rdaneel
100+ Head-Fier
- Joined
- Apr 1, 2008
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I will, prepro. I'm interested in hearing for myself what starving the cans for power will do (apart from lower the volume!).
I will, prepro. I'm interested in hearing for myself what starving the cans for power will do (apart from lower the volume!).
I wonder how long this will last?
Probably until the next meet........
Pretty sweet wuwhere! You have a vintage amp rated at 50W @ 8 ohms do you not? What model amp are you using?
From my favorite tube dealer's site....."Like a warm British jacket of the finest tweed, these glorious tubes have an attractive sweet warmth in their midrange and lower regions. The top end is silky and pleasant, without being rolled-off. The best of these tubes retain a fine sense of "air" at the top, and the upper midrange is smooth and liquid. These tubes reproduce the human voice, especially female voices, with haunting realism."
I'm using a vintage Copland CTA 504, designed by Ole Møller, a Danish who used to work for Ortofon as an engineer before leaving to form the Copland company making tube amps and tube preamps. He was inspired by the sound of the Conrad Johnson tube amps.
I did some research on this amp since it uses valves which can be rolled with NOS varieties and still put out 50 watts. I read the sound that the amp produces described as, "the presentation is somewhat romantic, warm and liquid," which is right up my alley since that is the sound presentation that I prefer. I even found one for sale in Singapore.
The problem for me however, is that it is not self-biasing. I think an owner of this amp needs to have some expertise in this regard, which you obviously possess.
I'm sure you have a lot of fun listening to the 6 with it. Perhaps you know that I am running the 6 from the taps of a BAT VK-55SE which is a splendid amp in its own right but does not have the flexibility that the Copland does with tube choices.
Happy Listening
Yes it is not self-biasing and I had to figure it out because there was no user manual and all the previous owner sent me was a picture of the trimpot with a drawing of where the setting should be because he didn't know either (you can still find his plea for assistance in agon). Anyway, I used the manual for the CTA 505 which says set it at 45mv across the test resistor. When I set it at 45mv the sound was thin so I knew it was wrong. Then I measured the test resistor on the 504, it was 10 ohms, the 505 was 1 ohm. That was it, I had to set it 450mv instead of 45mv.
@ Dr Roberts and wuwhere
this is a bit off topic, but are there sonic benefits to having non self biasing amp. Makes you wonder why all designers dont make them that way. much obliged for your insights.
It's a geek thing. Having the voltages within .01 % of each other makes ya feel warm and fuzzy. I used a GTA SE40 and had to bias it after rolling new tubes.Sorry Cante Ista, I have never listened to a non self-biasing design but I'm sure wuwhere would agree the auto-biasing feature is a heckuva lot more convenient.
It's a geek thing. Having the voltages within .01 % of each other makes ya feel warm and fuzzy. I used a GTA SE40 and had to bias it after rolling new tubes.