PCC88s vs 6922s

[Joe Appierto]

Sovtek and Electro-Harmonix are basically the same company. The older Sovtek were developed when the Soviet Union needed tubes for their military applications. Electro-Harmonix is the sibling company now owned by an American manufacturer/importer. Both are tough as nails and like the old Timex commercials will take a lickin' and keep on tickin'.

I've owned a bunch of 7DJ8/PCC88 tubes and only one group did develop noise. Tungsram. That was it and it was over 10 years ago. Haven't bought any since because I no longer need tubes.

[Big Dog RJ]

Great points there AJ & Joe, and definitely not pointed at anyone as I read AJ's last post.

It makes perfect sense that these tubes are basically quite similar, except for that 7DJ8, runs at a slightly higher voltage. Not sure why they use this in the GATS2 but the owner has switched back to the EH6922's and everything is humming perfectly!

Speaking of humming... I was enjoying some mighty fine tunes these past few days, until just now! Another Mullard M8080 bit the dust! It was the usual raspy paper tearing noise, followed by sputters setting off the LEDs on the output tubes. At this point the CLX also lit up, so I changed the little bugger and now all is well!

This is the last one Mullard, out of the batch of four I ordered in two pairs. I'm not sure if both pairs were from CJ but I remember that at least one pair of Mullards was from CJ as I still have the receipts. So, now just one is operating fine out of that batch.

On the other monoblock (left channel) I've replaced the Mullard with the original Mullards that came with the amplifiers over 7yrs ago. These tubes are still going strong! So basically something tells me that the batch of four I purchased (low noise, low microphonics, matched and tested, ladi-dadi-da...) what a load of bollocks!

Those original Mullards haven't skipped a beat (oops hope I didn't talk too soon) and now when I place another order for these M8080's I'm not sure what to look for, other than hope that they would last a year or two...

My local supplier also has other brands, such as Siemens and Ratheon, I might just give these a try until CJ's order arrives. BTW, I just got to know from our importer that the delay with my tube order was nothing to do with JF going fishing or anything of the sort. It turned out that they didn't place my order in the first place, so he kind of just remembered that he had forgotten to order my Mullards... !@#$

Oh well, I guess I'll have to rely more on our local supplier, as he seems to be a bit more customer focused...
I really don't understand how anyone can forget, especially after I've been chasing them with several phone calls and the answer was "it's on the way..." only to learn that the bloody order was never placed!

Apart from that, all else is mighty fine and now I'm listening to some blues from Eric Bibb on vinyl.
Cheers, and enjoy those fine tunes!
RJ

[Music Matters]

Hello everyone! I have an ET5 and here is my experience in last 7 years.

CJ supplied EH 6922 from new. Starting hissing in one channel after about 200 hours. Got replacement from CJ. Was same model: EH 6922. Exactly same happened after about 200 hours, so no luck reliability wise with EH6922.

Bought Genelex Gold Lion premium from tubestore. Lovely sound. Lush, detailed, dynamic initially. Much better sounding in my opinion than EH6922. After about 200 hours went very dull, lifeless, lost all dynamics. It didn't sound good.

Tubestore recommend Tungsram NOS 6922 to be more durable after discussing my issues. I got that and sounded exactly like tubestore said it would. Very neutral, tight leaner bass, not as warm, dynamic, great imaging. It sounded great. Great customer service from tubestore too.

I also bought some Matsushita PCC88 from Watford Valves from UK After a lengthy enjoyable chat for over 40 minutes with him giving me great customer service as well. After 494 hours I replaced the Tungsram with the Matsushita. The Tungsram was sounding superb still...no issues, I was just experimenting!

The Matsushita is at opposite end of spectrum to the Tungsram I would say. Fuller bass, more organic and laid back, it's probably more even across all frequencies than the Tungsram, which is a little leaner in the bass. Both are amazing valves...just very different presentations.

Matsushita has 400 hours on it and sounds amazing still. So I have had no success reliability wise with EH6922 or Genelex 6922, but great so far with Tungsram 6922 and Matsushita PCC88 in my ET5. The Genelex 6922 for first 100 or so hours was still probably my favourite sounding one...a pity not reliable in my preamp, but very happy with Tungsram and Matsushita which both sound better than EH6922, but very different to each other. Hope that helps!

[admin]

First, welcome to CJO. Great to have you with us Music Matters.

Those are some incredibly early failures, regardless of tube manufacturer. Any chance there was some underlying issue with the ET5?

[Music Matters]

Thank you for your welcome! I purchased my ET5 from CJ new and think it's fine...I said 7 years ago but I think was before that I bought it...maybe 10-12 years ago. In 2017 my sugden power amp blew a fuse and transistor, and I didn't know whether it was the pre or power so took both in to the technician to check, and the pre checked out perfect, it was the sugden power amp that needed repair. With Tungsram 6922, or Matsushita no issues with tubes, so either my ET5 is just a bit hard on the EH and Genelex 6922, or I had 3 bad tube samples. I think likely the former.

I love CJ gear. I started in about 1998. Have had pv10a, pv14l and now my ET5 preamp. My phono stage is the EV1 (it's been refreshed with new capacitors including some Teflon vcaps and better resistors), and whilst using a sugden power amp now, I used to own an mv55 and then a premier 11a...I regret selling the premier 11a sometimes...it was a really lovely amp! The sugden au41p is sweet in a different way.

Kind regards,

Graham

[AnotherJohnson]

I know that feeling of seller’s remorse.

But in my case it’s usually assuaged by the joy of new gear.

[Big Dog RJ]

G'day Graham,

That sounds about right. In fact I had very similar issues on several batches of EH & Genalex tubes that I bought. About 6 of them failed one after the other... and so now I don't use Genalex although I still have just one pair as spare. I'm now using the EH6922's for over a year and so far so good... hoping it should last a bit longer in my monoblocks.

Moving forwards, when I need to replace these tubes, I will change over to the Phillips 7DJ8 or Phillips Pcc88. It's a great reliable tube and delivers some very fine tunes! In fact JF himself highly recommends the Phillips, although it operates on a slightly higher voltage, in the range of 7V against 6V on the EH & Genalex tubes, CJ circuits that use this particular tube variant as either input gain or driver / phase inverter stages, actually run the voltages at 7V, so I was told by my trusted CJ tech... so he must be accurate.

I'm still getting fine tunes from these EH and Genalex tubes, so might as well use them as spares but Phillips will be my new preference in time to come.

The Matsushita tubes are great but these are all NOS based tubes. Matsushita stopped making tubes after the 60's & 70's, so any Matsushita you see are very old stock... if you find a Matsushita with new production dates embossed on them, I'm afraid these are not genuine! Like I said, very old stock going way back to the 60's production run. I would be careful of NOS tubes as they can go off anytime... like a time .
However, they do sound remarkable simply because they are NOS! I would recommend only new production tubes or anything reissued, they're made to higher tolerances and kept up to date. I wouldn't spend money on NOS.

That's just my opinion and 50cts worth but at the end the decision is yours. Enjoy those fine tunes!
Cheers, RJ

[WPG]

Graham,

I thought I would post my tube experience with my ET5 in case you get the urge to experiment some more with tubes.

I own an ET5 that I purchased slightly used in 2012 from a member on another forum. When I received the ET5, I never bothered to open it up to see what tube had been installed. It wasn’t until the end of 2021 when I had my one and only tube failure. I started to notice some slight distortion coming from my speakers. The ET5 had been in my system for almost 10 yrs without any problems and I figured changing the tube would be the best first step in troubleshooting. Luckily the ET5 is dealing with only one tube.

When I open up the ET5 I found a 6922 Westinghouse tube that was made in Germany. Visually I didn’t notice anything out of the ordinary however since the tube had thousands of hours on it, I decided to change out the tube.

I installed an EAT Cool Valve ECC88 Selected tube that I had purchased when I first got my ET5. The new tube took care of the distortion and greatly improved the sound stage and the overall sound quality; there were noticeable improvements in separation, clarity and details. At first the EAT was such a change from what I was used to with crisp details & clarity, my initial impression was that it made my system brighter and I found my system to be slightly fatiguing after several hours of listening with the volume level starting in the mid 50 dB range. After a hundred or so hours on the tube, it settled in, I got used to the changes and I no longer felt any fatigue after hours of listening.

After experiencing the improvements that the EAT made, I starting looking for another EAT for a back up. I was not able to find any EAT Cool Valve ECC88 available so I started researching the CJ forums and looking for NOS tubes with similar characteristics to the EAT.

After researching and checking the various tube supplier sites, I ended up contacting Brent Jesse at audiotubes.com. After talking with Brent, he recommended a NOS BEL/Philips/Amperex made in India in the 1960s. The tube was made at the Dutch Philips/Amperex owned Bharat Electronics Limited factory in India (BEL). I purchased the tube and also paid for Brent’s noise testing service so I would know the NOS tube was up to Brent’s standards before it was shipped.

I swapped out the EAT and I immediately noticed an improvement in the rhythm/percussion details in the music. As the BEL tube settled in I found the sound stage was slightly smaller than the EAT and it was a little warmer then the EAT. The BEL provided the details and overall sound quality that I was looking for. After several hundred hours on the BEL/Philips/Amperex I decided that I preferred the BEL over the EAT in my system and for the type of music I like to listen to; female vocals, classic rock, blues, Americana/country.

I contacted Brent again to talk about getting another 6922 tube to try in the ET5. I wanted to experiment some more and I figured if the new purchase was better, the BEL would be a great back up. After talking with Brent about what I liked about the BEL and providing him with more details about the music I prefer, he recommended a NOS 7308 Mullard UK made tube from the 1970s. Mullard made these tubes in the UK for the French Signal Corps. I purchased the Mullard along with the noise testing and I now have over 175 hours on this tube and I am extremely happy with how my system is sounding.

This tube will stay in my ET5 and I don’t have any urge to experiment with other tubes for the ET5. Since this tube will stay in my ET5 I decided to purchase the 2 year extended warranty that Brent offers. Brent guarantees his tubes for 30 days from date of shipment which gives you time to make sure that there are no immediate problems with the tube and it gives you time to break in the tube(s). Within the 30 day period you have the option to purchase a 2 year extended warranty on your tube(s). Hopefully I won’t need to use the warranty but it does give me some peace of mind.

[WPG]

Sorry to hear about all of the problems people are having with the Gold Lion tubes. The only Gold Lions I own were purchased back in 2012. It sounds like there may have been some quality control issues with Genalex through the years.

I don’t have any experience with the Genalex Gold Lion 6922 tubes in my ET5. I do own one Gold Lion tube that I purchased years ago when I got my ET5 but I have never installed it.

I recently swapped out 2 matched pairs of 12AX7 Genalex Gold Lion tubes that I had in my Zesto Andros PS1 phonostage since 2012. When I purchased the Zesto, the dealer recommended the Gold Lions so I purchased two sets of tubes; one to install and one for back up. The original Gold Lion tubes that I installed have held up for the past 10 yrs without any problems.

The 6922 Westinghouse tube that came with my ET5 finally failed after 10 yrs. Since I was experimenting with tube rolling in the ET5, I wanted to also experiment with the tubes in the Zesto. I swapped out the Gold Lions in the Zesto for matched pairs of NOS 12AX7 BEL/ Amperex tubes that were made in India. In my system, I prefer the BEL/Amperex tubes in my Zesto over the Gold Lions. Now I will just have to wait and see how long the BEL tubes will last.

[Music Matters]

Thanks all. No issues with gold lions 12ax7 in my EV1 phono stage...just the ET5 doesn't seem to like the eh 6922 or Gold Lion 6922 in my ET5, so I think it's a placement issue in an amp vs quality control in tube manufacturing. It's very happy with either the NOS red printed military spec Tungsram 6922 and NOS Matsushita 6922 in the ET5...both sound great, no issues yet, although I hear your concerns RJ, but all good for now and has been for a number of years. I also have the NOS Sovtek type 3 military spec 6922 which are meant to be very robust and supposed to sound better than eh6922, which are the type 2's...but haven't tried yet. Happy listening all!

Kind regards,

Graham

[Big Dog RJ]

Yes, sometimes NOS are fine and will last for years, even outlasting current production runs in certain cases.
However, my experience hasn't been too great, although the sound was excellent.

Similar to placing orders on some NOS Mullards years ago, three of them failed. Finally, I placed an order with Watford Valves and these are the ones playing now, hasn't missed a beat since. So I guess a lot of it is to do with batches, production runs and proper testing.

I must say though, in the past whiles using various tubes since the 80's, these sorts of issues weren't often but now it seems to be a recurring problem. I'm thinking that perhaps these are NOS starting to play up in 2021 & beyond... whi knows!

Anyway, I'm switching over to the Phillips brand for small signal tubes in time to come. As of now, EH & GGL's are operating fine, so might as well keep going until replacements are needed.

It's also after a certain period of trial and error just to stick with one, rather than tube roll/ change all the time. In the long run this will wear out the tube sockets and cause other issues... so I've stopped tube rolling as of now.

Cheers, RJ

[Music Matters]

Also just wanted to say thank you to WPG for your experience with your ET5...very thorough and interesting!...I will explore those suggestions.

Interesting that your Zesto phono has 12ax7 too and you like the BEl/Amperex more than GGL 12ax7. In my CJ EV1 I have had CJ valves (some Russian, some Chinese) that were ok, but best have been the GGL 12ax7, Sovtek 12ax7 LPs, and mullard 12ax7 reissue. They are all same design, long plate, same factory, but different sounding ..my findings identical to other reviews on websites. Mullard reissue is warmest, less emphasis on high frequency, but tremendous soundstage depth and image. The GGL have a more bright presentation with a flatter soundstage...and the Sovtek 12ax7 LPs split the difference and seem warm, excellent sound stage, but very even and we'll balanced across the range.

Not wishing to change this thread from PCC88 vs ECc88 to 12ax7...but was tied to earlier post, I think from RJ, that the EH 6922 and GGL 6922 are same factory but sound different...and I have noticed exactly the same in the 6922 and the 12ax7. Hope this is interesting you you all!

[roberto]

Just a little bit about the PCC88/7DJ8 vs 6922. The main difference is that the PCC88 has a voltage filament of 7.6V. The 6922 is 6.3 V. I will use the one that CJ recommend. The CJ power supply is made with a very precision design and stable voltage supplier. If you have a good voltage tester, just measure it and you will find of what I am talking about. There is no harm to use the PCC88 with less filament working voltage, but the tube is not operating with the maximum possible specs of what it is designed.

Tube life span is uncertain. We all tube users know that. I have in my system four 6922. At the beginning I used Philips Holland made 6922 and had good sound but they last 6 to 7 months only, then I got a hissing sound from my left channel. I was very curious why the left channel only got the failure, and I did not solve this. Then started my seek for a good sounding 6922. Did try a lot of different brands and ended with the Genalex EH6922 Gold Lion with gold pins. Many tube users don't believe that it is necessary to have gold pins. On the other hand, I love to see how clean and nice looking pins when are gold made. This kind of gold pins make me think that the pins are doing a great physical contact due to the fact that they do not get rusted. Rust means poor contact.

My system is well balanced from top to bottom, with a wide huge stage with a staggering sense of 3D. The voices are projected to the air with a incredible realism. The size of the musical instruments is right and also the timbre. The harmonic texture of the strings is amazing. The brass is enormous with tons of breathing air. The trumpet and the flugelhorn is like having them there, in my virtual stage. The sax is always a wow! The percussion is fantastic with the right dynamics on every stroke to the drums and cymbals. Detail, finesse, resolution, understanding what the left hand is doing vs the right hand on a piano, the plucking strings on a guitar,... the magic sound of CJ is breathtaking...

Happy listening!

[AnotherJohnson]

Just a little bit about the PCC88/7DJ8 vs 6922. The main difference is that the PCC88 has a voltage filament of 7.6V. The 6922 is 6.3 V. I will use the one that CJ recommend.

FWIW, when I started this thread, it was because CJ was supplying PCC88s in new units from the factory. I had three new units (ET3SE, ET7s1, and ET7s2), all with PCC88s rather than the specified 6922s. All three had failed within a year, were replaced by EH 6922s, and had no further issues during my ownership.

[roberto]

Hola AJ,
Sorry to highjack your thread a little bit.
Yes, that could be, but again the tube life span is uncertain. You had three bad tubes in a very small time of use. I had two in my preamp. Now I am using the EH Genalex gold pins 6922 with very good life span and excellent results. The quality sound is very nice, knowing that there are different sound presentation with other 6922 or substitutes tube brands.

Happy listening my dear friend!

[AnotherJohnson]

Yes, I think we both agree that the 6922s are the more satisfying choice for our interests. I was surprised to see the string of PCC88s from the factory, and of course disappointed in the elevation in the noise floor that occurred in the first few hundred hours of service.

[roberto]

Yes, of course, and you just pointed out the problem. The Genalex is a very good sounding and also has a good life span. And the noise is just fine for our needs. Now, all my 6922s are Genalex Gold Lion with gold pins. I do like a lot their sound presentation, knowing the there are many good brand's choices.

We had used a lot of double triodes and are very good and the 6922s are top grade and one the best. Easy available, and great span like. Also they brag, occupy, hold a good position in us, the tube users.

I have a signal to noise ratio meter. I can measure up to -110 dB using 0.775 V= OdB as voltage reference @ 1KHz tone. And with this 6922 tube, I measured the best signal to noise ratio of my ET-7. I am very satisfied with it.

Happy listening!

[WPG]

Graham,

When it came to rolling tubes in my system, I found the most noticeable improvements occurred when I changed the 6922 tube in ET5. The GGL tubes in the Zesto sounded good with the 6922 BEL/Amperex in ET5; however when I installed the NOS 12AX7 BEL/Amperex tubes in the Zesto, the improvements that occurred with the ET5 & 6922 BEL/Amperex tube were further enhanced on the analog side of my system.

I replaced the 6922 BEL/Amperex in the ET5 with a NOS 7308 Mullard UK made tube which is also working extremely well with the 12AX7 BEL tubes in the Zesto phono stage. I really like this combo and since changing the tubes in the ET5 & Zesto, the analog side of my system seems to be more quiet.

With the tube changes that I have made in both the ET5 & Zesto, I am finding the music is more compelling with a full rich sound with noticeable improvements in the sound stage, details & clarity; especially with acoustic/percussion/rhythm instruments.

For reference; my analog set up is a 30th Anniversary VPI Classic TT, Lyra Delos cartridge, Furutech Ag-12-R4 tone arm cable and the Zesto Andros PS1 phonostage; my digital source is an Oppo BDP-95, Schiit Audio Gungnir DAC, Morrow Audio digital cables.

[Music Matters]

Thanks WPG and much appreciated,

The site you gave where you got these valves was really interesting as I researched. The NOS 7308 Mullard is tempting... I like the Matushita PCc88 so far, and I read that these valves were made with Mullard machinery which is interesting. I think your Zesto likely outperforms my CJ EV1.. I haven't heard the Zesto but I've heard very good reviews. I know the Delos pretty well and have heard in a few different systems....it's a nice cartridge! My vinyl front end is an sme 20/2A with benz gullwing SHR..the 0.7 one as it fits well with gain on my EV1 (50db) and I think matches the series v sme well. I think my ET5 is a little hard on valves, which had also been documented by other ET5 owners on the internet, so good sounding durable options are appreciated. I think that is possibly why folks are recommending very durable 6992's for it, or pcc88's as they are more durable as possibly the ET5 runs higher than 6.3v or pushes the 6.3v envelope. I wonder if that's why CJ is supplying pcc88's with some of new amps as others have noted? Thanks for insight...much appreciated. Easter weekend coming so looking forward to listening to some vinyl!!!!

[Music Matters]

Just an update on tube longevity as I needed to replace the Matsushita 7dj8/pcc88 recently in my ET5. I keep track of listening hours. It lasted 500 hours and then sounded dull and lifeless.

So what I have so far in my ET5 which may help folks: (in order of use since I bought new many years ago).

Eh 6922 as supplied new and replacement by CJ years ago. Sound ok...only last 200 hours roughly. Used 3 sets of these and then...

Gold lion: sounded fantastic and lovely presentation top to bottom, lush, even, organic, dynamic, good soundstage...a great sounding tube, but only lasted 200 hours. In my opinion much better sound than EH.

Tungsram NOS 6922 (the red writing...military spec). Very neutral, holographic, amazing soundstage, dynamic, lighter tighter bass. Very different to the Gold Lion...a unique sound. I took this out at just less than 500 hours...it was sounding great still but wanted to try the Matsushita. This tube lasted longest in my ET5 so far and don't know how much longer it would have gone...is a spare now!

Matsushita 7dj8/pcc88 with 7v heater filament vs 6.3v on the 6922. Total opposite to the Tungsram it replaced. Organic, beautiful sounding tube. Very even and whilst it is dynamic it has a relaxed organic sound as well. Soundstage excellent. Only lasted 500 hours so was expecting more...but the smallest sample size of 1, as most of my experiences are!!!

The next one I have in now is the 6922 NOS Russian military spec 6h23P EB (premium). It's got a very punchy powerful bass, neutral and even, although I sense a little stridency in the lower treble...but it could be breaking in still and I was used the Matsushita sound I came from last which was very organic sounding. It sounds great though and I'm enjoying the sound...let's see how long it lasts!

Hope this helps anyone looking for tubes for their ET5. Happy listening everyone.