Welcome, Guest. Please Login or Register
Decware Audio Forums
11/26/22 at 16:30:21 




Pages: 1 ... 14 15 16 
Send Topic Print
Anyone Tube Roll with the ZMA yet? (Read 9867 times)
Archie
Seasoned Member
****




Posts: 2731
Re: Anyone Tube Roll with the ZMA yet?
Reply #750 - 12/13/21 at 17:35:16
 
I'd love to try some KT77s but my tube budget is currently limited to known tubes.

If you have a ZMA it does a pretty good job as a "tube tester."  I sparked one of my 7581As and it was on the side that was requiring a lot of bias offset to bring the pair together.  

The way you describe "dry bass" suggests to me that I don't have that problem, generally.  Although, that could be why I never really liked KT66s in my amp.  (I always attributed it to relative mid range lack.)
Back to top
 
 

ZLC
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)
Homemade Big Betsy Speakers (F15s)
Silver Cabling
DIY Isolation platforms under amps & TT.
  IP Logged
__Jon__
Verified Member
**




Posts: 30
Re: Anyone Tube Roll with the ZMA yet?
Reply #751 - 12/22/21 at 06:17:41
 
I also found the new production kt66s somewhat recessed in the midrange, both in the ZMA and my lampizator DAC (which has a tube buffer). It was like female vocalists were a couple steps back from the band. Perhaps interestingly, I tried a pair of lightly used NOS GEC KT66s in the DAC and everything was noticeably better. Not the absolute best midrange but very good and it did so many other things remarkably well. Too expensive to consider in the ZMA though.

I’m also really happy with the 7027as but sometimes get an itch to change things. I plan to try the new production Gold Lion KT77s in the next couple months. Will post with thoughts if and when.
Back to top
 
 
  IP Logged
Archie
Seasoned Member
****




Posts: 2731
Re: Anyone Tube Roll with the ZMA yet?
Reply #752 - 12/22/21 at 06:28:00
 
I've liked pretty much every tube I've tried better than KT66s.  Never had anything other than new Tung-Sol and Gold Lion though.
Back to top
 
 

ZLC
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)
Homemade Big Betsy Speakers (F15s)
Silver Cabling
DIY Isolation platforms under amps & TT.
  IP Logged
HockessinKid
Seasoned Member
****




Posts: 892
Re: Anyone Tube Roll with the ZMA yet?
Reply #753 - 02/18/22 at 13:05:45
 
Yikes, sporadic noisy right channel this week in my system. Started switching positions with KT77 power tubes in the ZMA thinking they were the culprit. Wrong!

This morning really high static sound coming from the right channel, ugh. Quickly powered down the whole system. After checking my tubes, I noticed a discoloration on the top getter in my right channel Sylvania OA3 voltage regulator tube. Went from steel gray to brown copper with some dark discoloration of the glass outside the getter.

I think I was moments away from a flash bang total tube failure. Thankfully I have several back up NOS pairs. Anyway, just a note for ZMA owners to keep an eye out on your voltage regulator tubes. I'm guessing these had 6,000 - 7,000 hours on them. Whew!

HK

Back to top
 
 

Nottingham Interspace TT w/ Dynavector 20x2 LO cart + Modwright PH 9.0X phono OR Modwright modded Cambridge CNX V2 > CSP3-A preamp > ZMA-A amp > PI Audio UberBUSS > Omega SAHO XRS or Caintuck Audio Lii15 Magnum speakers > Snake River Audio & ZenWave cables.
  IP Logged
NormD
Seasoned Member
****




Posts: 234
Re: Anyone Tube Roll with the ZMA yet?
Reply #754 - 03/14/22 at 00:58:01
 
I was going through my tube collection looking to thin the herd. I came across a matched quad of RFT EL34’s. These are by far the the best tubes I’ve tried. Noticeably better in midrange clarity than the GL KT77’s. I have plenty of bass and treble with my Sopra 2 speakers. For some reason I had put them aside a few years ago - likely before the 25th anniversary mods and definitely before I went to 6N5P red tips for the input stage.
Back to top
 
 

OPPO Sonica DAC
Technics SL-1200M3D Turntable
SoundSmith The Voice cartridge
JRMedia Center running on a MacMini
Panasonic DP-UB820
Marantz AV8802a Pre/Rotel RMB-1585 Surround
ZTPre & ZMA Stereo
Focal Sopra No. 2 speakers (91 db)
2 Hsu ULS-ULS-15 MK2 Subs
  IP Logged
HockessinKid
Seasoned Member
****




Posts: 892
Re: Anyone Tube Roll with the ZMA yet?
Reply #755 - 07/08/22 at 14:31:29
 
Well the quad of Gold Lion KT77 tubes only lasted 7 months, 😭. Two tubes started getting noisy then flashed up and died this morning.

I've put my quad of TAD 7027A tubes back in this morning. The cost of GL KT77's has doubled with the Russian shipping embargo, so I'll wait until prices become more reasonable before I spring for another set.

HK
Back to top
 
 

Nottingham Interspace TT w/ Dynavector 20x2 LO cart + Modwright PH 9.0X phono OR Modwright modded Cambridge CNX V2 > CSP3-A preamp > ZMA-A amp > PI Audio UberBUSS > Omega SAHO XRS or Caintuck Audio Lii15 Magnum speakers > Snake River Audio & ZenWave cables.
  IP Logged
Carlsbad
Seasoned Member
****




Posts: 135
Re: Anyone Tube Roll with the ZMA yet?
Reply #756 - 07/19/22 at 05:29:56
 
Well I've, over several days, read this entire thread.  Very informative.  I wish it were as active as it once was.  

I have some Tung Sol 7581As on order.  I just removed my GL KT66s and am listening to Russian 6P3S quad.  Nice tubes, great sounstage, maybe a bit shy on bass.   Looking for some 7027As.  Unfortunately I bought my ZMA at just the wrong time tube wise.  Some amazing tube prices mentioned in this thread.  Some amazing in a different manner prices out there now.

On input and inverter tubes, it seems very hard to find any of the recommended tubes, Telefunken, Tungsram, Mullard and Ediswan.  There is a seller in the ukraine that has some tungsrams but his photos show them in the same packaging as several other bulk tubes he carries so I wonder if they are Chinese knockoffs.

Finally, it seems member stone_of_tone was posting enthusiasticly in early 2019 and then just quit posting.  His last post talked about tube rolling and working 31.5 hours over the next 3 days.  I hope he is ok.  I enjoyed his comments.

Jerry
Back to top
 
 

Decware ZMA w/ 25th mods, input selector switch
Chord Dave DAC with M-scaler
Innuos Zenith Mk3 streamer fed by EtherRegen
Tekton Encore Speakers
  IP Logged
Carlsbad
Seasoned Member
****




Posts: 135
Re: Anyone Tube Roll with the ZMA yet?
Reply #757 - 08/01/22 at 23:25:01
 
Purple/blue voltage regulator tubes?  Steve has a beautiful photo of a VR90 style regulator tube that glows blue on the ZMA page.  Anybody know what specific tube it is?  

I know it is (at least must be) and argon tube since argon glows that color.  Neon glows orange which is what we see in the normal OA3's we use.

I've bought several older argon tubes.  None glow much at all and none sound as good as the standard OA3s.

I'd enjoy trying the tube pictured if anyone knows what it is.  

https://www.decwareproducts.com/zma
Scroll down about 8 pages.

thanks,
Jerry
Back to top
 
 

Decware ZMA w/ 25th mods, input selector switch
Chord Dave DAC with M-scaler
Innuos Zenith Mk3 streamer fed by EtherRegen
Tekton Encore Speakers
  IP Logged
Lon
Seasoned Member
****


"Love without
guts is
worthless!"
Philip K. Dick

Posts: 20358
Re: Anyone Tube Roll with the ZMA yet?
Reply #758 - 08/01/22 at 23:37:43
 
A VR90 is a 0B3 tube. I use that tube in place of 0A3 myself--in my system with my other tubes that sounds best. Most of mine glow a lavender/purple color--haven't seen one that glows blue.
Back to top
 
 

HR-1,ZTPRE,ZBIT,ZROCK2,SE84UFO3-25th x2, CSP3-25th.Taboo Mk IV;Rega RP3 all GrooveTracer mods;PSAudio:PST+DSD,P15,NPC,PowerBases,AC-12 pwr cbls,Reference spkrcbls; Mapleshade SamsonV3;VooDoo:Cremona+Amati interconnects, IsoPods; headphones:Sennheiser HD800S,ZMF Or
  IP Logged
Carlsbad
Seasoned Member
****




Posts: 135
Re: Anyone Tube Roll with the ZMA yet?
Reply #759 - 08/02/22 at 01:23:43
 
Lon,
What manufacture tube are you using?  Do you have a source?  thanks, Jerry
Back to top
 
 

Decware ZMA w/ 25th mods, input selector switch
Chord Dave DAC with M-scaler
Innuos Zenith Mk3 streamer fed by EtherRegen
Tekton Encore Speakers
  IP Logged
Lon
Seasoned Member
****


"Love without
guts is
worthless!"
Philip K. Dick

Posts: 20358
Re: Anyone Tube Roll with the ZMA yet?
Reply #760 - 08/02/22 at 01:48:50
 
At the moment I am using Sylvania, "bottle-shape" type. I also use RCA and Westinghouse -- all three work really well with my Monoblocks. I get tubes from eBay.
Back to top
 
 

HR-1,ZTPRE,ZBIT,ZROCK2,SE84UFO3-25th x2, CSP3-25th.Taboo Mk IV;Rega RP3 all GrooveTracer mods;PSAudio:PST+DSD,P15,NPC,PowerBases,AC-12 pwr cbls,Reference spkrcbls; Mapleshade SamsonV3;VooDoo:Cremona+Amati interconnects, IsoPods; headphones:Sennheiser HD800S,ZMF Or
  IP Logged
Carlsbad
Seasoned Member
****




Posts: 135
Re: Anyone Tube Roll with the ZMA yet?
Reply #761 - 08/02/22 at 12:31:31
 
Thanks Lon.
Back to top
 
 

Decware ZMA w/ 25th mods, input selector switch
Chord Dave DAC with M-scaler
Innuos Zenith Mk3 streamer fed by EtherRegen
Tekton Encore Speakers
  IP Logged
__Jon__
Verified Member
**




Posts: 30
Re: Anyone Tube Roll with the ZMA yet?
Reply #762 - 08/02/22 at 18:56:33
 
And in case some don't remember, you can't change the OA3 tubes to OB3 or OC3 in the ZMA like you can in some of the other Decware offerings. I haven't personally seen any Argon OA3 tubes but I only have 50 or so  :P. When searching for these types of tubes remember to search with a "Zero" at the start as well as the letter "O." They are listed variably.
Back to top
 
 
  IP Logged
HockessinKid
Seasoned Member
****




Posts: 892
Re: Anyone Tube Roll with the ZMA yet?
Reply #763 - 08/03/22 at 13:49:43
 
Just scored another quad, w/ less than 50 hours, of Gold Lion KT77's for a screaming deal. Should have them back in the ZMA shortly. Looking forward to getting that sound back.

HK

Back to top
 
 

Nottingham Interspace TT w/ Dynavector 20x2 LO cart + Modwright PH 9.0X phono OR Modwright modded Cambridge CNX V2 > CSP3-A preamp > ZMA-A amp > PI Audio UberBUSS > Omega SAHO XRS or Caintuck Audio Lii15 Magnum speakers > Snake River Audio & ZenWave cables.
  IP Logged
Carlsbad
Seasoned Member
****




Posts: 135
Re: Anyone Tube Roll with the ZMA yet?
Reply #764 - 08/03/22 at 22:15:29
 
HK,
What are you biasing the KT77s at?  50mA is about 20W on a 25W rated tube which isn't terribly conservative but isn't aggressive either.  You should get pretty good life at 50mA.  Jerry
Back to top
 
 

Decware ZMA w/ 25th mods, input selector switch
Chord Dave DAC with M-scaler
Innuos Zenith Mk3 streamer fed by EtherRegen
Tekton Encore Speakers
  IP Logged
Carlsbad
Seasoned Member
****




Posts: 135
Re: Anyone Tube Roll with the ZMA yet?
Reply #765 - 08/05/22 at 13:49:29
 
Jon
I want to politely challenge (because I don't really know) your statement that you can't use the VR90 in the ZMA.  On the ZMA page Steve has a photo of one and the following words:

"This beautiful tube is a variant of the OA3 regulator tube. It is a VR90 which drops the voltage to the input stage by around 15 volts.  This can be just enough to tickle your exotic N.O.S. 6922 or 7DJ8 inputs tubes into a new level of nirvana.  There are actually three of these tubes you can work with that will give you three different sounds."

So I think Steve is saying that raising the voltage from 75 to 90 is ok.  It doesn't change any of the gain settings.  But I would like to know for sure.

I have to admit that I interpreted this to mean that the VR90 was interchangeable with the OA3, i.e., they are both 90 v regulator tubes.  I ordered a couple and tried them.  Didn't like the sound as much.  I blamed it on poor quality used VR90s that I was able to find.  I just bought a few more old VR90s and I'll try them soon.  

But I haven't found anything that can sound as good as the true NOS sylvannia OA3s that the amp is supplied with.

Jerry
Back to top
 
 

Decware ZMA w/ 25th mods, input selector switch
Chord Dave DAC with M-scaler
Innuos Zenith Mk3 streamer fed by EtherRegen
Tekton Encore Speakers
  IP Logged
Carlsbad
Seasoned Member
****




Posts: 135
Re: Anyone Tube Roll with the ZMA yet?
Reply #766 - 08/05/22 at 18:22:53
 
Update to above post.  Just today I received in the mail some true, sealed-in-the-box NOS sylvania VR-90s dated 1954 (2 years older than me).  I put them in and they sound great, not sure if better than the OA3s but I'll do some A/B testing on them later.  May take a while since my A/B tests are usually hours long, not minutes.

So I would really like confirmation that VR-90s are good.  Am I shortening the life of some of the tubes?  If so, which ones? I'm going to go try to figure out what components are using the regulated voltage.

But right now, things are sounding extremely nice.

Jerry
Back to top
 
 

Decware ZMA w/ 25th mods, input selector switch
Chord Dave DAC with M-scaler
Innuos Zenith Mk3 streamer fed by EtherRegen
Tekton Encore Speakers
  IP Logged
GroovySauce
Seasoned Member
****




Posts: 513
Re: Anyone Tube Roll with the ZMA yet?
Reply #767 - 08/06/22 at 13:41:29
 
VR (Voltage Regulator) tubes drop voltage.

From Wikipedia.com:

Octal-based tubes, 5–40 mA current:
* 0A3 – 75 volts
* 0B3 – 90 volts
* 0C3 – 105 volts (best regulation of these four)
* 0D3 – 150 volts
Miniature tubes, 5–30 mA current:
* 0A2 – 150 volts
* 0B2 – 108 volts (best regulation of these three)
* 0C2 – 72 volts

So a 400v amp with a 0A3 is 325v to the tubes it's connected to. ZMA 0A3 powers the input tubes. I don't know if the 0A3 on the ZMA or Torii MKV power the inverter tubes or not.
Back to top
 
 

Rega P8 | Zephyr MIMC★ | Innuos ZENith MK3 | May KTE DAC | ZP3 25th ZMC1 | ZRock2 25th | EMIA Remote Autoformer | Torii MKV 25th | Snake River Audio Cables | PAP Quintet 15 1.6 Voxativ Custom XO & SRA cables| Torus AVR15 | Acoustic Treatment by Acoustic Fields
  IP Logged
Carlsbad
Seasoned Member
****




Posts: 135
Re: Anyone Tube Roll with the ZMA yet?
Reply #768 - 10/07/22 at 13:24:53
 
After listening to the VR90s for a while and going back and forth, I decided I like the OA3s that Steve recommends the best.  Been back in the amp for quite a while now.  

So after lots of tube rolling I've decided I like the TS 7581A best in the power position.   On the input tube I'm using the red tipped 6N5P NOS Russian tubes and for the driver I'm using my favorite old WE 396A with an adapter.  

Jerry
Back to top
 
 

Decware ZMA w/ 25th mods, input selector switch
Chord Dave DAC with M-scaler
Innuos Zenith Mk3 streamer fed by EtherRegen
Tekton Encore Speakers
  IP Logged
Carlsbad
Seasoned Member
****




Posts: 135
Re: Anyone Tube Roll with the ZMA yet?
Reply #769 - 10/12/22 at 04:39:02
 
Another update.  Got another pair of WE 396 and have them in both driver and input locations.  superb.
Back to top
 
 

Decware ZMA w/ 25th mods, input selector switch
Chord Dave DAC with M-scaler
Innuos Zenith Mk3 streamer fed by EtherRegen
Tekton Encore Speakers
  IP Logged
Carlsbad
Seasoned Member
****




Posts: 135
Re: Anyone Tube Roll with the ZMA yet?
Reply #770 - 11/01/22 at 03:22:14
 
Anybody tried 350Bs with the ZMA?  What are your results?

thanks,
Jerry
Back to top
 
 

Decware ZMA w/ 25th mods, input selector switch
Chord Dave DAC with M-scaler
Innuos Zenith Mk3 streamer fed by EtherRegen
Tekton Encore Speakers
  IP Logged
GroovySauce
Seasoned Member
****




Posts: 513
Re: Anyone Tube Roll with the ZMA yet?
Reply #771 - 11/01/22 at 15:06:53
 
350b are no longer made AFAIK. The ones I've seen for sale have been $600+ per tube. TubeDepot.com is selling Wester Electric 350b for $1,150 each, almost $4,400 for a quad!

I have not tried them and don't have any plans too.

Back to top
 
 

Rega P8 | Zephyr MIMC★ | Innuos ZENith MK3 | May KTE DAC | ZP3 25th ZMC1 | ZRock2 25th | EMIA Remote Autoformer | Torii MKV 25th | Snake River Audio Cables | PAP Quintet 15 1.6 Voxativ Custom XO & SRA cables| Torus AVR15 | Acoustic Treatment by Acoustic Fields
  IP Logged
Carlsbad
Seasoned Member
****




Posts: 135
Re: Anyone Tube Roll with the ZMA yet?
Reply #772 - 11/01/22 at 19:05:49
 
Groovysauce,  I see from the tubes included with your Torii for sale that you aren't afraid to roll some tubes.  

I too think the WE 350Bs are too expensive.  However, Valve Art made some modern copies.  The more I read about them, the more I see people warning off of them.  However, often such internet wisdom comes from people with original 350Bs for sale. They won't sell if the Valve Art tubes get good reviews.  

Also expensive is the RCA 6L6GC but the GE version is affordable.  

I've been using new tubes.  I have upgraded all my digital system.  The amp is sounding wonderful and I think it is now time to explore NOS.  I'm using WE396 input and driver tubes--have experience with this tube in other amps--and am very happy.  

Welcome any advice you have.
Jerry
Back to top
 
 

Decware ZMA w/ 25th mods, input selector switch
Chord Dave DAC with M-scaler
Innuos Zenith Mk3 streamer fed by EtherRegen
Tekton Encore Speakers
  IP Logged
Carlsbad
Seasoned Member
****




Posts: 135
Re: Anyone Tube Roll with the ZMA yet?
Reply #773 - 11/03/22 at 13:43:50
 
Update on tubes.  I have made a lot of upgrades to my system since I did most of my tube testing.  my entire digital front end has been upgraded, my amp has seen a few upgrades including some new wiring inside and eliminating the fuse (power strainer) in the input.  Not sure I had my PS Audio PP10 at the time I tested tubes.  Here is the list:

TS 7581A--the tubes I've been listening to for months, love them.
TS 7027A--oops, bad tube now fills one channel with static not tested.
Mullard el34   Bland
Golden lion KT66  Good but missing dynamic midrange and highs
TS KT66--the tubes supplied with the amp, the ones i had when i started buying tubes.  i remember them as good.  with the upgrades they are amaing.  the music keeps jumping out at me.  vocals and saxophone are right in the room with me.  Highs are strong.  bass perfect. I guess it makes sense since the amp was built around these tubes.  I wish they made a little more light.  the 7581A tubes look awesome in low light while listening.  Amp light is balanced between the input tubes, power tubes, and regulators.

Ooops, just realized I forgot to test the russian tubes again (whatever the 6l6 equivalent is which I have a set of.

Tubes on my list to try:

GE 6l6GC
807, preferably mullard but a nice set
sylvania 5933

Jerry
Back to top
 
 

Decware ZMA w/ 25th mods, input selector switch
Chord Dave DAC with M-scaler
Innuos Zenith Mk3 streamer fed by EtherRegen
Tekton Encore Speakers
  IP Logged
Carlsbad
Seasoned Member
****




Posts: 135
Re: Anyone Tube Roll with the ZMA yet?
Reply #774 - 11/23/22 at 12:58:10
 
Any body tried 350B?  Tube looks very compatible except the heater current is higher at 1.6A. Anybody know if the ZMA heater circuit will supply the higher current?  

http://www.tubezone.net/pdf/we350b.pdf

Tube looks like it would be fun to try if the heater current works.

Jerry
Back to top
 
 

Decware ZMA w/ 25th mods, input selector switch
Chord Dave DAC with M-scaler
Innuos Zenith Mk3 streamer fed by EtherRegen
Tekton Encore Speakers
  IP Logged
Pages: 1 ... 14 15 16 
Send Topic Print