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
 
A nice place to start.  What brand/number tubes came with it?
  One quad of Penta Labs KT88SC, and one quad of JJ 6550. Seller claims they all test around 75 on his Knight KG-600.

...they were able to tell the difference. I wouldn't worry about that!
You are probably correct, but any time I think I know 100% what I am doing is when I find out I learn something new!
  
decooney
1,969 posts
 
@dsper 
A positive comment in a 2009 Absolute Sound test article, fwiw: 
http://www.theabsolutesound.com/articles/tested-conrad-johnson-et2-preamp-lp66s-stereo-power-amplifi...
"When it comes to imaging, the LP66S evinced plenty of tube magic. Image outlines were solidly anchored within the soundstage. When partnering the ET2, it easily kept pace in this respect, giving full scope to a deep and spacious soundstage."
dsper OP
663 posts
 
pkatsuleas  wrote: Unfortunately, can't afford any Tannoys right now! ;-}
They seem to be catching my eye lately as well, though I have never heard them. Seem to have a high cost even used. 
larryi
3,969 posts
 
High cost as used is actually a good sign--the market demand suggests that it well liked.

I have a local dealer that carries CJ equipment.  It sounds good to me.  That dealer also carries the Italian Synthesis brand and that brand is quite impressive for the money.  They build two integrated amps that I particularly like, the A40 and A100.  These come with a very good built-in DAC and utilize KT 66 tubes.  This is not that easy a brand to find, but, it is worth hunting down.
dsper OP
663 posts
 
Okay everyone, 

The Conrad Johnson LP66S was delivered on Sunday and secreted into the man cave.

I set it up today while my better half was at exercise class: Theta ProBasic III DAC, PWT, PL Dialogue Premium, with the LP66S replacing the McCormack DNA-500, and going into Tyler Acoustics MMX5's. Saving the turntable for later.

Initial impressions after about three hours of listening:

First, no problem about power or loudness.

Second, the overall sound seems more dense. I lost some of that when I switched out the Thiel CS5's for the Tylers. Now it is mostly back about 80 - 90 percent. FWIW, I think the Thiels were known for that politeness at the expense of some dynamics.

Third, the bass seems more solid and clear in the mix while still being textured.

Fourth the "spit on the microphone" is back. I am listening to Adele's "19" and it has clearly returned. On the song "Love", there is noticeably more sheen to the celeste. Also more sheen and brass to the cymbals on JJ Cale's "Troubadour".

Fifth, I think there are a few more ambient clues but nothing near holographic that I can hear.

The previous owner was not using the amp routinely and suggested that the amp capacitors might need a couple of long listening sessions to reconstitute the capacitors.....

By the way, I would not be afraid to buy again from "Tuggs" in Washington state. Excellent packing job and the amp looks like new! No trouble with FedEx.

Lastly, given I have changed out both speakers and amps, I have sort of broken the rule about one component at a time. Having said that, there is still a touch of sibilance I noticed after installing the Tylers and may have to change out their resistors. Easy job as they are wired in behind the connection posts on the speaker backs. Or possibly change tubes in the preamp? Or maybe, I just need more time on the speakers as they are now about 75 hours from new :-)! 

Such a fine mess I have created with things to learn and adjust.

So...right now I am happy. 

Thanks for listening and all of the constructive comments. Much appreciated and keep any thoughts coming!

Dsper
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