I assume you meant VFM as Value For Money.
I agree and it is a valuable accept in DYI.
So, I need to connect 0-18v and 0-18v in series and I need two transformers.
Correct?
I see and it is not a problem.
I'm afraid that my output will be above 40V with 120V on primary which is designed for 115V.
In due time I will also build a new folded using Salas boards... I did not have time to study it so I do not know if the ft-3 can be installed, but it is surely one of the best interstage caps available.
For the 47n cap I rely on obbligato gold and as for the treble (15n) cap I do prefer relcaps (styroflex on tin foil).
Let us know what you can get.
Off course the values are much more important than cap types, so after you choose your preferred ones, please measure them and post the values here so I can do a proper sim.
PS: I moved to Switzerland so we can not meet in person right now
AS if I can really understand SS electronics
Dear Mr. Salas,
I meant the FOLDED reminded me of the J2 conceptually as IF I understood the concepts!
I guess the only excuse I could make is that both are very simple with nothing superfluous. Both are two stage amplifiers - that much is similar! But I can "see" that the stages are integrated in a way that either disallows or makes two supplies disadvantageous.
I have been caught trying to sound like I know far more than I do!
Thanks to TEA BAG for mentioning the buzz with the SIGNAL transformers. That was my first inclination to use.
ANTEK was my second choice and since there is such a minimal difference in cost for higher VA I was going to go with two of the 100VA. UNLESS there is a reason for not using such a large transformer. Have you found that surplus VA can be deleterious to the sound, benign OR stupid!
While I am going on and on - what is your opinion of using the shielded version? Some like the shielding and some think it brings more problems than it solves. What has been your experience? I am asking in general and not about ANTEK specifically.
AS always, thanks,
Dear Mr. Salas,
I meant the FOLDED reminded me of the J2 conceptually as IF I understood the concepts!
I guess the only excuse I could make is that both are very simple with nothing superfluous. Both are two stage amplifiers - that much is similar! But I can "see" that the stages are integrated in a way that either disallows or makes two supplies disadvantageous.
I have been caught trying to sound like I know far more than I do!
Thanks to TEA BAG for mentioning the buzz with the SIGNAL transformers. That was my first inclination to use.
ANTEK was my second choice and since there is such a minimal difference in cost for higher VA I was going to go with two of the 100VA. UNLESS there is a reason for not using such a large transformer. Have you found that surplus VA can be deleterious to the sound, benign OR stupid!
While I am going on and on - what is your opinion of using the shielded version? Some like the shielding and some think it brings more problems than it solves. What has been your experience? I am asking in general and not about ANTEK specifically.
AS always, thanks,
IMO this build will excel with two tx between 80 and 120VA.
Using TX with larger VA than 120 is not worth the effort (I did not notice any improvements going from 120 to 180VA).
Please note that it will ALWAYS sound very well even with 30VA, but it will sing beautifully with slightly bigger TX (and I do not fancy heating TX).
Surely bigger VA would mean no harm, maybe creating some larger magnetic field on the other hand so the PSU box will have to be a bit more remote.
Botte already tested out a double 36 secondary Antek type with shield terminal that he found it worked well for instance. Bigger but single, so another valid way.
In general, beyond the minimums in the guide, its mainly up to you exchanging new practical tips guys. Or subjective parts evaluations etc. I am sure there will be a range of bit different leanings.
P.S. Botte, how that Antek foil shield works? Is it located between windings, or peripherally to contain some magnetic field? What DC value did it give after rectification on what local mains level?
Botte already tested out a double 36 secondary Antek type with shield terminal that he found it worked well for instance. Bigger but single, so another valid way.
In general, beyond the minimums in the guide, its mainly up to you exchanging new practical tips guys. Or subjective parts evaluations etc. I am sure there will be a range of bit different leanings.
P.S. Botte, how that Antek foil shield works? Is it located between windings, or peripherally to contain some magnetic field? What DC value did it give after rectification on what local mains level?
It seems that the point that I raised about toroids is important to many guys here. I was not expected such large discussion. Thank you all for such valuable info.
Another issue (and it is mostly related to US located guys) is the line voltage. As I mentioned previously, my home line is 118-122v AC 60Hz. ANTEC has 115V mains and this is why I asked question about Hammond 182. It is about twice expensive than ANTECs, but it has 117v primary. Also, transformer quality is the key here.. Right? What can you tell us about Hammond transformers quality (ANTEC vs. Hammond)? Thank you.
I found that you have to double the VA of the transformer to notice much of a difference. Big difference from 30 to 60 and big difference from 60 to 120, next step would be 240 VA and so on.
But I agree 120 VA is plenty big enough.
Rush
Surely getting the proper parts based on what's readily available in different markets is of high interest between builders. Also shipping costs will differ in each area.
I would not say that after a transformer is quiet and steady there is a special sensitivity to this circuit about it. There will be subjective opinions about parts too.
Hammond has a very good reputation. About the Antek 36+36 voltage level I already addressed Botte that he uses it. Such info must come from American continent users to a be precise.
J2 is a differential input with Aleph CCSed output, feedback looped class A JFET & MOSFET amp, if I describe it correctly from the top of my head.
A friend has made it and he likes it very much, even over his F5. But I did not get the chance to compare it. Maybe during this winter.