Re: Re: reflections and questions pt 2
He says it's a ST70 Heathkit, but I cannot find anything in the Heathkit museum
http://www.heathkit-museum.com/hvmhifi.shtml
for ST70.
I believe he meant the EICO ST70. I have one and all the trannys are larger than those on my Dynaco ST70s. Also the input is a 12ax7 and driver/spliter is a 6sn7
to the output tubes 7591's.
Babowana said:
ST70 . . . Dynaco . . . ?
Cheers,
He says it's a ST70 Heathkit, but I cannot find anything in the Heathkit museum
http://www.heathkit-museum.com/hvmhifi.shtml
for ST70.
I believe he meant the EICO ST70. I have one and all the trannys are larger than those on my Dynaco ST70s. Also the input is a 12ax7 and driver/spliter is a 6sn7
to the output tubes 7591's.
As I briefed, the improvements come from the combination of the new installation of the regulated power supply and the removal of the limiting.
Improvements are here:
Cutting off the listening-fatiguing aspects . . .
All subjective . . .
Improvements are here:
- In clarity: If you recall the FM TR radio of the battery instead of the wall wart . . .
- In bass end: It goes deeper and wider with definition
- In dynamics
Cutting off the listening-fatiguing aspects . . .
All subjective . . .
Hi All,
I know I'll get shot for this. If sound is too clinical or clean, stay away from metal film resistors. Do not go for low ecr caps for power supply. Contrary to popular belief that low ecr is best, I feel that it's a mix & match thing. Lastly belief it or not an EI transformer will provide a different sound to toroids. To me, EI sounds better.
I know I'll get shot for this. If sound is too clinical or clean, stay away from metal film resistors. Do not go for low ecr caps for power supply. Contrary to popular belief that low ecr is best, I feel that it's a mix & match thing. Lastly belief it or not an EI transformer will provide a different sound to toroids. To me, EI sounds better.
JC951t said:
Quite possibly.
I have built another set of boards with no limiting or thermistors and with carbon film resistors. I have yet to swap out the fairly default boards. I will report on the sound. Still trying to get down different transformer sounds myself.
I think the F5 sounds much warmer on a hot day with the bias sitting about 650mv.
JC951t said:
Alternatively, you can increase the value of the Source resistors to 1 ohms,
and increase the value of the feedback resistors from 2 X 100 ohms and 10
ohms to 1 X 100 ohms and 22 ohms.
The lower amount of feedback will warm the sound up, and you can keep
increasing proportional values in the feedback loop if you wish.
Hi Nelson
I would really love to build this amp, however I would like to build it with a quasi-complimentary (two N channel mosfets) output stage.
Could you show us what the circuit would like with any necessary changes to incorporate quasi complimentary output stage.
Thank you in advance.
I would really love to build this amp, however I would like to build it with a quasi-complimentary (two N channel mosfets) output stage.
Could you show us what the circuit would like with any necessary changes to incorporate quasi complimentary output stage.
Thank you in advance.
I only etched one set of boards when I built it.
I agree with a previous poster, the pinpoint imaging is traded for a much warmer, more diffuse soundstage. I have to move the amp to another room that is more listener friendly to really make a judgement.
Still, this is just my opinion and you know what they say about opinions, everybody has one. YMMV
I'll post again later after I get a chance to listen critically.
Bill
I agree with a previous poster, the pinpoint imaging is traded for a much warmer, more diffuse soundstage. I have to move the amp to another room that is more listener friendly to really make a judgement.
Still, this is just my opinion and you know what they say about opinions, everybody has one. YMMV
I'll post again later after I get a chance to listen critically.
Bill
