Tube newbie needs help with 6922 recommendation

Doublej · « **on:** 24 Mar 2006, 01:10 am »

I need some guidance on replacing the 6922 tube in my Assemblage L1 Signature preamplifier (Sonic Frontiers SFL1 Signature successor)

It has the stock 6922 in it. I have no information about the manufacturer. The manual says the unit can handle a 6922/E88C/6DJ8/ECC88 tube type. (I assume without making any mods to the circuit board?)

I am looking for a replacement that will provide greater detail and increased imaging. Right now I feel the sound is kind of bland and 2 dimiensional when mated with a Plinius SA-50, with less detail and PRAT when compared to a Teac Reference 100 receiver or a Technics SA SU7700 integrated amplifier. Given that the Assemblage/Plinius combo is something like 10x the price of either of the other two, I hope there is a way to better the sound of this combo.

What should I consider, how much should I expect to pay and what are some good sources for the purchase of a replacement tube? Will I be able to get significant improvements by changing the tube or should I just sell the Assemblage and start over?

I could replace the tube with a 12AT7 but this requires removing the circuit board to move a jumper some I am loathe to attempt this unless I can expect a huge improvement in the sound quality. There's no easy access to the underside of the circuit board.

MarkR7 · « **Reply #1 on:** 24 Mar 2006, 01:37 am »

It would help to know what tubes you have in there now.

When I ran a 6922-based preamp (a First Sound Presence Deluxe mkII), my favorite tubes were US made, white label Amperex 6922s, white label Amperex USN-CEP 7308s, and Philips SQ E188CC, in no certain order.

Good luck with your quest!

audionutter · « **Reply #2 on:** 24 Mar 2006, 01:47 am »

I used to have equipment using the 6922 tubes. My personal favourite was the Mullard CV 2493 which is a 6922/E88CC tube. Very good indeed and rated as amongst the best 6922's available. No longer in production, as the last of them British made/England made Mullards were back in the 70's. However, still available on Ebay and in fact I sold my last pair on Ebay to a guy in England last month.

elcaptain88 · « **Reply #3 on:** 24 Mar 2006, 01:55 am »

Before you spend a small fortune on NOS tubes - try the current production JJ E88 tubes, they are very good.

skrivis · « **Reply #4 on:** 24 Mar 2006, 02:42 am »

Quote from: Doublej

I need some guidance on replacing the 6922 tube in my Assemblage L1 Signature preamplifier (Sonic Frontiers SFL1 Signature successor)

It has the stock 6922 in it. I have no information about the manufacturer. The manual says the unit can handle a 6922/E88C/6DJ8/ECC88 tube type. (I assume without making any mods to the circuit board?)

It would help if you knew the actual specs of the original tubes, and what the circuit requires. Then you can make a rational selection for a replacement tube - assuming you know the specs of the replacement.

Unless you find someone who has an Assemblage L1 Signature preamp, any suggestions you might get here are worth exactly what they cost you.

steve k · « **Reply #5 on:** 24 Mar 2006, 02:50 am »

I've also found the best detail with the Amperex PQ Gold Pin 6922 made in USA. Of the new tubes I've tried, I like the Ei Gold Elite 6dJ8. It is very well balanced--not as forward or detailed as the Amperex but still very full across the spectrum. The Electroharmonix 6922 is a nice tube also with really tight, full bass but in my preamp, the highs are a little grainy.

skrivis · « **Reply #6 on:** 24 Mar 2006, 03:03 am »

Quote from: steve k

I've also found the best detail with the Amperex PQ Gold Pin 6922 made in USA. Of the new tubes I've tried, I like the Ei Gold Elite 6dJ8. It is very well balanced--not as forward or detailed as the Amperex but still very full across the spectrum. The Electroharmonix 6922 is a nice tube also with really tight, full bass but in my preamp, the highs are a little grainy.

Oh, so you have an Assemblage preamp just like the OP's?

No? Bzzzt! Thanks for playing.

Tubes don't have a "sound" of their own. They have certain characteristics that may translate into a "sound" in a particular circuit.

Your opinion that a given tube in your preamp sounds just spiffy is not worth anything to someone else who has a different preamp.

Unless you actually have specs on the tube and know how it relates to the original tube in the OP's preamp? No?

I've found that the Electroharmonix tube in my preamp sounds absolutely horrible. It's the worst tube I've ever heard in my preamp. Yuck! They should be shot for making such crap!

Oh, yeah, I forgot to mention that my preamp requires 12AX7s. Details, details....

gld · « **Reply #7 on:** 24 Mar 2006, 03:04 am »

I agree, try the JJ's they are very good. I also like the Amperex 7308's.
I ship all of my new preamps with the JJ's, very quiet , musical, and they don't cost alot!

Gary

warnerwh · « **Reply #8 on:** 24 Mar 2006, 03:45 am »

Try the Ei Elites. Smooth and rich in the mids and highs, you give up a tad on bass tautness though.

steve k · « **Reply #9 on:** 24 Mar 2006, 04:02 am »

Quote

Your opinion that a given tube in your preamp sounds just spiffy is not worth anything to someone else who has a different preamp

I disagree. If a given tube sounded different in every preamp, there would be no consensus whatsover on what is a good sounding tube or bad, bright, or muddy, tipped up or bassy. Why even post your opinion?

I agree with you on the EH 6922's. I don't like them in my preamp because they are grainy on the top. I don't see why another preamp would make them sound different.

I would bet that if you took a poll of tube users, you'd find very definitively that certain brands of tubes have certain inherent sonic characteristics. Some preamps may emphasize certain aspects of a tube's inherent sound more than others but I doubt an Amperex is going to sound like a Mullard in another preamp.

skrivis · « **Reply #10 on:** 24 Mar 2006, 04:06 am »

Quote from: steve k

I disagree. If a given tube sounded different in every preamp, there would be no consensus whatsover on what is a good sounding tube or bad, bright, or muddy, tipped up or bassy.

I haven't noticed much of a consensus.

Quote

Why even post your opinion?

Exactly.

hehe

Quote

I would bet that if you took a poll of tube users, you'd find very definitively that certain brands of tubes have certain inherent ...

It very much depends upon the circuit in which they're used.

steve k · « **Reply #11 on:** 24 Mar 2006, 04:21 am »

So have you heard EH's in an Assemblage?

Doublej · « **Reply #12 on:** 24 Mar 2006, 08:32 pm »

All I have to work with is the following:

The existing tube says Sovtek 6922 Made in Russia 98
There is only ONE tube in the entire preamplifier
I have a schematic and an asembly manual.
I have basic specifications, i.e input/output impedance and gain.
I think I have a digital photo of the top side of the circuit board.

What now?

skrivis · « **Reply #13 on:** 24 Mar 2006, 08:56 pm »

Quote from: steve k

So have you heard EH's in an Assemblage?

No, but I wasn't the one making recommendations for "good-sounding tubes," now was I?

skrivis · « **Reply #14 on:** 24 Mar 2006, 08:59 pm »

Quote from: Doublej

All I have to work with is the following:

The existing tube says Sovtek 6922 Made in Russia 98
There is only ONE tube in the entire preamplifier
I have a schematic and an asembly manual.
I have basic specifications, i.e input/output impedance and gain.
I think I have a digital photo of the top side of the circuit board.

What now?

I guess you could try for some NOS Sovtek tubes, on the assumption the designer picked it for a reason. The Tube Store has them.

http://www.thetubestore.com/sovtek6922.html

miklorsmith · « **Reply #15 on:** 24 Mar 2006, 09:08 pm »

Considering the poster is looking for a sonic change and currently has Sovtek, buying a replacement Sovtek and hoping for improvement is poor advice.

If you only need one tube, those small ones are usually pretty cheap. Buy a few and have some fun.

steve k · « **Reply #16 on:** 24 Mar 2006, 09:19 pm »

Quote

No, but I wasn't the one making recommendations for "good-sounding tubes," now was I?

No but I'm not sure how trashing EH tubes did the poster any good either. At least I suggested some tubes that I thought met his criteria. I presumed that was what he was looking for. But obviously you know better.

Several other posters have suggested their favorite 6922's as well (some of which agree with my suggestions) based on their experience with other preamps and somehow they escaped your trash talk. I'm sorry that my suggestions don't meet your personal criteria for a worthwhile post is. Obviously the other posts somehow met your qualifications though.

The next time I'm looking for a fight, I'll post here. I suggest you get back on your meds.

MarkR7 · « **Reply #17 on:** 24 Mar 2006, 09:23 pm »

I never heard anyone say anything good about any Sovteks in any preamp. Absolutely do not replace them with more of the same garbage.

There are a lot of good choices brought forth in the above posts. They are all compatible in your preamp. Find them, buy them, and try them to see what works best in your preamp for your listening preferences. That's what we all do.

skrivis · « **Reply #18 on:** 24 Mar 2006, 09:43 pm »

Quote from: miklorsmith

Considering the poster is looking for a sonic change and currently has Sovtek, buying a replacement Sovtek and hoping for improvement is poor advice.

If you only need one tube, those small ones are usually pretty cheap. Buy a few and have some fun.

I didn't say it would be an improvement, but it would be to spec. Hey, maybe he'd get lucky and the original tube is just worn out and replacing it would fix things.

Simply recommending some "good-sounding" brand of tube is blowing smoke up his rear. It's stuff like this that produces huge prices for NOS stuff on Ebay.

You can't recommend tubes for this person unless you have the same preamp they do.

If you know the circuit, know the specs of the stock tube, and know the specs of the replacement tube, you can make some general observations. That's it.

Oh, and how do you know the "good-sounding" tube you buy is the same as the one Joe Blow recommended? You don't, because Joe never measured the real parameters. You don't, because the place selling you the tube doesn't have a "good-sounding" dial on their tester - assuming they do test it.

Hey, maybe you'll get lucky and love the new tube. What are the chances? How much will you spend trying to get to somewhere when you don't even know where you're going?

skrivis · « **Reply #19 on:** 24 Mar 2006, 09:44 pm »

Quote from: MarkR7

I never heard anyone say anything good about any Sovteks in any preamp. Absolutely do not replace them with more of the same garbage.

There are a lot of good choices brought forth in the above posts. They are all compatible in your preamp. Find them, buy them, and try them to see what works best in your preamp for your listening preferences. That's what we all do.

What's wrong with Sovteks?

Are you saying the original designer didn't know what they were doing when they used Sovteks? Hmmm.... maybe he just needs a new preamp?