2. amps-preamps
  3. 159891-2029

Never Owned a Tube Amp and Want Advice

Hi All, 

I have never owned a tube amplifier before and am planning to purchase one with a minimum of 50 watts per channel to mate with 8 ohm 88 dbl speakers.

My hope is experienced audiogoners will share their expertise regarding how to approach this. While I realize listening is the best way to learn about sound and compatibility; I want to learn a better understanding about brands with less maintenance and longer tube life, how to decide between mono or stereo,can a newbie play with bias or is auto biasing a better first choice, etc.

I would also appreciate what to look for in selecting a used tube amp to identify one that might be in need of repair. For example, with solid state depending on the brand, capacitor replacement can be more of a concern. Any advice on what to look out for or ask about with used tube amps would be appreciated.

A big question I have is how to understand the relationship between power tubes like E34's, 120.s, etc. and, I guess the driver? tubes like 12au7's and 12at7's. That  is to ask which is more critical to the overall sound of the amp? FWIW, I routinely tube roll with my preamps.  

I 've read through a number of threads but maybe someone can point me to good ones I may have missed. 

Thanks for listening,

Dsper
dsper
dsper OP
663 posts
 
Okay, I am being obstinate and have not tried the turntable yet.

I took out the LP66S last evening and reinserted the CODA CS (weighs less than the DNA-500). The sibilance pretty much went away. I reinserted the LP66S today and the sibilance same back.

And I also heard what I would term a harsher sound such that I wanted to reduce volume (Yes, I realize that the volume levels between amps are not the same but there was a harshness).

So....

My tube rolling experience with preamps tells me that you can get these types of effect from different tubes. Does the same thing hold true for tube amp 6922 driver tubes?  

Currently, there are Electro Harmonix tubes in the two driver positions and a Sovtek Reflector in the input/phase splitter position.  I know I do not like Electro Harmonix in my CJ preamp.

Wonder would happen if I changed out the Electro Harmonix tubes? Many blog comments indicate that many users do not like them....

Any thoughts?

Connected with Ty Lashbrook and he suggested changing the tweeter  resistors to a four or five ohm from the installed 3 ohm; I am thinking the tube change should come first. 

Thanks for listening,

Dsper



atmasphere's avatar
atmasphere
11,785 posts
 
My tube rolling experience with preamps tells me that you can get these types of effect from different tubes. Does the same thing hold true for tube amp 6922 driver tubes?  

Currently, there are Electro Harmonix tubes in the two driver positions and a Sovtek Reflector in the input/phase splitter position. I know I do not like Electro Harmonix in my CJ preamp.

Wonder would happen if I changed out the Electro Harmonix tubes?

You've just put your finger on exactly the problem with using 6922/6DJ8s in amplifiers. Its hard to find a good one! The tube is very prone to microphonics and harsh sound. The Russian tubes IMO made this problem even worse.


Yes, if you have decent tubes the sound of the amp will change quite a lot. I've personally had terrible luck with the EH 6922. IMO, its pretty easy to find better sounding tubes than any of the Russian-made miniature tubes- 12AX7, 12AU7, 6922 and so on. Its not surprising at all to hear that a microphonic 6922 is causing silibance!!
dsper OP
663 posts
 
I have a pair of 1960's Amperex NOS "Butt Uglies" coming from Brent Jesse. Figured to try them even though they are like double the price of the Sovtecs and EHs.

If they improve things, then maybe I might try some" really good", i.e., expensive ones.
dsper OP
663 posts
 
I remembered that I still had the EH's I took out of my CJ preamp when I put in Phillips....

Anyway I substituted those for the EH's in the tube amp and it helped.

Can hardly wait for the butt uglies to arrive!

Dsper
jetter
3,033 posts
 
Butt uglies, any flavor, rule!
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