PK, if you like the sound of the RCA Black plate 12AU7...I do too...you should try a RCA Triple Mica 5814A...that's my favorite so far.  In the 12AX7 spot, so far I've liked the GE Triple mica 5751s best...I've tried a pair of 1957 RCA Black plate 12AX7s and a pair of Raytheon 12AX7s there.  I have one RCA Triple mica 5751 on the way and I'm looking for another one for about $50 to try in the ZP3.  In the 12AU7 spot, I've tried more than a dozen tubes...I've lost count. Ain't this fun?  Mark.

Peter, I definitely will...I'm hoping the RCA triple mica 5751s will beat out the GEs. I'm going to send an email to a favorite seller in the past to see if she has any. What are you running for a rectifier in your ZP3...I'm using a NOS RCA 5y3g and then a NOS RCA OA3 tops it off.

Let me know what you think of the  RCA triple Mica 5814.  Copy the link of what you bought, so I can have a look. Mark.

Peter, the NOS OA3's are dirt cheap, buy several for back up and other Amps in the future...I use them in my newly acquired  SE84ZSM Monoblocks and my Torii MK IV. I've never tried others in this position.

Get rid of that Chinese tube...yes, the RCA 5Y3G works there and seems to be the preferred tube for that position in the opinion of many here.  It's the only one I've used besides the stock one briefly. But if you prefer, you can use a NOS RCA 5U4G...I use these in the Monos...they're nice.

I just went and looked at the owners manual...link below.  And the picture has a 5Y3GT in that spot and on page 4 they talk about the tubes.  It would appear that the ZP3 was originally voiced with the 5Y3 type rectifier but I know the 5U4 types work too.  Mark.

https://www.decware.com/newsite/ZP3%20ownersmanual.pdf

Current tube rolling Favorites:

12AU7 Slot:  NOS RCA 5814A BLACK  P 3 MICA S-RODS

12AX7 Slot:  NOS Telefunken 12AX7



Other 12AX7 tubes that I tried, I was surprised the Mullard 10M tubes were not the best fit:

GE 5-Star TRIPLE-MECA 5751 BLACKPLATES (second place to the Teles)

Mullard 10M Master Series Gold Pin 12AX7

New Stock Tung-Sol 12AX7


I am also trying a NOS RCA Branded Philco 5U4G

My RCA 5814A has just failed (after a couple of days), back to my RCA Blackplate 12au7.

Did you ever try a NOS Telefunken 12au7?

It is very good (the Mullard 10M did not sound right in the phono preamp}

It seems tubes in the RIAA portion of the ZP3 have a dramatic impact on the sound (more than any other tube rolling that I have been involved in).

I might try the Sylvania 5751, but in my system the lower output of the 5751 tube does not sound as good as the 12ax7 (the 5751 allows for more background noise, the 12ax7 approach dead silence).

I have experienced a problem with some tubes that create hum at around 1000 hz and below, I wonder if this characteristic  is considered a noisy tube or just a tube that creates hum.  

The next tubes I will try will be Platinum Grade.

Peter,  Have you read "Joe's Tube Lore".  I'll give the link below.  As you read, remember that he was probably using a different pre amp and gear than you.  Also his tastes may be different than your's. So don't exclude a tube solely because he didn't like or list it. With those caveats, I've found his post from the late 90's to be very helpful.  Unfortunately,  I also think his views have been partly responsible for many of his favored tubes dramatically increasing in cost since he revealed his lists.

I went back and read what he said about Telfunken and Mullard 12AU7 type tubes...I copied it below.  This is why I haven't tried one.  I have tried a Mullard CV 4003 from Upscale Audio...I liked it, just not better than my favorite Black Plate types made by RCA. It's worth reading his lengthy thread.  Mark.

"Now shifting back to the present, the only other comments I might add relate to the obvious "what about the Mullard rib plates & legendary Telefunkens?" question. Well frankly there wasn't much to say. IMHO these are two of the most overrated brands in the NOS universe. generally speaking all the Telefunken 12A family tubes I've heard ('X7s, 'T7s, 'U7s) are a bit bright, thin and airy sounding. I've talked to Charlie Kittleson at Vacuum Tube Valley about this and he basically agreed, observing that these guys more or less built their reputation on their use by the old gear crowd. Why? Well his comment was that the caps, resistors & transformers in old gear were dark sounding sludge and the Teles offered a useful brightening of the sound to a more natural balance. The issue, of course, is that when you put them in a contemporary design with much wider bandwidth and a more neutral '90s kind of balance things can go over the top.

Now before any Tele lovers who find them ideal in their new gear freak out and tell me how wonderful they sound - I believe it. There is a system out there somewhere that's the ideal match for any tube. This is just a comment on a general tendency. Now Mullards are another matter. I have found a few that sound quite nice and they generally are warmer than Teles, but in my rig they never quite make it to the top of the heap."

http://www.audioasylum.com/scripts/d.pl?audio/faq/joes-tubes.html

Mark,

I made a mistake in my post.

My ZP3 is using a pair of NOS ribbed plates "12AX7" tubes with good results.

The 12AU7 tube is a RCA NOS (a $20.00 tube), again with good results.

My preamp is an Aesthetix Calypso Signature, I am using the GE 5751 blackplate triple mica tubes in the 12AX7 slot and Amperex SQ 6922 tubes.

My tweeter amp is a Mini Torii using a pair Amperex 7316 Holland Ct1-delta 9C in the 12AU7 slot and new production Valve Art 350B in the 6V6GT slot.

Peter, you don't have to try a GE Blk Pl Triple Mica 5814A...I just bought two for $35 including S&H.  I suspect they'll be similar to the RCAs, which would be good because they are much cheaper.  I'll let you know how they sound.  Mark.

It looks like at the end of my testing it is NOS 12ax7 Teles at both the first 12az7 slot and the second 12ax7 slot.

My Current Favorites (after a lot of tube rolling):

12ax7 (first slot from front, input tube): NOS Baldwin shiny blackplate made by Ratheyon (organ tube) from Brent Jessee for $50.00.

New Old Stock in whiteboxes. These are the genuine 1950s vintage Raytheon shiny blackplates. For a short time we have a very limited special LOW PRICE on these rare tubes made for organs, some OEM repair stock with no labels. Nothing like these are likely to ever be made again, and these have the added advantage of being factory screened for use in organ audio circuits. These beauties rival the vintage European 12AX7s, and are the best bang for the buck going in a vintage USA made.



12ax7 (middle tube or second from front, for RIAA curve): NOS Telefunken from my stash



12au7 (third from front, tube buffer): NOS Mazda (French) Grey Plate (1960's) from Brent Jessee for $80.00

New old stock, original and white Box. Grey plates, very similar to the very rare Mazda silver plate tubes. These are also hard to find in the USA. Excellent, 1960s vintage long lived 12AU7 types with the distinct European vintage flavor that a modern tube just cannot capture! These have the sweetness and dynamic punch typical of Mazda

lol, I`ve got 45mins left to run on a bid for a 1965 Mullard 12ax7  for that no1 slot on the ZP3. Highest bid at the moment (£18) and I`ll go a little more. So I could give some comments this evening.

oops, getting a bit carried away. It`ll be a few days ......delivery times.

In the past I've used a Mullard in all three spots, all pulled from my '59 EICO HF81. These tubes have lots of use and are probably not at their best. The sound was far too thick and rich with these in place, great for some ops but in general not the best fit. I've been using Raytheons in all positions with great success. Steve sent one with the amp and I bought two others from tgarden.

My final tube selection for the ZP3 (after way too much tube rolling, i have now gone "Cold Turkey").

12ax7 Tube Input (front spot): NOS RAYTHEON BLACKPLATE ORGAN STOCK-BALDWIN ($50.00 from Brent Jessee)

12ax7 Tube RIAA (middle spot): NOS Telefunken (from stash)

12au7 Tube Buffer (Third spot, closest to the back (transformer): NOS  MAZDA 1960'S (From Brent Jessee).


Brent Jessee is a pleasure to deal with, he allowed me to try various tubes until I found the best, Hammond and the Mazda are amazing tubes

Brent provides a 30 day return privileged on Tubes!!!!!!!

Also I upgraded to a NOS RCA 5U4G Coke Bottle (Brent Jessee) and a Green Label on Base Coke Bottle Sylvania NOS OA3 (upgrade for OA3 from Decware).

Mazda 12au7 info;

New old stock, original and white Box. Grey plates, very similar to the very rare Mazda silver plate tubes. These are also hard to find in the USA. Excellent, 1960s vintage long lived 12AU7 types with the distinct European vintage flavor that a modern tube just cannot capture! These have the sweetness and dynamic punch typical of Mazda.

A lot of good tube options here, so thank you all.  My ZP3 will be arriving in 2-3 weeks. I've ordered from B-Jessee nos 12AU7 cleartop rca rebranded for Conn organ & nos 5Y3GT 50's rca.  Gonna let ZP3 cook for 2 or 3 weeks before I roll in nos tubes. I also have some 0A3 RCA 1951' to try as well as some rectifiers bought for my superzen that I will experiment with as well.  Will let everyone know my findings/ liking's once this long process is finished....ahh now I need some patience!

I substituted a NOS Mazda in my second 12ax7 slot and tried it for a couple weeks.  A couple of my hard core blues buddies came over the other night and we spent a few hrs listening to Junior Kimbrough and Lightning Hopkins.  They thought it sounded it great but i wasn't too happy except for the Whistlepig rye they brought.  I put my NOS Mullard back in and boy am I happy.  IMO the ZP3 and tube burn in make a huge sonic difference, much more evident than in my CSP2+ or Torii III.   I find a matched pair in the 12ax7 slots really makes a difference. It takes time but wow when you find some tube synergy it is breathtaking.

JD

JD

I've found that an RCA 5814A in the 12AU7 spot is by far my favorite. Vocals become real and in the room.

Nice tubes.  Those Raytheon black plates were the first NOS 12AX7s I had in my ZP3...they sound very good as do anything RCA Black Plate.  I use a pair of the raytheons in both my Jolida 100 CDPs.  I've never tried a 5U4G in the ZP3. But have them in both Amps.  Mark.

Greg, I just read this thread again and I've outlined my experience in the past.  I roll the 12AX7 spot every 1 or 2 months but the 12AU7 spot hasn't changed since at least June.  So currently I'm still using the RCA Triple Mica Black plate 5814 and have 4 more in the mail bought cheaply on ebay.  In the 12AX7 spot I've been running for the past month a pair of Military Sylvania triple mica, black plate, steel pinned, 5751s.  This is my favorite combo so far. But the gain with the 5751 is 70% of the 12AX7s so this may be a problem with your cartridge since it's a MC used without a SUT.   Mark.

PS...I think for a change, I'll leave the 12AX7 spots alone and roll the 12AU7.  After reading what others liked, I'm going to try a Mazda 12AU7 and a Mullard CV4003 in that position. I've got a couple of each somewhere.

I can't remember who I bought them from but they were originally from Upscale Audio...the links below describe them at Kevin's site...

http://www.upscaleaudio.com/mullard-cv4003-12au7-vintage-new-old-stock/
http://www.upscaleaudio.com/cifte-12au7/

Greg,  you shouldn't feel the need to try the 5751's, they are all expensive especially the triple micas...but if you can't resist, the GE Black Plate triple mica 5751's are cheaper than RCA and Sylvania entries.  You also can save at least half of what Brent Jesse charges by using ebay. I really think your choice of the raytheon and RCA black plates is excellent and if you were to stop there you wouldn't be missing much.  Mark.

Theres no need to go for 12ax7 pairs really as they do different jobs. The more singles you pick up can be swapped around. I look for different getters as well. The ones in my ZP3 have a disc with a punched indentation. They are a pair though as I liked the first one, so because they were cheap got another.
Syd

51' RCA  0A3 bottle shape
mullard 12ax7 cryo'd (new) input and output spots
Buffer 3rd spot  RCA cleartop 12au7 -side getter,  
rect: 50's RCA 5U4GB black plate straight bottle - tall.  

To roll in I have:

Sylvania 7025 / 12AX7  60's
the pair tungsols that came with it 12ax7
RCA  50's   5Y3GT
Valve Art 274B that came with it
Philips  5R4GYS
Svetlana =C=  5U4G/5C3S  bottle shape  70's
the 12au7 that came with it (mfg ?)
RCA  50's  black plate 12au7
Sylvania  03A
Sylvania  0CA
A few other

These are my dream team
they`re back together and they`re bad ass

1. `65 Mullard 12ax7
2. `50`s Syl x3 mica 12ax7
3. `56 Philips Miniwat 12au7

`50`s black plate RCA JAN 5R4GY 1x sq getter
Eng Electric 0a3

I tried a Cossor 12AT7 in the AU7 spot Mark and one of my Webcor 12AX7`s blew. Ok, Webcors aren`t that great but I wont be using the AT7 again.

I used to say I disliked all the hardware aspect of Audio...trying and reading about gear, speaker cables, etc....preferring to just sit back and listen to the music without considering all the details needed to get there.  This is still largely true.  My recent interconnect and speaker cable experimentation is like pulling teeth...not something I find enjoyable.  And as a result it's taking me forever to come to conclusions.

But I have come to the conclusion that I do enjoy tube rolling. I enjoy reading about the history of tubes and getting into the art of reading date codes and examining the internal structure of tubes to reveal who actually made a specific tube...and finally I really like the result of changing a tube.

I mainly have been tube rolling in my ZP3 but have recently also been trying more input tubes in the CSP3 and Zen Signature Monoblocks.  The newest ebay purchase last night was an Amperex Bugle Boy 1959 I61 12AX7...as well as another Amperex BB 6DJ8, I already have one pair.  Mark.

Lon,  you are talking about Decware Studio Grade interconnects (DSGs) correct?  Have you tried the Decware Silver Reference interconnects, if so, what were your impressions.  I had not considered the DSR interconnects the cause of some of my high end problem but after my experiences with different speaker cables and interconnects in my main system...I'm starting to wonder.

I am interested in interconnects you want to sell as well as other gear.  In home trials would be great. I thought you were currently using some ultra expensive interconnects...are they cooper and silver?  Anyway, I'm open to all suggestions and help.  I am looking forward to a time when I'm content with my cabling and can just enjoy the occasional tube roll to keep it fresh.  Thanks,  Mark.  

PS...after reading your post again...you moved away from the decware silver interconnects, correct?

Lon,  now that you are in ZP3 tube rolling mode I thought I'd bring up this thread that has tons of info, impressions and ideas.  Also the link below is a more recent thread that may be helpful...I haven't re-read any of these yet but probably will. And of course there are numerous tube impressions scattered through other threads.  I am constantly talking about tubes tried in the "What's Spinning" thread as you well know. Mark.

https://www.decware.com/cgi-bin/yabb22/YaBB.pl?num=1359652300

https://www.decware.com/cgi-bin/yabb22/YaBB.pl?num=1402147415

Lon wrote..."I find everyone else's impressions of tubes in a component an interesting guide but in truth I think tubes sound differently in each system and room and it's hard to make definitive choices."

Lon, I agree 100% but still I find other's opinions a good starting point.  I found Joe's tube lore very helpful when I started my tube rolling.

http://www.audioasylum.com/scripts/d.pl?audio/faq/joes-tubes.html

But I must admit Joe's opinions of Telfunkens and German tubes in general have kept me from trying them.  Which is OK since usually they are much more expensive than those I've tried.  I may have to try some since you and many others have gushed about the Telfunkens in the ZP3 and Decware amps and preamps. Anyway, keep us apprised of your tube rolling adventure. Mark.

That would be a mint name "Prone to Preconception" for an album or even a band.
Looking forward to a special celebrating MLK jr. on the radio program American Routes at noon today.

JD

JD wrote on 01/17/16 at 15:41:42:

That's nice Justin. MLK was one of the greats.

One of the true great humans for sure. Mark I listen on 91.9 fm here in Boston but I know it is broadcast nationally.  I never miss it, the host is a great resource for knowledge and music. That is followed by a world music program and then a few hours of Celtic music...my sunday ritual with football on mute playing on the tv.

Happy Listening

JD

Lon,  your gravitation toward the cryoed TAD 12AX7 and 12AU7 has peaked my interest...I may order some as well as a cryoed Valve Art 274B.  Mark.

I like these cryo'd tubes for the ZP3. . . they took a bit of time to "cook" or burn in but when they bloom they're very nice and accurate but not harsh or sibilant.

Ok I have to admit, I haven't been playing vinyl because It just wasn't sounding as good as my other sources. You guys motivated me to investigate. So, just took off my platter, belt and  reattached everything because I saw that although my table was dead flat the subplatter was not and it is just too flimsy. I am totally getting the subplatter upgrade for my p6. For some reason Herbie's isocups and balls isolate sterilize the sound and I don't like em under my table.
Tube rolling: I just replaced my front 1963 mazda 12ax7 with an RCA black plate 5751 that I completely forget buying. In the second spot is tele 1959 ribbed plate that plays nicely with others and early 60's mazda in the 12au7 spot.  
Totally got rid of the bass bloat that was just ruining my listening pleasure because i'm just not a big bass guy. I like slam but loose bass drives me nuts.
Took my 3 hours of listening to side 3 and 4 of Robert Plant and Allison Krauss Raising Sand album but aah...success. Good album for me to test cuz although their lyrics are sublime the bass is up front and really strong against their vocal arrangements.
After shoveling for a couple hours time to relax.

JD

Great news Justin! You'll love the sub-platter and what it does. It's a work of art, and the one thing I don't like about the Delrin platter is that you can't see the sub-platter when it's on as you can with the stock Rega platter.

Interesting that you note the Herbie's turntable balls and Iso-Cups are making the sound sterile, I wasted some money on those recently and agree, they do have an appealing liveliness to the dynamics and high end on my system (on top of the PowerBase) but the sound is thinner than I can stand.

My gal is back from her Saturday night sleepover so we're doing other things and I'm not spinning vinyl. I so enjoyed about 15 hours of listening this weekend. And now it's my turn to start shoveling, have about 7" in the driveway since I shoveled yesterday afternoon!

I agree Archie and even though it's never part of the plan trouble shooting with all this gear does help with problem solving skills. It's cool that there are so many different paths to finding, fixing and enhancing the listening experience.

JD

Well, I did some more rolling and I'm going to stop for now with this complement:

Siemens 12AU7
Amperex Bugleboy 12AX7 middle position
Amperex Orange pring 12AX7 front position

Okay, I went back to the Siemens and now I'm alternating with an Amperex 12AU7 . . . I like aspects of both, and there's a cool factor having all Amperex . . . but the Siemens has an endearing warmth that is missed by any other tube and really helps a lot of the material to shine.

been driving myself crazy because something was not right with the vinyl rig. forgot that i had put in a crappy mid 80's rca 5751 in the front 12ax7 as an experiment...dont bother. Went back to my early 60's 12ax7 Mazda Cifte pair beautiful sound just right combination of sparkle and air.
celebrating with Thad Jones on blue note...delicious

JD

Folks, I'm working on an Amperex "Electronics For Medicine" 1968 12AX7.  Anyone tried one?  I would think that it's identical to a well matched 1968 orange globe 12AX7.  I've tried 1959 and 1961 that are different change code versions...this is I65.  Really not sure what it's worth but tube dealers seem to think they are Gold...at least they price them that way. Any comment would be appreciated. Mark.

Hello all,

Got some NOS NIB tubes as follows for the ZP3.

RCA mid 60's 12AX7A for the first two positions.

Brimar, mid 60's NOS NIB cryoed CV4003 for the 12AU7 position.

Holy Shit Batman !     What else can I say ?

These tubes, in the ZP3, I'm done and happy.

this is music, pure and simple.

Try these tubes, I can't imagine anyone being disappointed.

Cheers,                       Crazy Bill

After being pleased with a Tungsram 12AU7 I`ve gone all in and ordered a pair of Tungsram 12AX7`s. They have a red code on them as well,  and  M2  dating them from `65. NOS in boxes.
Most I`ve ever paid for signal tubes @ $169 the pair.
I`ll write back on how they perform.

It looks like Syd tried a 12AT7 in his 12AU7 spot and it blew one of the 12AX7 tubes. He wasn't sure if it was directly related, or a cause. Has anyone else given this a shot? It seems at some point the 12AT7 was listed by Steve as a sub...

I’m resurrecting this thread. Now that I have an acceptable TT and cart, I’m to the point that I want to get more serious about tube selection. I’m very happy with the NOS RCA 5Y3GT rectifier.

What about the voltage regulator and V1-3?

Thanks in advance!

Geno

I was looking for 12AU7 advice for the ZP3 and based on early posts in this old thread I bought what looks like a NOS triple mica RCA 5814A.  A bit of an unknown quantity but for $17 I figured worth the risk.  I'll post again if it makes an impression.

I’ve been extremely happy with two Telefunken 12AX7 tubes in the ZP3. Ive had a NOS Mullard 12ax7 and decided to put it in the first spot. Maybe I just needed a change but it sounded alive. It seemed to have a little more presence and shimmer. For lack of a better description... the tube magic I’m always chasing. Don’t get me wrong... the Telefunkens are great, but I might be a Mullard man. I’m going to  find one for the second spot.
I’m wondering.... when tube rolling, what’s the protocol for turning on and off and wait times? How long should I leave the amp on once I turn it on (does that even matter?) once I get into tube rolling mode, I like to swap fast and go back and fourth but don’t want to damage the amp or tubes.

Thanks to everyone who posted here - very helpful thread for getting the best out of the ZP3. Restarting this thread to share the combo I landed on after a reasonable amount of tube rolling:

Rectifier - 50s RCA 5Y3GT

Voltage regulator - Tungsram OA3 (tighter bass, better presence, clearer mids)

12AU7 buffer - 60s UK Brimar CV4003/12AU7 (bigger soundstage, more texture throughout, tighter bass)

12AX7s - 60s US Raytheon/Baldwin black plate 12AX7A in both positions (balanced overall with clear & detailed midrange)

This combo works super well together. The Raytheon/Baldwin 12AX7As are a seriously underrated tube that is still economical for NOS matched pairs (~$60 total). It makes sense this tube would work well since organ tubes are designed to be very quiet and cover the full frequency spectrum. I also tried a 50s GE 5751WA triple mica black plate, but I personally didn’t like the decreased gain. Planning to also try a type 80 rectifier after I’ve had great results in my SE84UFO.

I’ve found an excellent tube for the middle position of the ZP3 from the guitar world - the Sovtek 12AX7 LPS. This is a very neutral and clear sounding tube with full extension at both ends. It is often used in the phase inverter position of a guitar amp due to its very balanced and clear sound and can be purchased for around $20. I also tried a pair in the front and middle positions, but this was a little dry and lacked character, although extremely clear and clean sounding.

The front tube is definitely the most influential tube in the ZP3, but a wide spectrum, neutral, almost “dry” tube seems necessary for the second position in order to properly tailor the sound using the front tube. I’m now using a Raytheon/Baldwin 12AX7a in the front position, sovtek in the middle, and 1960s French Mazda 12AU7 in the 3rd spot. The combo is pretty killer! By far the best of my extensive tube rolling and extremely dynamic

Surfer-

Read through this thread, starting at reply #8, and the next few responses following. Also, use the edit function of your browser (if it has one), 'find in page' and enter 5751, for each page in the thread. Several comments and observations on using that tube in the 12AX7 spot.

PS

What kind of music do you listen to?

Your calculations seem about right given that my 0.35mV cart with a 20X step up and the ZP3 is about 1 volt.

I don't see why you are concerned.  After leaving my ZP3 at 1 volt I further step it up with the CSP3 to over 10 volts.  I then squeeze it down with my ZMA which hits maximum power at 2 volts.  The extra input voltage adds weight to the music.  Riding the gain.

What do you think the downside of the extra gain is?  My experience is that more gain will result in more volume for the same knob position.  With 1 volt input, most of the Decware amps won't be able to reach full power/volume.  And of course, if input exceeds the amp spec for full volume, the input is attenuated by the amp volume knob.

But I may not understand your issue.  I've always thought the ZP3 would benefit from more gain but after reading Steve's White Paper on the development, I think he was happy to get what he got without noise.

Two questions to ask in these situations are: what is worst case? Which is not informative by itself, so we ask: for what duration?

Through much reading of data provided by Sure Bros. and others, at 1,000Hz the absolute limit in vinyl cutting is 35 cm/s. Reading further, the max found through measuring of many records was ~ 28-30 cm/s, at some place on two records (of many samples). Aside those two, the highest were ~ 12 and 15 cm/s. For a cart output measuring.0005 V (.5 mV) @ 5 cm/s-1,000 Hz, 30 cm/s is 6x and 15 cm/s is 3x above test spec. From an article I dug out from Stereo Review printed in 1968, the writer said that few records have anything much above 15 cm/s. So I have taken for myself that 4x the test record spec is the R/L actual worst case that we should have any concern about.

With a cart of .5mV going into a 20x SUT and a 125x (42 dB) phono pre, that comes to 5V. Worst case.

The second question is duration of the event. Look at the data on this page: https://www.dpamicrophones.com/mic-university/acoustical-characteristics-of-musi...

The attack duration of snare drum measured 5-8ms, bass drum:8-12 ms, tympani (all sizes): 10-18 ms, trumpet: 20-40 ms. These are the loudest instruments in the orchestra. 20 ms is 1/50 of a second. That would be nigh impossible to attract perceptual notice, for one, and I don't think it would trouble even a SS preamp input stage overly much. I don't know for certain, but I don't think even 50 ms (1/20th second) would cause too much trouble, but who knows.

So then with your cart and SUT, we have "an extraordinary vinyl event" resulting in 5 volts output of a 42dB phomo preamp for 5-40 milliseconds.

After all that, your own experience is the final determinant. If you notice distortion when you set the phono preamp higher than 40 dB, then there it lies. But that might or might not occur with another phono pre, SS or tube.

I don't think you need to stress much over it because it might be fine with the ZP3 as is, and if not you have the option of replacing the 12AX7 tubes with the 5751 set.

Edsonic is lightyears ahead of me in his understanding of all of this but this quote stands out:

Quote:


All of the analysis aside, you say you get distortion above your 40dB.  Is it in your existing phono pre?  My NAD pre has both MM and MC inputs but the MC is crap.  (I don't use this anymore though.)

More things I am ignorant about.  I assumed that anything with a "volume" knob would attenuate the input signal down to zero.  There must be a knob on his amp otherwise it'd play at full volume always.  What am I missing?

Hi guys, I appreciate all of the helpful information and feedback.

I now believe the main culprit of the issue I am hearing is what Edsonic mentioned - "extraordinary vinyl events"

My integrated amp and/or phono preamp is not properly handling the "extraordinary vinyl events" that my 20x SUT and 0.5mv cartridge and phono preamp are producing. Events lasting only in milliseconds with output ranging from 2 to 5 volts.

I have two technical follow up questions I hope you don't mind answering-

1. Do you think the maximum input capacity of the ZP3 increases when using the lower mu 5751 tubes? Edsonic - I read one of your other posts where you thought the ZP3 should have at least a maximum input capacity greater than 100mv. Will the use of 5751 tubes increase this maximum capacity number?

2. Edsonic - your calculated db decrease of the 5751 compared to using the 12ax7 was Log(70/100) x 20 = -3dB. Does your calculation encompass the use of 5751 in both v1 and v2 slots? Or is using 5751 tubes in both v1 and v2 slots additive to the drop in db? [Log(70/100) x 20 + Log(70/100) x 20] = -6.19 db for an overall output of around +36db?

thanks for your help

Surfer-

Refresh page and make sure you read the last few items Archie and I talked about. We all might have been typing at the same time.

To your first question above- I can't say for certain. I just know the basics about tubes so I don't think I'm qualified to answer that definitively. I know that 12AX7 tubes overload easier than tubes with less gain, generally speaking. In any case I don't think any cutting levels are above ~ 52-55 cm/s, that occurring at 8kHz-9 kHz. I don't know how to mathematically translate cartridge output from 5cm/s @ 1,000 Hz to other frequencies.

Have a look at this:http://pspatialaudio.com/max_velo.htm Scroll to the chart halfway down the page, past the graph.

My guess about the ZP3 input limit was based on a 'search survey' which brought up several SS phono preamps with 70-120 mV limits and an AR and Manley Chinook w/ 240 mV limits. My estimation of at least 100mV for the ZP3 is probably a low ball figure. That said, there are a number of phono preamps with 40-60 mV limits.

To your question about 2 tubes / 2x the dB calculation, I'm not sure about that either. Standalone, it makes sense, but the circuit might have it otherwise.

Edsonic and Archie,

I appreciate the knowledge you have shared with me. I definitely have a better understanding of how much voltage my phono preamp and integrated amp are experiencing even if for a few milliseconds.

When my ZP3 arrives later this year I will be sure to add my experience of how well a ZP3 with various tube compliments works with a 0.5mv cartridge and 20x SUT.

and fyi - my integrated amp does not have an input attenuator, only a volume knob

And in the meantime, if anyone knows if swapping the two 12ax7 tubes for 5751 tubes theoretically reduces the gain by 3db or 6db, please do not hesitate to respond:)

Thanks again

A few things I overlooked in prior discussion.

Surf, I think the reason your SUT sounds better @ 20x setting is because the cart DCR is so low. (Generally speaking, lower cart DCR is a good thing). The SUT steps down the input impedance of the phono preamp by the square of the  turns ratio. So from the 47kΩ input of the phono pre  a 10x ratio would present 470Ω to the cartridge, 20x ratio would make it 117Ω (47k/400). With a cart DCR of 1.4 the second number is a much better fit.

Regarding the gain situation, I think it might be best to have the ZP3 operating as intended to the extent possible. To that end using an in-line attenuator between the phono pre  and the integrated might be just the ticket. (I knew there was something kicking me in the back of the head before, that was it). Here are some from Parts Express -

https://www.parts-express.com/home-a-v/audio-video-accessories/line-level-attenu...

They are cheap enough that you could get both the 3dB and 6dB pairs. I searched around a few years ago and these seem to be well regarded. They should be plugged into the 'line in' / 'aux' of the integrated to keep the signal strong till the end, for better signal vs. EMI/RFI on the cables. That last item is another reason the attenuator pair  might be a better solution than lowering the signal output of the ZP3 by use of lower gain tubes.

If you still want to try the 5751 somewhere I think it should only be after the RIAA section. (Another thing I forgot about). The front tube of the ZP3 is where the signal comes in first. Using the 5751 there would  provide less gain to a weak signal then going through the however slight noise of the resistors and capacitors of the RIAA filter. So then worse signal-to-noise ratio at the worst place.

I think using the 5751 tube in the second slot, after the RIAA, should be okay, in the process obviating the need for our question about dB using two 5751s. If you eventually get into tube rolling you might pay the extra money (for the front tube) to get 12AX7s that are tested for low noise. Vintage Tube Services and Brent Jessee Recording & Supply do that, there might be others.  

Hi guys,

Hope all is well and happy New Year!

While I am only a few months away from receiving my ZP3, I just wanted to share a few updates.

Although I still think my current phono preamp is experiencing voltage spikes beyond what it is capable of handling, I discovered the primary problem…..my integrated amp's DC bias was measuring far above required specs. (About 200% above spec!)

Once I turned down the DC bias to the specified level found in the service manual, a lot of the issues I was having with my vinyl rig playback went away.

So, I am happy to say I will probably not be needing any type of attenuation in the way of in-line attenuators nor lower output tubes.

Once I have spent sufficient time with the ZP3 and done some tube rolling, I will report back here

Cheers

After some reading I went way way way down the wrong road all the while convinced it was correct. .5mv cart on 1:20 = 10mv!!! No wonder things were too loud. 1:10 is a better setting at 5mv. The volume knob now gives me the range I was used to. I removed the 5751 from the first spot and things became even better. I really love the smoothness and openness of the 5751's but I really think the .70 output from them limits the overall performance.

I didn't care for the Sovtek red tip 12AX7LPS. Bit too sharp for my tastes. Settled on the following:
1 - Mullard 12AX7
2 - RCA 12AX7A
3 - Gold Lion 12AU7

Now that the 5751's are out, I have to go back and try those 5184a's in the 12AU7 spot. If anything is missing, it's on the low end.

Hi everyone and hope all is well!

I have spent several months with the ZP3 and feel like I can now offer some personal feedback which hopefully someone will find useful.

I am extremely happy with the ZP3 and its numerous tube rolling possibilities which can change the sound to your optimal preference for not only different music genres, but for each album, and I could go as far to say each song if not for needing to change the tubes too frequently.

I think it would be best to disclose my current set up first, which is a mix of budget components from the 70’s and more esoteric Japanese and European components which were all purchased in the used market:

Receiver – Sony STR-V4 (55 wpc)
Speakers – KLH Model 23 – (around 87 db per watt sensitivity)
Turntable - VPI Prime Scout
Phono Preamp – Decware ZP3
Step Up Transformer – Music First Audio SUT V1 Copper - 5X, 10X, or 20X turns ratios – 1.3 ohm impedance of primary coil measured at 1 khz
MC Cartridge – My Sonic Lab Gold Signature – 1.4 ohm DCR

**The 1.4 ohm DCR of the MC cartridge and 1.3 ohm impedance of the primary coil of the SUT is almost a perfect match, which allows for maximum performance across the widest range of frequencies – common knowledge is that you must pair an MC cartridge/SUT based on optimal voltage gain and on optimal loading, but the not discussed critically important X-Factor for ultimate cartridge/SUT pairing is the proper matching of the internal impedance of the cartridge and the SUT’s primary coil impedance. The Japanese tend to adhere to this X-Factor much more than their American and European counterparts**

My previous phono preamp was a Musical Surroundings Nova set at +40 db of gain. This solid state phono preamp is a great phono preamp I can highly recommend with very tight and deep bass and quite a deal on the used market for around $500 USD.

With the ZP3’s higher gain of around +42 to +43 db, I did have to decrease the gain of my Music First SUT from my usual 20X down to 10X. The resulting gain going into the ZP3 was decreased to 5mv from 10mv.

I would say that the overall performance gain with my SUT set at 10X with the ZP3 with stock tubes was a +20% increase in performance compared to my SUT at 20X with the Musical Surroundings Nova.

In the world of high-end audio we all know an increase in performance of 20% is huge and could potentially cost a large amount of money, so I was extremely happy with the ZP3 and the long wait was well worth it.

But…..there was some magic I was accustomed to hearing missing from some familiar tracks……

Because of the KLH speakers lower sensitivity of 87 db, they really need a lot of voltage to make them sing and on a few songs when I was able to increase my SUT to 20X going into the ZP3, the sound was out of this world – like technicolor rainbows of beautiful sounds pouring into the room and over your body like a lucid dream….yes, I know this description is over the top, but this is the best way I can explain what I was hearing with my SUT set at 20X. I felt like the tubes in the ZP3 were thanking me and were completely able to run free without any limitations producing ultra-vivid and dynamic music without boundaries….

But, with the ZP3 and stock tube configuration I could only turn up my SUT to 20X on a few tracks that were already cut quiet….

This is the point when I started experimenting with NOS tubes. I thought placing a 5751 in the V1 spot might tame the gain enough to allow for me to turn up my SUT to 20X, but it wasn’t. I kept having to turn down the gain to 10X for some songs to play without excessive gain.

I then tried a 5751 in the V1 spot and a 5751 in the V2 spot. This combination did not work well at all. It sounded as if 20% of the life of the music had been sucked out of the room.

I then tried an even lower gain 12AT7 in the V1 position and 12AX7 in the V2 position with my SUT set at 20X…….Voila!!! technicolor daydreams were pouring out of my speakers and the sound was nothing short of a religious experience. ….I know, another over the top description, but this is how I felt on an emotional level.

Another increase in performance was had by replacing the 0A3 voltage regulator tube with an 0D3 voltage regulator tube. The best way I can describe the improvement in sound was that the 0D3 was giving much more space in the sound stage from back to front and side to side for the music to flow. I think this was because of the extreme dynamics being produced by the My Sonic Lab cartridge and SUT at 20X combination needed this extra breathing space to run at their optimally combined musical speed.

At this point, I thought to myself that the performance of the ZP3 is now 100% - 300% + better than my previous phono preamp - the Musical Surroundings Nova - depending on the album being played.

But…. I have noticed that a few rock & roll tracks that were cut really hot are pushing the limits of gain and I have ordered some 12AY7 tubes to put in the V1 spot to see if this will do the same trick as the 12AT7 did with most of the music I play.

Special note – after reading Sean’s previous posts and seeing that he is using Tekton Pendragons speakers with a 98 db per watt sensitivity – I think the reason I can run my SUT at 20X with the My Sonic Lab’s 0.5mv output for a resulting gain of 10mv is primarily because of the KLH speakers being less efficient and only having an 87 db per watt sensitivity.