tube amp mentor needed!

[Jakob]

I am very interested in trying a tube amp for my 2441's and 2405's. But I can't tell one tube from another and there are so many designs, alot of them old.
Is there anyone out there who has tried several tube amps (maybe with my drivers) and can give me some help where I should start looking. I don't mind building something myself, and I can't afford McIntosh's. I tend to listen at high levels sometimes, so I guess I need some power, 60 watts or so at least.

All help appreciated!


Thanks!!!

[hapy._.face]

60 watts of tube power is quite high. Perhaps half that amount. (??) The wiring for most tube amps is pretty much the same (as far as set ups go) with only slight variances from manuf to manuf. Don't pay for aesthetics, unless that's a big concern- than by all means- go for the rubbed walnut face on the triple chrome chassis!! Really, it's all about the TUBES in use. For example KT88's are the rockinist tubes I know of, IMO. A good matched pair can set you back for more than most pay for the entire amp. However, KT88's are usually unreliable. EL84's and EL34's are really sweet and much more reliable- still a bit pricey though. My point here is- why tubes at all? Don't get me wrong- I own a pair of Cary monos and I like em- but I wouldn't buy em again (or any other tube amp) based on what I know now.

This whole debate (tubes vs solid state) has been exhausted so many times in length, but I see your posting as an ideal way to get my 2 cents in. Sorry in advance...

I'll TRY to keep my sweeping, generalized opinion on the subject short and sweet (too late, huh?).

You mentioned price being a big concern. I can already tell you- you will have no luck with tubes if you mantain a strict budget. I wouldn't pay the ransom for McIntosh amps either. Tube amps decay constantly. Technically - they never sound the same twice. They need constant biasing and replacing. This=money (eventually). Plus, most entry level tube amps can still sound quite nice- but I personally don't want to hear my amp at all !!!! I want to hear the MUSIC!! Most tube amps implement some sort of sonic signature (albeit pleasing to me) it is still an interferance with the recording/peformance. If reference quality amplification is what you seek (with tubes)- you need to ante up to the really good ones. So, price is outta the picture here. In contrast- you can get an excellent solid state amp that performs as reliably as a good dog with no BS for a LOT less!!

BUT- if you just gotta have your tube sound- and you want to fly cheap- There's a (seemingly) nice pair of old RCA monos on ebay right now which can just cut in under the McIntosh amps ($$$ wise): http://cgi.ebay.com/PAIR-OF-MONOBLOCK-RCA-TUBE-AMPLIFIERS-PRO-QUALITY_W0QQitemZ5856090750QQcategoryZ39783QQssPag eNameZWDVWQQrdZ1QQcmdZViewItem
(I bet they perform better, too).

Why not pick up a good tube preamp- but use your good solid states for the muscle??

You can also try a good homebrew amp (integrated or not). Most of these follow tried and true point to point wiring diagrams and use excellent parts. Be prepared to start off with fresh tubes, btw.

I don't trust any of the millions of amps coming outta China/Hong Kong, though...

Here are two others that look good to me (they may suck in actuality):

http://cgi.ebay.com/Opera-EL34-Remote-Integrated-Tube-Amp-the-tuner-guy_W0QQitemZ5855189771QQcategoryZ3280QQrdZ1QQcmdZ ViewItem

http://cgi.ebay.com/Fisher-30A-Tube-Power-Amplifiers-Geat-For-JBL-Speakers_W0QQitemZ5855551825QQcategoryZ71547QQrdZ1 QQcmdZViewItem

Good luck!
Mike

[spkrman57]

I am very interested in trying a tube amp for my 2441's and 2405's. But I can't tell one tube from another and there are so many designs, alot of them old.
Is there anyone out there who has tried several tube amps (maybe with my drivers) and can give me some help where I should start looking. I don't mind building something myself, and I can't afford McIntosh's. I tend to listen at high levels sometimes, so I guess I need some power, 60 watts or so at least.

All help appreciated!


Thanks!!!

For the efficiency you are running I can see no reason why 7 to 9 watts would not drive you out of the room. So for running compression drivers which are in the neighborhood of approx 110db/watt or higher that should fill the bill.

For the midbass and bass and subwoofer duty the solid state amps are best used for duty.

Ron

[Steve Gonzales]

Hey Ron,

I've been using an EL34 based, VTL Model 45, 45wpc to drive 3 pairs of JBL 1" drivers at the same time. 1 pr of 2421's,2420's and LE85's in my triamped system. I can achieve VERY loud output with very life-like, very musical results. I A-B'ed this amp against a high quality, pure class A SS amp and decided to go with whichever amp was most pleasing to my ear. There is definately something special about this combo that defies mere specification data. Try a newer amp first until you get the hang of this tube "thing", as alot of the older amps can be troublesome and quite dangerous to your speakers, should a 30-40-50 year old cap,resistor or other component qive out and fry something , that is unless you've acquired the amp from a reputable dealer that can asssure you that the amp has been rebuilt with new parts or serviced and specs out correctly. It still amazes my that a mere 45wpc can deliver the "goods" and do it very well. Good luck in your search and get ready to experience something special, Steve G

[norealtalent]

I mostly agree with speakerman. Horns are super efficient meaning a few watts go a loooooong way. I would still run tubes on my midbasses just for the sound but then to each their own. I am partial to the el84 and el34 tubes. You get great sound and reliability and they are very plentiful and inexpensive, for tubes. I've had a number of various tube amps and use a CJ 100wpc, el34 amp to run my 10" midbasses, 2" horns and 2405 tweters. I love the el34's. Now on to the Cary comment, I have a little 30wpc Cary stereo amp that uses 2 el34's per side. I know what the el34 tubes can do and love them but don't like the Cary. It has no music quality, no depth, transparency or dimension compared to any other el34 amp I've used. I've tried mant different tubes and it still doesn't compare to the el34 based VTL that I gave Steve Gonzales for his first tube amp. Hence, it's not the tubes, it's the Cary that sucks. I'm not saying all Cary's suck, just like JBL's, some are better than others relative to what you're looking for and accustomed to. I also have a pair of Golden tube SE40's with 5881 sovteks in them. The sovteks are factory and I don't really care for them either. I've tried sovtek el34's and don't care for them either so I conclude that sovteks are not good audiophile tubes but I know some guitar players that love them.
Tubing is an experience, it's the real journey that has no destination. I love my CJ and that is what I have finally gone back to after a year of playing other amps. Out of all my games, I have learned I want el84's or el34's for sound, reliability and availability with out mortgaging my house. I had a couple of pair of 300b amps but I could retube ALL my amps for what one pair of those cost. I liked the sound but it wasn't enough power for my midbass and the tubes were more than I wanted to spend. I sold them. And they were new age China built, but they sounded sweet! Thats only half my $.02 but more than enough for starters. :bouncy:
EDIT: Speaking of the devil, he jumped in there while I was typing. I was hoping you'd chime in here!

[scott fitlin]

Yup. Jakob, see what these guys are telling you about power and compression drivers? They are all very right, you wont need many watts at all to make the 2441,s deliver!

FWIW, and this is just as a matter of power equation, I run SIX 2441,s on JBL 2395,s 3 per channel on a Crown D-150A. 80wpc@8ohms, I guess I have a nominal 30 watts or so per driver. My system is a commercial system, and midrange is not something I dont have enough of! Your 2441,s will sing on a few watts of good tube power!

[jandregg]

1) Tube amps run at lethal voltage. They can and have killed.

2) Tube amps must be adjusted periodically, every six to 12 months.

3) Tubes wear out and must be replaced. Some are quite costly.

4) Tube amps have killed and will kill again. Learn how to properly discharge an amplifier before doing anything else. Always keep one hand in your pocket when working on a tube amp. Keep tube amps away from children and pets.

[scott fitlin]

1) Tube amps run at lethal voltage. They can and have killed.

2) Tube amps must be adjusted periodically, every six to 12 months.

3) Tubes wear out and must be replaced. Some are quite costly.

4) Tube amps have killed and will kill again. Learn how to properly discharge an amplifier before doing anything else. Always keep one hand in your pocket when working on a tube amp. Keep tube amps away from children and pets.So tubes are a sound to die for? So to speak!

:D

[Audiobeer]

When you check the listings on Audiogon those killer amps (Tube amps) are always sold in the first day or so. :D

[louped garouv]

I used to have soem M19s that I ran with a heathkit aa-151 tube amp (14WPC, EL84/6BQ5)

solid performer with blues, jazz, classical; but the tubes couldn't keep up with the bass when trying to listen to modern EDM

I run my 075s with tubes ocassionally....

[John W]

Here is a schematic for a push-pull kt88 amplifier. I've built one similar to this with different power and output transformers and really like it a lot. This amp is nice for a novice builder due to the low parts count, and super performance. The key is the llundahl interstage transformer used to drive the output stage. These transformers are a little pricey here in the US, but since they are made in Sweden you may get a better deal.
An amp like this will give you a lot more punch than a single ended.
http://www.audiodesignguide.com/my/pp3.html

[louped garouv]

heres a sound practices artice that talks of triodes... with several schematics...

[Flodstroem]

Hi Jakob

Why not give this amp. concept a try A Zero Feedback Impedance Amplifier design by Susan Parker.

This is a Power MOSFET amp including a bias transformer, and an output transformer. Very similar to a valve amp but MUCH easier to build. You could even build the driver/bias and output transformers by your self.

I havnt given this approach a try but I would like to get in contact with somebody who would like to try this amp out. This amp has some very good qualities. :)

http://www.diyaudio.com/forums/showthread.php?s=&threadid=42259&highlight=

Maybe somebody in the forum have given it a try????
Regards

[Flodstroem]

some additional amp. highlights

by the designer Susan Parker:

Zero feedback.
Balanced and isolated input and outputs.
Output configurable to drive any impedance load, from electrostatics to sub-ohm parallel linear array loudspeakers
Good EMI/RFI performance.
Low voltage operation ( sub 60 volts ), no potentially lethal HT.
Only two power semiconductors required for Push Pull version.
Minimum components, little opportunity for noise generation (150 dB signal to noise ratio).
No capacitors in the audio signal path.
"Direct" signal connection from input to output.
:bouncy:
Regards

[Steve Schell]

What a great thread! As some of you know I have been nuts about tube equipment for years now. There is something so inherently natural and lifelike to the sound of tubes that to me even the best solid state gear misses the mark somehow, adding a sterility and a distancing from the music by comparison.

There are reasons for the superiority of tube sound, and for the tremendous tube renaissance of the past two decades. Tubes, especially triodes, are the most inherently linear amplifying devices known to man. When run in simple circuits, with little or no negative feedback, the sonic results can be really satisfying. Distortion products may look higher than SS when measured in a ham fisted way like THD, but the proof of the pudding is in the listening, as it were. Common measurements have a poor correlation with listening satisfaction in my opinion.

Trying to figure out what type of amp and preamp to use, and how much power... it is a huge subject. At first glance not much power should be needed for average listening levels on a fairly efficient speaker like most JBLs. I am used to very high sensitivity horns systems, which produce around 108dB at one meter with a one watt input. It may sound crazy, but I do most of my listening with a single ended homebrewed 45 amp, which puts out 1.6 watts on a good day. It doesn't run out of gas until the peaks get above 110dB or so, and tubes clip so gently that the result is usually just a mild compression of peaks. The peak to average ratio of a good, uncompressed recording is so high though, that to really reproduce the transient peaks properly requires a fair amount of power, even with the high sensitivity. With a typical JBL speaker with sensitivity in the mid 90s, 30 to 50 watts is certainly not too much power.

Which brings up the next dilemma, trying to find a higher power tube amp that is as communicative and involving in the listening as a good low power single ended directly heated triode amp. Push pull amps, which often have plenty of power, rarely offer the suspension of disbelief in the listening of a SE triode amp. One solution is an amp with an output device like an 845 or GM-70 that will deliver 30 watts or more in single ended duty. These amps tend to be heavy and ridiculously expensive in terms of amps per watt, at first glance anyway, because they run on 1200+ plate volts. There are several companies making such amps nowdays; deHavilland makes good stuff, and is as good a place as any to begin getting a feel for what is available.

http://www.dehavillandhifi.com/index.html

Jacob, the best way to sort out what you need is to take every opportunity to listen to as much equipment as possible. Entry level into tubes used to be Dynaco, Eico, Scott, Harman Kardon etc. but these days there are a ton of inexpensive imported amps available. Some of these are built badly and unreliable, but not all. The cheapest way to great and reliable sound is home building, but of course there is a learning curve to climb. Reading the threads on the Audio Asylum tube forums is a great way to familiarize yourself with what is out there and what people are doing. Believe me, it is worth the time and effort to learn about tube gear!

[rloggie]

Steve,

I've also had many tube amps in the past ten years. Push-pull, OTL, Kt88, EL34, then 300b SE, 2A3 PP (14wpc) and now a 211 driven by 300b that I have yet to run. So far I liked the 2A3 sound better than the rest. Using it to drive S8R, I kept the passive volume to no more than 1/4 (loud). I would highly recommend trying the 2A3 if you can find the one that puts out the appropriate wpc for your needs. Most recently many seem to be going to the 45 tube. Could you describe the sound vs. 2A3 (with horns)?
Thanks,

[Nightbrace]

I agree a tube pre-amp, will give you great results coupled with a great solid state amplifier. On a budget I'd highly recommend late 60's Dynaco tube preamplifiers.