Tubes for my ASL AQ2004 pre-amp?

Dan Driscoll · « **on:** 12 May 2004, 04:32 pm »

This should go in the Tube Circle, but it hasn't been created yet.

At least 1 of the ECC82/12AU7 tubes in my AQ2004 is dying, in a fairly noisy manner. When I was doing speaker calibrations earlier this week I had the volume turned up pretty high with no input and heard an intermittant, fuzzy buzz sound from the left speaker. I turned everything off, swapped the left and right tubes, powered back up and after about 30 minutes I heard the same noise coming from the right speaker, while the left was quiet. There is no noise with the pre-amp out of the circuit. I'm pretty sure the reason I hadn't heard it before was because it doesn't get noisy until it has warmed up for half an hour and because I had the volume set unusually high for the speaker cal.

This is the only tube component I have owned and I acquired it very recently. So I'm looking for recommendations for replacements tubes, vendors and an idea of how much I should pay for various versions. I know NOS tubes will generally be more expensive and tubes from some manufacturers are worth more than from others. I just don't know which models and manufactuers or what a fair price is for them. Are there any models or vendors that I should avoid? There's a tube seller very close to me (same zip code) who goes by 'Tubemonger' on Audiogon, has anyone done business with him (or her)?

The AQ2004 takes a pair of 12AU7's and a 12AX7, and I think I should replace all 3. I would like to get 2 complete sets of tubes that are very different, so I can compare them to see what I prefer and so that I have a spare set on hand. It would be great if I could keep the cost under $100, but will go higher if necessary. My tastes run primarily to rock music and my favorite artists are performers like Elton John, Fleetwood Mac, Pink Floyd, The Moody Blues, Supertramp and others whose recordings are not heavily compressed and that do have dynamic range. I also listen to old jazz and some hard rock. My wife likes classical, southern rock and Dido. Any suggestions, info, recommendations or comments are welcome. TIA

ohenry · « **Reply #1 on:** 12 May 2004, 05:06 pm »

Tubes are fun to play with. The choice for you really depends upon your system and it's traits. The originals may turn out to be your favorite.

I run Telefunken tubes in my AQ 2004. They make the high frequencies sound smoother or more refined in my system (it feeds Wave 8's also with telefunkens and Auricaps and single-driver speakers). I have recently added Auricaps to the AQ 2004 and like the results.

Telefunkens are common on ebay and it's easy to become frustrated in bidding for them as they often command too much money. They are worthy additions if you're a patient bidder. You should be able to pick up all three tubes for a little less than $100.

I have read an account where an owner preferred Amperex tubes in the AQ2004. I haven't heard them and they seem to be scarce (=expensive).

Good luck.

vrs · « **Reply #2 on:** 12 May 2004, 05:20 pm »

http://www.boiaudioworks.com/
They do sell matched and burned tubes at a good price.I do like Sovtek LPSAX7 at22$ for a pair plus 5 dollars for shipping.They are not outstanding tubes like Amperex AX7(89$),but good in all aspects.

The newer version of EH and JJ are also reasonable.Give them at least 50 Hours of burn in time.(The much praised mullard AX7 did not work well in my system.)At about 27 dollars including shipping -they do make more difference than cable swapping.The problem with purchasing in E bays is that are they really Matched?We have totake their word for granted.

Dan Driscoll · « **Reply #3 on:** 12 May 2004, 05:26 pm »

Thanks.

For reference, my current system consists of:

Carver SD/A-360 CDC; Panasonic RP-91 DVD-A (for hi-rez stereo); MMF-5 TT; Yamaha RX-V596 (for phono pre and HT only); ASL AQ2004; Sherbourn 5/1500A SS power amp; Vandersteen 2C mains.

The SD/A-360 and Main L/R of the 5.1 outputs of the RP-91 are connected directly to the AQ2004 (CD, AUX). The Main L/R pre-outs from the RX-V596 are also connected to the AQ2004 (TUNER).

gonefishin · « **Reply #4 on:** 12 May 2004, 05:39 pm »

Hi there

What I try to do may suit you too.

What you may want to do (especially if your new to tube rolling) is to buy a pair of NEW decent sounding readily available tubes.

With this...you'll have your noisy tube problem fixed...and your system will be up and running (with minimal money being put out).

As time goes on...do some reading...do some searching as to what tubes (nos or new) you would like to try...then keep your eyes open for the deal that fits your wallet.

When buying NOS tubes, try to stick with a reputable dealer...or if your Ebaying...try to stick with a seller who is known for selling tubes and has good feedback (you don't want to buy NOS or used tubes from an EBAY seller with 900 positive feedback responses who normally sells cookware).

Most reputable dealers and good ebay sellers will try to work with you if you get a "bad" tube. But, during this time...you'll be without your system. Which is why I would get a pair of decent cheap reliable tubes first. Then...as you experiment with rolling...you will always have a back-up set that you know should be good.

For a pair of decent sounding 12au7's...try JJ tubes http://store.electron-valve.com/jjtubes.html
there are better...but these are decent...and fairly reliable. (if you get one of the occasional microphonic ones...just notify the seller for an exchange)

Some that you can keep your eye open for?

I would second the Telefunkens and Amperex both...but I'm sure others can recommend other fantastic AU7's as well.

Have fun!

Carlman · « **Reply #5 on:** 12 May 2004, 05:54 pm »

I've had really good experiences buying from Upscale Audio. If you tell them what you have and what you want to accomplish, they'll make a suggestion you will most likely enjoy. If you also tell them of the issues you're having, and any other little details about what you've noticed about your gear, they'll be even more likely to sell you something you like.

They worked within my budget and provided excellent service.

I've gotten more bad tubes from Ebay than good. I've had bad luck with Chimera labs otherwise I'd recommend him. Not a big deal, nothing personal, just dropped the ball with me the last time and sent a bad tube the time before that.

Good luck,
Carl

vrs · « **Reply #6 on:** 12 May 2004, 06:32 pm »

electron valves are also pretty good.Good price and and they check the tubes before shipping.
For NOS tubes and current production tubes
KENNETH S. CHAIT
ATSI ADVANTAGE TUBE SERVICES
6266 BRANCHWOOD DRIVE
LAKE WORTH, FL. 33467 USA
561-434-3799 FAX 509-696-7736
www.tubeman.com

these people are also good.I purchased amperex and 5751 tubes from them.Yjey are little bit cheaper than upscale audio.

lcrim · « **Reply #7 on:** 12 May 2004, 08:03 pm »

Since you are a newcomer to tube rolling, I would suggest you try reputable, online dealers rather than shopping on Ebay for NOS tubes. This site http://www.vacuumtubes.net/ has very reasonable prices and a limited 30 day guarantee. The site itself can be a source of knowledge. Call them on the phone, they are friendly and very knowlegeable. I am not in any way affiliated w/ them.
Tube rolling can very clearly change the tone of tubed devices. I have already made the mistake of spending a small fortune on NOS tubes on Ebay. I cannot hear hundreds of dollars worth of difference in tonal quality between good cheap ones and good expensive ones.

Dan Driscoll · « **Reply #8 on:** 12 May 2004, 08:50 pm »

Thanks for all the comments and suggestions, they are very helpful. I'll be checking out all those links.

I don't buy on eBay, period. A couple of bad experiences of my own and too many horror stories from others.

I have done pretty well on Audiogon, which is why I was asking if anyone had purchased from Tubemonger. He/she can't be more than 5 miles from my house, according to the zip code. He has a lot of tubes on A'gon and it would be nice to have a source that close by.

Dan Driscoll · « **Reply #9 on:** 19 May 2004, 06:02 pm »

My tubes were delivered this morning, a GE JAN 5751 (12AX7 military variant) and a pair of Electro-Harmonix 12AU7's. The 5751 is technically NOS, but it isn't very old, rare or expensive ($16). The 12AU7's are inexpensive new production tubes that run $10 each. These will get my preamp running again and if I later replace them with some better NOS valves they will provide a very cost effective back-up set.

I bought them from Electron Valve. The prices and shipping charges were very competitive with other vendors and the customer service seems pretty decent. I made a mistake on the order form and they called me within 30 minutes to get the correct info. The tubes arrived in 2 days in a well cushioned package and appear to be exactly as advertised. I'll pop them in tonight, but I figure it will take a week or weeks before I can do any critical listening. Of course, that won't prevent me from doing some non-critical listening.