZP3 (25th A Mods)
ZR2 (25th A Mods)
CSP3 (25th A mods)
ZMA (25th A mods)
ZLC
Homemade Big Betsy Speakers
Silver Cabling
DIY Isolation platforms under amps & TT.
  IP Logged
Jeff of Arabica
Seasoned Member
****


Name the greatest of
all inventors...
Accident.

Posts: 916
Re: Anyone Tube Roll with the ZMA yet?
Reply #461 - 08/22/18 at 01:16:13
 
Archie,
You can find the specifications of any tube type on the internet, but attached here is a list of the most common tubes and their respective plate dissipation ratings.

I was going to post on this in the general forum as I feel it could be useful to any Decware user.  

For the ZMA with a 35W tube, 70% of maximum is about 64mA on the bias.  That is where I set my 7027A's.  And as I mentioned earlier, using this method allowed me to comfortably raise the bias from 60mA where I had it prior, to 64mA.   Some believe even going as high as 75% of the tube's maximum is within reason.  That would bump the bias to 68mA.  

Back to top
 
 

Canary Audio Grand Reference//ZMA//Zen Ultra//Taboo MKIII//PS Audio DirectStream DAC + Memory Player + P10//Canary Audio MC-10 Phono Stage//London Decca Reference//Dynavector DV-507 MKII//SonoruS Reel-to-Reel w/ tube playback pre-amp//Tannoy Westminster Speakers
  IP Logged
Archie
Seasoned Member
****




Posts: 1882
Re: Anyone Tube Roll with the ZMA yet?
Reply #462 - 08/22/18 at 02:10:12
 
So, if I understand correctly, if my bias window was 40mA to 60mA, I might want to bias around 55mA?  Or doesn't it work this way?
Back to top
 
 

Technics 1200G TT w/ Ortofon Jubilee MC cart
ZMC1
ZP3 (25th A Mods)
ZR2 (25th A Mods)
CSP3 (25th A mods)
ZMA (25th A mods)
ZLC
Homemade Big Betsy Speakers
Silver Cabling
DIY Isolation platforms under amps & TT.
  IP Logged
Jeff of Arabica
Seasoned Member
****


Name the greatest of
all inventors...
Accident.

Posts: 916
Re: Anyone Tube Roll with the ZMA yet?
Reply #463 - 08/22/18 at 02:35:10
 
It depends on the tube of course, and your preference for sound, but if wanting to push it as far as you can for greatest dynamics/output for instance, while reducing the chance of premature failure, you would run them at 70% of their maximum.  A 35W tube on an amp with a plate voltage of 390 volts (ZMA), would yield a bias rating of about 63mA.  100% (maximum current) would be about 90mA.  So technically, the window would extend to 90mA (the tubes maximum rating based on the ZMA’s plate voltage), but of course you would not want to bias up to that point for tube and ZMA health reasons.
Back to top
 
 

Canary Audio Grand Reference//ZMA//Zen Ultra//Taboo MKIII//PS Audio DirectStream DAC + Memory Player + P10//Canary Audio MC-10 Phono Stage//London Decca Reference//Dynavector DV-507 MKII//SonoruS Reel-to-Reel w/ tube playback pre-amp//Tannoy Westminster Speakers
  IP Logged
Archie
Seasoned Member
****




Posts: 1882
Re: Anyone Tube Roll with the ZMA yet?
Reply #464 - 08/22/18 at 15:56:48
 
I read your excellent biasing post in the other thread.  I doubt that I'll get that technical so I was wondering it there was a shortcut to the approximate end of 70% to 75% but I'm guessing the bias window and the % is not linear.  (Up till now, I use relatively cheap tubes so it's not a huge concern.)
Back to top
 
 

Technics 1200G TT w/ Ortofon Jubilee MC cart
ZMC1
ZP3 (25th A Mods)
ZR2 (25th A Mods)
CSP3 (25th A mods)
ZMA (25th A mods)
ZLC
Homemade Big Betsy Speakers
Silver Cabling
DIY Isolation platforms under amps & TT.
  IP Logged
Jeff of Arabica
Seasoned Member
****


Name the greatest of
all inventors...
Accident.

Posts: 916
Re: Anyone Tube Roll with the ZMA yet?
Reply #465 - 08/23/18 at 17:08:58
 
The plate voltages across all ZMA’s should be consistent as long as the amp has not been modified with parts outside of the original specifications,  leading up to the output tubes cathode.  

So, you can use 386 volts in your calculations.  If using a KT66 (25W), you would then run the calculation,  25/386 X .7 = 45mA.   That would be if you biased it at 70% of maximum.  You can certainly go higher and not run the risk of damaging the amp, but then you are running the tubes harder and likely reducing its lifespan.  But if your tubes are available and cheap, that should not matter.  If you ran them at 75%, the bias setting would be 49mA.   In the ZMA, with its plate volatage, running the KT66 tubes at their maximum allowable current (100%), the bias setting would be 65mA.  

This methodology brings clarity to how light or hard you are running your tubes.  This will help you push harder, or pull back, when taking into consideration the bias range and impact on lifespan for a particular tube type.  The rest is up to your ears as to what sounds best in your amp, in your system.  With my 7027A’s, which are super expensive, using this methods I was actually able to comfortably push the bias up another 4mA, which I preferred over the 60mA setting I was using prior.
Back to top
 
 

Canary Audio Grand Reference//ZMA//Zen Ultra//Taboo MKIII//PS Audio DirectStream DAC + Memory Player + P10//Canary Audio MC-10 Phono Stage//London Decca Reference//Dynavector DV-507 MKII//SonoruS Reel-to-Reel w/ tube playback pre-amp//Tannoy Westminster Speakers
  IP Logged
Archie
Seasoned Member
****




Posts: 1882
Re: Anyone Tube Roll with the ZMA yet?
Reply #466 - 08/23/18 at 17:17:19
 
Simple, thanks!
Back to top
 
 

Technics 1200G TT w/ Ortofon Jubilee MC cart
ZMC1
ZP3 (25th A Mods)
ZR2 (25th A Mods)
CSP3 (25th A mods)
ZMA (25th A mods)
ZLC
Homemade Big Betsy Speakers
Silver Cabling
DIY Isolation platforms under amps & TT.
  IP Logged
Archie
Seasoned Member
****




Posts: 1882
Re: Anyone Tube Roll with the ZMA yet?
Reply #467 - 08/23/18 at 17:24:05
 
I've been running my Tung Sol 7851As (35W PD) at 52mA which by that calculation is very low.  I'm not sure they will bias up to the 70% or 75% level but when I get my ZMA back from Steve I'll have to play around with this.

Stone, how high can you bias your 7851As?
Back to top
 
 

Technics 1200G TT w/ Ortofon Jubilee MC cart
ZMC1
ZP3 (25th A Mods)
ZR2 (25th A Mods)
CSP3 (25th A mods)
ZMA (25th A mods)
ZLC
Homemade Big Betsy Speakers
Silver Cabling
DIY Isolation platforms under amps & TT.
  IP Logged
Archie
Seasoned Member
****




Posts: 1882
Re: Anyone Tube Roll with the ZMA yet?
Reply #468 - 08/23/18 at 17:36:59
 
Jeff, do you know the plate dissipation of the 6P3S-E tubes?  I haven't had any luck finding it.  I bias those around 52mA too which I recall is near the high end of what the ZMA will bias those.
Back to top
 
 

Technics 1200G TT w/ Ortofon Jubilee MC cart
ZMC1
ZP3 (25th A Mods)
ZR2 (25th A Mods)
CSP3 (25th A mods)
ZMA (25th A mods)
ZLC
Homemade Big Betsy Speakers
Silver Cabling
DIY Isolation platforms under amps & TT.
  IP Logged
Jeff of Arabica
Seasoned Member
****


Name the greatest of
all inventors...
Accident.

Posts: 916
Re: Anyone Tube Roll with the ZMA yet?
Reply #469 - 08/23/18 at 19:45:20
 
Archie,
They are the same as 6L6GC’s, so 30W (edited) plate dissipation.  
Back to top
 
 

Canary Audio Grand Reference//ZMA//Zen Ultra//Taboo MKIII//PS Audio DirectStream DAC + Memory Player + P10//Canary Audio MC-10 Phono Stage//London Decca Reference//Dynavector DV-507 MKII//SonoruS Reel-to-Reel w/ tube playback pre-amp//Tannoy Westminster Speakers
  IP Logged
stone_of_tone
Seasoned Member
****


Listen Often/Listen
Deep

Posts: 3217
Re: Anyone Tube Roll with the ZMA yet?
Reply #470 - 08/23/18 at 22:12:48
 
Cool Jeff, I will have to plug my dissapations into your formula.

Yes, ...the 7027A's... . I will get them soon.

The 7581A's can bias from 42 up to 64 mA.....incredible
Quad of tubes! I run them at 50 mostly....but sometimes hammer on them at 60. Plus, I esoteric run them at 45....pretty impressive at lower vol...for the 45.

But love my 6P's too at 48 to 52 bias and my mighty Gold Lion Cryo'd KT88's..I run at 72 instead of 78 for obvious reasons/6 hour session max on my 88's.
Back to top
 
 

Room Treats-M.Green & mine
Sony TPort
Illuminati D60
Shunyata Z-Alpha DigPcord
Decware ZDSD DAC
Kimber Select KS1030
XLOProPcord
Decware ZMA/25th Mods
Kimber Select KS6063
Acoustic Zen Adagio/Modified
Kimber PK10 Palladian from wall
to PS Audio P3
  IP Logged
Archie
Seasoned Member
****




Posts: 1882
Re: Anyone Tube Roll with the ZMA yet?
Reply #471 - 08/24/18 at 00:37:59
 
So, it looks like I run my 6Ps (although I'm seeing 30W for the 6L6GCs) on the high side and at 70% the 7851As would bias at the top of their limit in the ZMA.  I'll push mine higher than the 52mA I've been running.

I found this site which Seems pretty close to the same calc base on AB and a voltage of 400V.  Steve lists the ZMA as 410VDC if I read the specs right.

http://www.tedweber.com/webervst/tubes1/calcbias.htm
Back to top
 
 

Technics 1200G TT w/ Ortofon Jubilee MC cart
ZMC1
ZP3 (25th A Mods)
ZR2 (25th A Mods)
CSP3 (25th A mods)
ZMA (25th A mods)
ZLC
Homemade Big Betsy Speakers
Silver Cabling
DIY Isolation platforms under amps & TT.
  IP Logged
Jeff of Arabica
Seasoned Member
****


Name the greatest of
all inventors...
Accident.

Posts: 916
Re: Anyone Tube Roll with the ZMA yet?
Reply #472 - 08/24/18 at 02:13:27
 
Archie,
You are correct, 6L6GC tubes have a 30W plate dissipation, not 25W.  That being said, it changes the 70% to 54mA and 75% to 58mA.

The only true way to know the plate voltage is to measure it directly at the tube socket, using a meter.  That being said, when I measured the plate voltages on my ZMA, I have gotten readings between 386-390 volts consistently.  But you can expect a few volts variation and that is fine.  For the purposes of getting in range, no need to go out of your way to take a reading on your ZMA as you will be close enough to the range that I measured.  And this isn't meant to be an exact science or to take the place of dialing in by listening.  But, it is a great tool to help understand the operating ranges of the tubes you own based on the operating environment of your amp.  This information is especially handy when you want to explore the "hotter" bias ranges without running them reckless.    

Yeah, the chart and calculator on that site is based on the same formula.  
Back to top
 
 

Canary Audio Grand Reference//ZMA//Zen Ultra//Taboo MKIII//PS Audio DirectStream DAC + Memory Player + P10//Canary Audio MC-10 Phono Stage//London Decca Reference//Dynavector DV-507 MKII//SonoruS Reel-to-Reel w/ tube playback pre-amp//Tannoy Westminster Speakers
  IP Logged
Archie
Seasoned Member
****




Posts: 1882
Re: Anyone Tube Roll with the ZMA yet?
Reply #473 - 08/24/18 at 15:56:59
 
This question of bias for a given tube has come up for years and I want to thank you for finally putting some sense to it.  Do you know if the 410VDC that Steve mentions in the ZMA specs list on the ZMA web page relates to the 386V to 390V that you measure?
Back to top
 
 

Technics 1200G TT w/ Ortofon Jubilee MC cart
ZMC1
ZP3 (25th A Mods)
ZR2 (25th A Mods)
CSP3 (25th A mods)
ZMA (25th A mods)
ZLC
Homemade Big Betsy Speakers
Silver Cabling
DIY Isolation platforms under amps & TT.
  IP Logged
Jeff of Arabica
Seasoned Member
****


Name the greatest of
all inventors...
Accident.

Posts: 916
Re: Anyone Tube Roll with the ZMA yet?
Reply #474 - 08/24/18 at 16:59:40
 
Quote:
Do you know if the 410VDC that Steve mentions in the ZMA specs list on the ZMA web page relates to the 386V to 390V that you measure?


Archie, that is a great question and maybe Steve will see this and provide a definitive answer.  My assumption is the 410 volts is purely based on the specs of the parts in the power supply chain - what they should amount to in theory.  The 386-390 volts is reality, what it actually measures.  All electronics parts have a tolerance - some tighter than others.  These tolerances will by nature create variances which are normal and fine.  When they start to drift too far out of spec is when things start to get wonky and replacement of said part(s) becomes necessary.  

For the purpose of this biasing exercise, what measures at the cathode of the output tubes is what matters, but really, since this is a guideline to follow, the difference between 390 to 410 volts amounts to maybe one or two mA difference.  You could split the difference and assume 400 volts and be perfectly fine.
Back to top
 
 

Canary Audio Grand Reference//ZMA//Zen Ultra//Taboo MKIII//PS Audio DirectStream DAC + Memory Player + P10//Canary Audio MC-10 Phono Stage//London Decca Reference//Dynavector DV-507 MKII//SonoruS Reel-to-Reel w/ tube playback pre-amp//Tannoy Westminster Speakers
  IP Logged
stone_of_tone
Seasoned Member
****


Listen Often/Listen
Deep

Posts: 3217
Re: Anyone Tube Roll with the ZMA yet?
Reply #475 - 08/25/18 at 17:12:04
 
I have the 6P's in and find them lush compared to the 7581A's. Not overly so....beautiful detail coming from an black velvet background...so the 6P's will always have their lane/place in my ZMA.

Love the distinct differences of my KT88's, 6P's & 7581A's. I hope to go 4 for 4 with the 7027A's!
Back to top
 
 

Room Treats-M.Green & mine
Sony TPort
Illuminati D60
Shunyata Z-Alpha DigPcord
Decware ZDSD DAC
Kimber Select KS1030
XLOProPcord
Decware ZMA/25th Mods
Kimber Select KS6063
Acoustic Zen Adagio/Modified
Kimber PK10 Palladian from wall
to PS Audio P3
  IP Logged
stone_of_tone
Seasoned Member
****


Listen Often/Listen
Deep

Posts: 3217
Re: Anyone Tube Roll with the ZMA yet?
Reply #476 - 08/25/18 at 17:35:39
 
....and decay end trails from the 6P's are goosebumps with a Cheshire Cat smile.

Another session where I have to carve myself away from my Decware, to move on with my Saturday here....!!
I will be almost glad when it's 10 below again and having absolutely no reason to head out on the weekend!
Back to top
 
 

Room Treats-M.Green & mine
Sony TPort
Illuminati D60
Shunyata Z-Alpha DigPcord
Decware ZDSD DAC
Kimber Select KS1030
XLOProPcord
Decware ZMA/25th Mods
Kimber Select KS6063
Acoustic Zen Adagio/Modified
Kimber PK10 Palladian from wall
to PS Audio P3
  IP Logged
stone_of_tone
Seasoned Member
****


Listen Often/Listen
Deep

Posts: 3217
Re: Anyone Tube Roll with the ZMA yet?
Reply #477 - 08/26/18 at 18:45:01
 
.....but as sweet as the 6P's are....I thought they would only last a day by comparison... .

....the 7581A's are back in. Oh boy, the Power is effortless and the grace of these...wow. Nough said.
Back to top
 
 

Room Treats-M.Green & mine
Sony TPort
Illuminati D60
Shunyata Z-Alpha DigPcord
Decware ZDSD DAC
Kimber Select KS1030
XLOProPcord
Decware ZMA/25th Mods
Kimber Select KS6063
Acoustic Zen Adagio/Modified
Kimber PK10 Palladian from wall
to PS Audio P3
  IP Logged
stone_of_tone
Seasoned Member
****


Listen Often/Listen
Deep

Posts: 3217
Re: Anyone Tube Roll with the ZMA yet?
Reply #478 - 08/26/18 at 19:04:32
 
The bump up to the 35 watt plate dissipation in the T-Sol 7581A's, is so evident...it is not even funny.
...and how they destroy the T-Sol KT66... Is a thing to the ear to behold.

The brother of these guys at 35 WPD....7027A's......need to come in...but holding off for now.... These freakin 7581A's need to run a long time first!

This is not to say the sweet 23 WPD 6P's and the 25 WPD KT66's don't stay in the rotation, cause they will. Just that the 7581A's, after almost two months with them, will see more playing time...they are that good. The different animal, KT88's 35 WPD ...will of course see its safe fair share of play time too.

So, I have to complete the trifecta 35 WPD, with the T-Sol 7027A's.

Preferring my NOS PLAT gold pin Ediswan's for inputs over my NOS PLAT gold pin Mullard's with these 7581A's. I do need to try my couple of Tungsram's with them and the classic 6N23P's too. My constant is the NOS PLAT gold pin Telefunken for inverter's and NOS RCA 0A3's.
Back to top
 
 

Room Treats-M.Green & mine
Sony TPort
Illuminati D60
Shunyata Z-Alpha DigPcord
Decware ZDSD DAC
Kimber Select KS1030
XLOProPcord
Decware ZMA/25th Mods
Kimber Select KS6063
Acoustic Zen Adagio/Modified
Kimber PK10 Palladian from wall
to PS Audio P3
  IP Logged
stone_of_tone
Seasoned Member
****


Listen Often/Listen
Deep

Posts: 3217
Re: Anyone Tube Roll with the ZMA yet?
Reply #479 - 08/30/18 at 22:20:10
 
Four day weekend begins NOW! Happy Labor Day weekend to all.

Well, I have to move my youngest into her Freshman Dorm tomorrow and then I have a new Oven coming in the afternoon at home. My aching back.

Saturday night I get to roll a couple pair of input NOS Tubes with the 7581A's. I look forward to that ....Cheers!

PS - Arch, you get your ZMA back yet?
Back to top
 
 

Room Treats-M.Green & mine
Sony TPort
Illuminati D60
Shunyata Z-Alpha DigPcord
Decware ZDSD DAC
Kimber Select KS1030
XLOProPcord
Decware ZMA/25th Mods
Kimber Select KS6063
Acoustic Zen Adagio/Modified
Kimber PK10 Palladian from wall
to PS Audio P3
  IP Logged
NormD
Seasoned Member
****




Posts: 199
Re: Anyone Tube Roll with the ZMA yet?
Reply #480 - 08/30/18 at 23:37:10
 
I just ordered a pair of JJ 7027a's and the spec sheet says 30W, so by my calculations that is 54ma at 70%.  My TS 7581a's are rated at 35w and I'm running them at 50ma, but by your calculations, I could bump them up to 63ma or so.  Did I get that right?  Question is, should I bump them up?

If I want two measure the B+ (plate) voltage on my amp, can I simply pull a tube up a bit and measure pin 3? Any suggestions on where to clip my ground?
Back to top
 
 

OPPO Sonica DAC
Technics SL-1200M3D Turntable
SoundSmith The Voice cartridge
JRMedia Center running on a MacMini
Oppo 103D for video
Marantz AV8802a Pre
ZTPre & ZMA for Stereo
Rotel RMB-1585 amp
Focal Electra 1038Be speakers (93 db)
2Hsu Research ULS-15 M
  IP Logged
stone_of_tone
Seasoned Member
****


Listen Often/Listen
Deep

Posts: 3217
Re: Anyone Tube Roll with the ZMA yet?
Reply #481 - 08/31/18 at 01:46:06
 
I run the 7581A's at 45, 50, 55 & 60 from ear. The 6P, KT88 and my KT66 don't have this range. Just, one more thing I love about the 75's.

Cool you got the JJ 7027A's. I will try the T-SOL's.
Back to top
 
 

Room Treats-M.Green & mine
Sony TPort
Illuminati D60
Shunyata Z-Alpha DigPcord
Decware ZDSD DAC
Kimber Select KS1030
XLOProPcord
Decware ZMA/25th Mods
Kimber Select KS6063
Acoustic Zen Adagio/Modified
Kimber PK10 Palladian from wall
to PS Audio P3
  IP Logged
Jeff of Arabica
Seasoned Member
****


Name the greatest of
all inventors...
Accident.

Posts: 916
Re: Anyone Tube Roll with the ZMA yet?
Reply #482 - 08/31/18 at 05:58:45
 
Quote:
My TS 7581a's are rated at 35w and I'm running them at 50ma, but by your calculations, I could bump them up to 63ma or so.  Did I get that right?  Question is, should I bump them up?


Absolutely Norm!  You have nothing to lose.  Try them TS’s at 64mA and see what you think.  If you don’t prefer that setting, step decrease the current until you find that sweet spot for you and your system.
Back to top
 
 

Canary Audio Grand Reference//ZMA//Zen Ultra//Taboo MKIII//PS Audio DirectStream DAC + Memory Player + P10//Canary Audio MC-10 Phono Stage//London Decca Reference//Dynavector DV-507 MKII//SonoruS Reel-to-Reel w/ tube playback pre-amp//Tannoy Westminster Speakers
  IP Logged
Archie
Seasoned Member
****




Posts: 1882
Re: Anyone Tube Roll with the ZMA yet?
Reply #483 - 08/31/18 at 15:36:04
 
Still no word on my ZMA.
Back to top
 
 

Technics 1200G TT w/ Ortofon Jubilee MC cart
ZMC1
ZP3 (25th A Mods)
ZR2 (25th A Mods)
CSP3 (25th A mods)
ZMA (25th A mods)
ZLC
Homemade Big Betsy Speakers
Silver Cabling
DIY Isolation platforms under amps & TT.
  IP Logged
NormD
Seasoned Member
****




Posts: 199
Re: Anyone Tube Roll with the ZMA yet?
Reply #484 - 08/31/18 at 21:31:35
 
Archie: How long has Steve had it.  I’m thinking of sending in my ZMA after DecFest.
Back to top
 
 

OPPO Sonica DAC
Technics SL-1200M3D Turntable
SoundSmith The Voice cartridge
JRMedia Center running on a MacMini
Oppo 103D for video
Marantz AV8802a Pre
ZTPre & ZMA for Stereo
Rotel RMB-1585 amp
Focal Electra 1038Be speakers (93 db)
2Hsu Research ULS-15 M
  IP Logged
Archie
Seasoned Member
****




Posts: 1882
Re: Anyone Tube Roll with the ZMA yet?
Reply #485 - 08/31/18 at 21:38:25
 
He received it a week ago Wednesday.  I just talked to him today and he has it on his bench.  Devon said that there were a few that have come in.  I'm guessing you'd better be prepared for 2 to 3 weeks based on my experience this time.  For past repairs/upgrades, things happened faster.

BTW, I'm going with all of the upgrades despite already having the Red caps.  No stepped attenuator though as Steve didn't recommend it.  I'm also having my meters fixed/upgraded.
Back to top
 
 

Technics 1200G TT w/ Ortofon Jubilee MC cart
ZMC1
ZP3 (25th A Mods)
ZR2 (25th A Mods)
CSP3 (25th A mods)
ZMA (25th A mods)
ZLC
Homemade Big Betsy Speakers
Silver Cabling
DIY Isolation platforms under amps & TT.
  IP Logged
stone_of_tone
Seasoned Member
****


Listen Often/Listen
Deep

Posts: 3217
Re: Anyone Tube Roll with the ZMA yet?
Reply #486 - 09/05/18 at 21:37:30
 
Cool Arch....you should get her back soon. I'm going to wait until after the New Year/send mine in. With Decfest coming and post orders to that/a good thing! .... + Then, the Holidays....I won't be able to part with my ZMA till January. $1530 + shipping to and from....worth it.

ZMA is warmed up...nice being home from work at 3! But, I start at 6 am.

Anywho, ZMA time!  ....with a new found favorite: VELVELTEEN HABIT, IPA...from Ale Asylum.  HEAVEN, after a long day (with ZMA)!

https://www.beeradvocate.com/beer/profile/13837/152208/










Listening Room:


Room Treatments from Michael Green & my Home Brew

Sony as Transport (DVP-NS57P)
Illuminati D-60 Digital Coax IC ~.5 meter

Shunyata Research Zitron Alpha Digital Power Cord to ZDSD {Significant}

Decware ZDSD DAC / Recorder
***************************************************************
W/Steve's Output Transformer's/kicking to the Curb quite a few superb DAC'S
***************************************************************
(@ -20 Ref Level, @ 16/192)
.....0.0, -0.5 or -1.0dB/Input Volume

WBT-0102Ag RCA Kimber Select KS1030 ~.75 meter

Decware Zen Mystery Amplifier
~***********************~
NOS/Platinum/Mullard E188CC/7308's in my A12 an B12 Input positions Cryogenic~NOS/Platinum/Telefunken E88CC for Inverter Tubes~NOS RCA 0A3's & matched Quad/Tung-Sol Cryo'd 7581A's, Reflector Cryo'd 6P's or Gold Lion KT88's Cryo'd

***************************************************
Kimber Select KS6063 Speaker Cable 8ft WBT-0681-Ag Spades
***************************************************

Acoustic Zen Adagio - Black Pearl (Modified)
.....enjoying from 8 ohm ZMA Taps

Caintuck Audio Eminence Alpha 15" OB BASS Unit
Auralex Subdude




Acoustic Zen Adagio's x-over's Modified/Full Range with Mundorf MCap Supremes-single Cap to each Tweeter/4.5k cross
(Gutted: 3kHz/18dB/Octave, Linkwitz/Riley Crossovers....with all crappy parts = gone)


XLO Pro Power Cord to ZMA
PS Audio P3 Power Plant / Pangea AC-9SE from wall to P3
(Transport & ZDSD, Regenerated/*120*~ Multiwave off...ZMA on High Current Output)
System configured/on floor/Townshend CD Seismic Sink deployed & other isolation devices.





~Constants:
NOS/Platinum/Telefunken 6922/E88CC for Inverter Tubes (yes/the painfully expensive ones, from Upscale Audio = worth it, yes)
NOS RCA 0A3's.

Rotation/Power Quads:
~Matched Quad's~

Tung-Sol Cryo'd 7581A's
Reflector Cryo'd 6P's
Gold Lion KT88's Cryo'd
PENDING PURCHASE ~ GL KT77'S or T-Sol 7027A's.


Rotation/Input Tubes:
~NOS Platinum Tubes from Upscale Audio~

(Great Britain) Mullard 7308/E188CC ~  2 pair (both pair Cryogenic)
(US/Great Britain) Ediswan CV2492/6922 ~ 2 pair (one pair Cryogenic)
(Hungary) Tungsram 6922/E88CC ~ 1 pair
(Hungary) Tungsram PCC88/7DJ8 ~ 1 pair

~Control/came with ZMA~
(Russia) 6N23P ~ 2 pair.
Back to top
 
 

Room Treats-M.Green & mine
Sony TPort
Illuminati D60
Shunyata Z-Alpha DigPcord
Decware ZDSD DAC
Kimber Select KS1030
XLOProPcord
Decware ZMA/25th Mods
Kimber Select KS6063
Acoustic Zen Adagio/Modified
Kimber PK10 Palladian from wall
to PS Audio P3
  IP Logged
NormD
Seasoned Member
****




Posts: 199
Re: Anyone Tube Roll with the ZMA yet?
Reply #487 - 09/06/18 at 01:32:31
 
Just sent my ZMA into the mothership. Hopefully , Steve will get to it before DecFest, but if not I am in the queue.
Back to top
 
 

OPPO Sonica DAC
Technics SL-1200M3D Turntable
SoundSmith The Voice cartridge
JRMedia Center running on a MacMini
Oppo 103D for video
Marantz AV8802a Pre
ZTPre & ZMA for Stereo
Rotel RMB-1585 amp
Focal Electra 1038Be speakers (93 db)
2Hsu Research ULS-15 M
  IP Logged
stone_of_tone
Seasoned Member
****


Listen Often/Listen
Deep

Posts: 3217
Re: Anyone Tube Roll with the ZMA yet?
Reply #488 - 09/06/18 at 11:16:03
 
Very nice Norm. I look forward to your and Archie's impressions in the coming weeks. I bet it will motivate me to send mine or drive it to Decware.
Back to top
 
 

Room Treats-M.Green & mine
Sony TPort
Illuminati D60
Shunyata Z-Alpha DigPcord
Decware ZDSD DAC
Kimber Select KS1030
XLOProPcord
Decware ZMA/25th Mods
Kimber Select KS6063
Acoustic Zen Adagio/Modified
Kimber PK10 Palladian from wall
to PS Audio P3
  IP Logged
stone_of_tone
Seasoned Member
****


Listen Often/Listen
Deep

Posts: 3217
Re: Anyone Tube Roll with the ZMA yet?
Reply #489 - 09/08/18 at 15:23:49
 
I posted on the general forum, I can't let Archie & Norm have all the fun with their enhanced ZMA's next month!    ;D

Spend, when she comes back....seasoning back in....then resume tube rolling, ie-get the Tung-Sol 7027A's..... .
Back to top
 
 

Room Treats-M.Green & mine
Sony TPort
Illuminati D60
Shunyata Z-Alpha DigPcord
Decware ZDSD DAC
Kimber Select KS1030
XLOProPcord
Decware ZMA/25th Mods
Kimber Select KS6063
Acoustic Zen Adagio/Modified
Kimber PK10 Palladian from wall
to PS Audio P3
  IP Logged
Jeff of Arabica
Seasoned Member
****


Name the greatest of
all inventors...
Accident.

Posts: 916
Re: Anyone Tube Roll with the ZMA yet?
Reply #490 - 09/08/18 at 17:28:04
 
Ha!  That a boy Stone!  You will not regret!  

With much needed influence from Wil and BonnyA, last week I decided to finish the enhancement project and move forward with power supply bypass caps.  I have the amazing 47uF Mundorf TubeCaps installed and wanted to follow Steve's lead and further bypass those caps.  I used the same values as BonnyA, .47uF and .1uF caps.  Due to the size of the TubeCaps, I wasn't sure I could find room for these bypass caps. It was close.  There was one space left on each side where they fit like a glove.  it took a little Tetrus skill but I found a great spot.  

The bypassing has further enhanced the high frequency detail and speed, as well as another slight step in lowering the noise floor.  These bypass caps made a noticeable improvement and they are not even close to burning in (the caps I used came with a 350 hour burn in recommendation).  

All in all, time and money well spent!  ...the icing on the cake  :)

Stone, I know it is a pain to send it in a be without, and it is not an insignificant expense, but the level of satisfaction I have with my ZMA post-enhancement is truly off the charts.  
Back to top
 
 

Canary Audio Grand Reference//ZMA//Zen Ultra//Taboo MKIII//PS Audio DirectStream DAC + Memory Player + P10//Canary Audio MC-10 Phono Stage//London Decca Reference//Dynavector DV-507 MKII//SonoruS Reel-to-Reel w/ tube playback pre-amp//Tannoy Westminster Speakers
  IP Logged
stone_of_tone
Seasoned Member
****


Listen Often/Listen
Deep

Posts: 3217
Re: Anyone Tube Roll with the ZMA yet?
Reply #491 - 09/09/18 at 00:34:32
 
You know it Jeff. Thanks for starting it all with the Exercise in speed Thread.
Back to top
 
 

Room Treats-M.Green & mine
Sony TPort
Illuminati D60
Shunyata Z-Alpha DigPcord
Decware ZDSD DAC
Kimber Select KS1030
XLOProPcord
Decware ZMA/25th Mods
Kimber Select KS6063
Acoustic Zen Adagio/Modified
Kimber PK10 Palladian from wall
to PS Audio P3
  IP Logged
Jeff of Arabica
Seasoned Member
****


Name the greatest of
all inventors...
Accident.

Posts: 916
Re: Anyone Tube Roll with the ZMA yet?
Reply #492 - 09/09/18 at 02:38:16
 
For sure.  It has been a lot of fun!  I do adore this amplifier and it was never my intent to part with it.  So, I figured why not embark on this adventure after Steve had so much such in this area of the amplifier in his 25th Anniversary Zen.  

Honestly, I can't wait for you to get your amp back so I can read your impressions Smiley

This is no bigger fan of the ZMA on this forum than you!
Back to top
 
 

Canary Audio Grand Reference//ZMA//Zen Ultra//Taboo MKIII//PS Audio DirectStream DAC + Memory Player + P10//Canary Audio MC-10 Phono Stage//London Decca Reference//Dynavector DV-507 MKII//SonoruS Reel-to-Reel w/ tube playback pre-amp//Tannoy Westminster Speakers
  IP Logged
stone_of_tone
Seasoned Member
****


Listen Often/Listen
Deep

Posts: 3217
Re: Anyone Tube Roll with the ZMA yet?
Reply #493 - 09/09/18 at 13:20:46
 
Yes, I'm excited about receiving her back and even without the 4th mod/continuing with my red Mallory's, will be interesting to then put the Nichicon's in 6 or 7 months later. I can do it at work, however, this would be a good excuse to drive and see Steve and DeVon for completion.

No, I think you're a huge fan of this Amp too J of A. Great point, reading of the 25th UFO from Steve and you saying what if? ....for our ZMA's.

Plus, I want to acknowledge vyukyong, whom back in the summer of 2014' got me thinking what if? The Obbligato caps/and such.....I know you drew inspiration from too and went even further with your stellar Mundorf insertions. The single cap Mundorf's, totally recreated my Adagio Loud Speakers! Mr. Lee's, custom German made woofer's with under hung voice coils with his inhouse 1.75 inch ribbon tweeter's + his beautiful transmission lines/ Cabs/ function & form. ......with the nuts of the ZMA.
Back to top
 
 

Room Treats-M.Green & mine
Sony TPort
Illuminati D60
Shunyata Z-Alpha DigPcord
Decware ZDSD DAC
Kimber Select KS1030
XLOProPcord
Decware ZMA/25th Mods
Kimber Select KS6063
Acoustic Zen Adagio/Modified
Kimber PK10 Palladian from wall
to PS Audio P3
  IP Logged
stone_of_tone
Seasoned Member
****


Listen Often/Listen
Deep

Posts: 3217
Re: Anyone Tube Roll with the ZMA yet?
Reply #494 - 09/09/18 at 16:06:25
 
I am just slam rocking my ZMA right now with some FUNK!
WAHOOOOOOOOOOO!
Damn, I do love this AMP!

Tube comp' Ediswan's/inputs
Telefunk's invert's (you know the ones....and if you don't - you  should)
T SOL 7581A's...................love them.

VIKINGS GAME AT NOON!
.....her brother has the opening tic's....Sue and I go to US Bank in mid October/Arizona game....season tic's in her family since 1964...we keep the tradition alive!  CTE will probably end the league in 15/by, 20 more years...but most of them say they would do it all over again....and current player's know the truth now.
Back to top
 
 

Room Treats-M.Green & mine
Sony TPort
Illuminati D60
Shunyata Z-Alpha DigPcord
Decware ZDSD DAC
Kimber Select KS1030
XLOProPcord
Decware ZMA/25th Mods
Kimber Select KS6063
Acoustic Zen Adagio/Modified
Kimber PK10 Palladian from wall
to PS Audio P3
  IP Logged
stone_of_tone
Seasoned Member
****


Listen Often/Listen
Deep

Posts: 3217
Re: Anyone Tube Roll with the ZMA yet?
Reply #495 - 09/19/18 at 21:38:56
 
Over in the Developement Thread I posted about getting an Torii JR/25th.
I look forward to Steve's prose, applying the 25th mod's.

MY thoughts to buy an Torii JR/25th. Sure, it will cost me 16 or 1800 over the ZMA enhancements. However, it is a whole other Amp in chassis and leaves my ZMA intact for comparison.



Lets run wild with the scenarios........

I love the JR/25th so much - I need to 25th my ZMA

I love the JR/25th - but, my ZMA is still something Special with more power (or maybe not so much more power - the JR will do some serious peaks - I think 85 watts - Steve wrote in the JR Copy)......I just want to keep my ZMA as is.....great Special Animal - je ne sais quoi!

I love the JR/25th so much ......maybe I sell my ZMA! ....sacrilege.....

Or, maybe......with a good taste of the JR/25th mod's....ZMA is just fine and I sell the JR?

Or, the best scenerio....I keep both....cause I can't be without either.

I'm doing it!

PS ~ I know ~ I know ....this is a tube rolling Thread...I will get back on track and order the TSOL 7027A's soon.  ....to busy with the 7581A's right now.
Back to top
 
 

Room Treats-M.Green & mine
Sony TPort
Illuminati D60
Shunyata Z-Alpha DigPcord
Decware ZDSD DAC
Kimber Select KS1030
XLOProPcord
Decware ZMA/25th Mods
Kimber Select KS6063
Acoustic Zen Adagio/Modified
Kimber PK10 Palladian from wall
to PS Audio P3
  IP Logged
Archie
Seasoned Member
****




Posts: 1882
Re: Anyone Tube Roll with the ZMA yet?
Reply #496 - 09/22/18 at 01:38:07
 
Well, I got my modified ZMA back two days ago and after suffering along for a month with an NAD SS amp, of course my sound is back to amazing!

There may be a lot of burn in required but I seem to be hearing an increase in "realism" and a tightness to the sound analogous to high performance steering in a car.  Since I went so long without my ZMA I am having a hard time deciding what's new about the sound given the upgrades.  I think with time, as I go through my vinyl collection, I'll be able to tell more as I'm sure I'll be hearing things I've never heard before (some of that already).

One interesting thing is that my transformers don't seem to get as hot or hot as fast since the upgrade despite my biasing at 68mA instead of 56mA for the 7851As.  I have no idea why this would be.

Along with the upgrades, Steve replaced my meters with back-lit Western Electric meters.  I had the original blue LED lights in my meters but the lights stopped working a couple years ago.  Although the blue lights looked pretty cool, these back-lit WE meters are vastly better and very practical since the meters are now easy to read in low/no light situations.  I would recommend that Steve make these the standard ZMA meter and failing that, anyone upgrading or starting new, ought to spring for them.  One more thing about these WE meters.  Im wondering if they are somehow more responsive than the old meters as I'm seeing the needles start to twitch at a lower sound level.  The amp still cranks with no distortion, that I can hear.

That's all for now other than to say that I am very glad I went ahead and upgraded and I'm looking forward to further listening as things season more and more.   Smiley

(Stone, I don't know what to tell you.  I know you've been on the fence about upgrading and if you were anyone else, I'd tell you to jump in!  But I wouldn't want to be responsible for any disappointment since you love your stock ZMA so much.)
Back to top
 
 

Technics 1200G TT w/ Ortofon Jubilee MC cart
ZMC1
ZP3 (25th A Mods)
ZR2 (25th A Mods)
CSP3 (25th A mods)
ZMA (25th A mods)
ZLC
Homemade Big Betsy Speakers
Silver Cabling
DIY Isolation platforms under amps & TT.
  IP Logged
stone_of_tone
Seasoned Member
****


Listen Often/Listen
Deep

Posts: 3217
Re: Anyone Tube Roll with the ZMA yet?
Reply #497 - 09/22/18 at 15:17:43
 
Point well taken Archie. I am going to stick with my ZMA as is. I run it direct 90% of the time via Steve's ZDSD output stage. I would buy immediately an ZBIT if I change DACS (need Steve's voltage output to ZMA/to run direct). When I want to give my ZMA, a big swinging grown a pair.....I put my Audio Research Line Stage in (very good voltage output).

Cool, the power Tranny's run that cool with the bypass (?) maybe/portion of the mod.... Maybe Steve will read and chime in. Whether intentional or a byproduct of the mod....this bodes well to run KT88's longer or as long as you want. Steve did modify his ZMA to run KT88's....I do recall..... . I'm fine running KT88's/only 4 to 6 hour sessions. My love is with the 7581A's/power tubes and input NOS vintage rare tubes. 7027A's will come in as well...eventually.

I have the new backlit meter's too. The symmetry and beauty of this Amp is off the charts.

Question: I thought the math from J of A and you put the awesome 35w plate dissapation 7581A's at 64mA max? I love mine at 50! .....up to 58.
Back to top
 
 

Room Treats-M.Green & mine
Sony TPort
Illuminati D60
Shunyata Z-Alpha DigPcord
Decware ZDSD DAC
Kimber Select KS1030
XLOProPcord
Decware ZMA/25th Mods
Kimber Select KS6063
Acoustic Zen Adagio/Modified
Kimber PK10 Palladian from wall
to PS Audio P3
  IP Logged
stone_of_tone
Seasoned Member
****


Listen Often/Listen
Deep

Posts: 3217
Re: Anyone Tube Roll with the ZMA yet?
Reply #498 - 09/22/18 at 15:50:44
 
Speaking of input NOS vintage rare tubes.

I am so jones-in to purchase the Mazda 7308/E188CC ultra premium 1960's France Large Halo getter gold pins!  (Pair)

....must stop....not pick up phone on Monday....block phone from Hoffman Estates.....block....I repeat block!   Grin Grin

Actually, after this tube purchase...I'm going to get a ZBIT. I need to hear by comparison to the inboard output stage. Dampening down the XLR output of the ZDSD via the ZBIT and riding the gain of the ZMA RCA input; I finally need to compare and HEAR!
Back to top
 
 

Room Treats-M.Green & mine
Sony TPort
Illuminati D60
Shunyata Z-Alpha DigPcord
Decware ZDSD DAC
Kimber Select KS1030
XLOProPcord
Decware ZMA/25th Mods
Kimber Select KS6063
Acoustic Zen Adagio/Modified
Kimber PK10 Palladian from wall
to PS Audio P3
  IP Logged
Jeff of Arabica
Seasoned Member
****


Name the greatest of
all inventors...
Accident.

Posts: 916
Re: Anyone Tube Roll with the ZMA yet?
Reply #499 - 09/22/18 at 16:50:39
 
Archie,
Glad to hear your ZMA is back!  There will be some burn-in time with the new caps and resistors for sure, but my bet is the aural improvements are already there, you just had the unfortunate circumstance of not being able to do more of an A/B comparison with the ZMA.  

As you stated, one of the big changes, at least for me was the increase in audible detail.  The information was always there but the lowering of the noise floor and increase in the amps response with the faster caps is bringing those micro-details to the forefront where you can hear them.  

As you run your reference library through the new ZMA, I have a strong feeling it is going to be all so evident the improvements these mods have brought about.  

How is the bass?  That was a very noticeable change for me.  

All in all, give it some time to settle.  In many ways it is like a brand new amp with all of the resistor and capacitor additions.  You should hear immediate differences but there is no double things will continue to improve over time.  
Back to top
 
 

Canary Audio Grand Reference//ZMA//Zen Ultra//Taboo MKIII//PS Audio DirectStream DAC + Memory Player + P10//Canary Audio MC-10 Phono Stage//London Decca Reference//Dynavector DV-507 MKII//SonoruS Reel-to-Reel w/ tube playback pre-amp//Tannoy Westminster Speakers
  IP Logged
Pages: 1 ... 8 9 10 11 12 ... 15
Send Topic Print