It looks neat outside, but to me it is always torture to see heatsinks with fins oriented perpendicularly to air flow. Like sandpaper on teeth.
I believe you mean the smaller HS? If so, don't worry they are over specified, meaning that they get just very slightly warm, and are connected to the big top plate for extra heat escape, not at all needed.
As you can see the shunt boards which releases much more heat, have the HS in the correct position.
Well, because I had them laying around to be used, also because I am following the very good implementation from Moglia (thanks also for the help).
The VR tubes don't do any harm, and they look great!!!
Hi Ale,
Well the power supply unit, but already started the job, may be like one to two weeks.
Will keep you posted.
Cheers.
I don't think replacing the 4P1L as a driver is an option - certainly not right now. The LL1660 in 4.5:4 sounds great to me. I don't think this is a problem. My cables can be as short as 15cm (6") so I'm not worried about those.
At the end of the day some Lundahls sound better than others. The LL1660 sounds best to me. The LL1692 or LL1692A has sounded just a fraction more dull to my ears, though quite similar in frequency response. Bass is there. But my LL1692 is gapped for 10mA. My LL1660 is gapped fror 5mA. I could put 7mA through the LL1692 - not sure what that would achieve. I could also try it in 2:1 but I'd be a bit short of gain.
Where I need more gain is in my front end - I'm only getting about 0.5V out of my DAC. If I fixed that up to more like 1 or 2v I'd get better ratios on the transformers.
The LL1692A is a decent transformer. As for the LL1635, it was used in the Amity so it has its fans. It's gapped for 5mA so I don't know what it likes as an input. It saturates at 9mA so should cope with 5mA. Maybe it prefers something more like 3mA. Maybe a 01A.
I don't mean they don't work. I mean my own feelings when I see something similar.
It is sub-conscious reaction, can't do anything about that.
I've never found separating power supplies or monobloks made much impact on a properly designed amp/preamp. On the other hand, if I had to separate anything I'd have one PSU for the line stage with a posh rectifier like an AZ1 mesh, and one for the amp. That can be good and that's what I do. I'm not the only person to have said this is preferable to independent L and R supplies.
Thank you! I always wonder how loud someone pressurizes their listening room in order to affect the tubes with "microphonics" from airborne waves to become a considerable nuisance. Surely, we do not tap the preamp chassis as we listen to music.
I am doing it in my build, but I just cannot comprehend the point of doing it really to be honest. I had experience with 76( in fact one time I had 40 pieces on hand of 76 tubes to choose from) tubes and it is always the tube, not the construction of the chassis that matters if microphonic noise is a concern. You can lift the chassis up, use mass loading, decoupling, etc. and it would not matter. Replace the tube, problem solved!
Thanks again!
Good answer, yes indeed. Experimented in the past with power supplies for the stages with the same phasing (preamp with inbuild phono & line). Compared to the dual mono version it sounded musically closer...
The other hand, building amps (especially power amps) with transformered interstage coupling it becomes physically heavy and seperate chassis brings relief.
BR, Joao
I have a couple of questions:
-About AZ1 hybrid graetz recitfiers, why the first cap is with so small value 0,1-3.3uF when AZ1 datasheets max. value is 60uF? I ask because if I use small 1st cap simulating with psud2 I will need a lot of caps?
-About #26 lineamp is necessary grid stopper & grid leak resistor, I ask because after the OPTs I want to use TVC at the output, I think is not necessary, right?
-About AZ1 hybrid graetz recitfiers, why the first cap is with so small value 0,1-3.3uF when AZ1 datasheets max. value is 60uF? I ask because if I use small 1st cap simulating with psud2 I will need a lot of caps?
-About #26 lineamp is necessary grid stopper & grid leak resistor, I ask because after the OPTs I want to use TVC at the output, I think is not necessary, right?
I haven't found that positioning TVC after OPT have significant effect. I have just tweaking my preamp with AVC, made by Tribute. I have tried at both position, the conventional position as volume control and the position which you mentioned before (I have tried this position inspired based on Thomas Mayer's idea). I found no difference impact (at least in my system). Maybe it's a matter of taste
. One thing for sure the AVC made much improvement in my system. It's like night and day as I replaced my carbon potentiometer with it. About the resistor I dont think that grid stopper is necessary but with your configuration I think you can't avoid grid leak resistor. As it called as "grid leak", it will protect your grid tube when 'sheet' happened (voltage leaking ).