If I recall correctly, it seemed to be more of a supply issue than anything else. I have the 24 volt relays in my build. I don't see any inherent advantage one over the other, I just remember something about different current draw between the two choices. I do remember putting a small heat sink on the regulator that feeds them, but it was only because I try to run devices at a cooler temp when possible.
Just so I can get a grip on this, I am curious as to the total number of hours that was spent building this. I have only done a project of this level once or twice in my life. I am not referring just to the actual build itself, but the planning and the seemingly immense amount of time making something look pretty and not just functional. It is in the details. Something as small as your choice of the bracket used to support the rod. It looks to be substantial instead of the very common flimsy brackets that are usually offered. And the top. To be predrilled perfectly. It is one of those things that any difference in spacing or smoothness is often picked up by the eye. Congratulations are in order here.
irrelevant, practically
always good to have more choices
doable even with 6Vdc relays, but then you must engage brain regarding dissipation of mosfet and VA of xformer
invest some pleasant time, brew or coffee or beer or wine, and investigate pictures of already made builds
let it settle
repeat if needed
and you'll have a plan emerging
and even then you'll invest less time than I needed to invest in construction, or Patrick to work on initial or ongoing organization of kits
Thanks, couldn't think of a reason unless somebody has a stock of one or the other.
availability reasons, nothing else
or you'll rather prefer that I wrote just one single type, obsolete, expensive, exclusively made by Japanese Virgins during Fool Moon ...........
or you'll rather prefer that I wrote just one single type, obsolete, expensive, exclusively made by Japanese Virgins during Fool Moon ...........
Zen,
Good advice in order to love what you do. I really study some of these builds, and there are things that become excellent ideas for a build, while others direct me in a way of 'I wouldn't do it that way'. So much of what I build is by hand, so I must be very careful as I go, and not be tempted to speed ahead. If you have the funds, there is no shame in letting a professional help with, let's say engraving for example. But then you have to trust that the engraver 'gets it'. Some are close to shameful at any price.
Good advice in order to love what you do. I really study some of these builds, and there are things that become excellent ideas for a build, while others direct me in a way of 'I wouldn't do it that way'. So much of what I build is by hand, so I must be very careful as I go, and not be tempted to speed ahead. If you have the funds, there is no shame in letting a professional help with, let's say engraving for example. But then you have to trust that the engraver 'gets it'. Some are close to shameful at any price.
Just about to order transformer, but didn't think there would be much benefit in two, one 60VA for both boards, I can't see crosstalk being a problem with the power supply on the Iron board ? Or have I missed something ? Plan is to use a single transformer with a Saligny rectifier and a pair of 10,000 uF caps on a small side board, then feed to both Iron boards bypassing the position where the rectifier diodes would be.
Steve,
My take on this would be that if a single transformer were used for both channels, then a shield between secondaries would benefit (one secondary for each channel. No sharing)
My take on this would be that if a single transformer were used for both channels, then a shield between secondaries would benefit (one secondary for each channel. No sharing)
why not 1.6KVA???
just 4K++ posts in this thread, pretty much clear that 2pcs of 10VA each, are more than good
From Toroidy the audio supreme potted transformers (shield between pri/sec and goss band plus potted in external stainless case) are supplied in the same outer case for a number of different power ratings, so the 50 or 60, which I looked at is the same size as the 30. So I thought I'd buy a larger one which gives option to use it for something else if I find I want to replace it with two. 60 is a useful size, small amplifier, headphone amps, pre-amplifiers, DAC... If I buy one 30VA transformer my options are more limited.
But the question really was, is one transformer going to do the job as well as two transformers ? Given the Iron boards have a pretty good regulator on them I thought one transformer would be good - less noise. I've seen some very nice pre-amps with one and also with two transformers.
I've got some interesting ideas for cushioning the cables to reduce microphony if you want to hear those ? 😀
But the question really was, is one transformer going to do the job as well as two transformers ? Given the Iron boards have a pretty good regulator on them I thought one transformer would be good - less noise. I've seen some very nice pre-amps with one and also with two transformers.
I've got some interesting ideas for cushioning the cables to reduce microphony if you want to hear those ? 😀
simple as this - if going Bal, use benefits of proper dual mono approach, you have with separate channel pcbs
for my own Iron Pumpkin ( and other pre builds), I'm cheating ....... easy when having custom donuts - one donut is having two sets of secondaries, one set dedicated for each channel
remember , with signal Iron present, you need to take care of stray magnetic fields; local PSU Donut is just first of them
so, thread carefully - 10VA per channel is enough; if going to more, there is always increased possibility of hum; going bigger is not bringing any functional benefit ......... so really all waht's left as puzzle is thinking about availability but then, again, no use to go class above what's already overkill (say 60VA vs. 30VA)
regulators in Iron Pre (even if shunt) aren't brute force approach, demanding zillion of heat watts to deliver.
btw. my Donuts are exquisite quality, small, with static shield and with magnetic shield, and placed furthest possible from signal Iron
for my own Iron Pumpkin ( and other pre builds), I'm cheating ....... easy when having custom donuts - one donut is having two sets of secondaries, one set dedicated for each channel
remember , with signal Iron present, you need to take care of stray magnetic fields; local PSU Donut is just first of them
so, thread carefully - 10VA per channel is enough; if going to more, there is always increased possibility of hum; going bigger is not bringing any functional benefit ......... so really all waht's left as puzzle is thinking about availability but then, again, no use to go class above what's already overkill (say 60VA vs. 30VA)
regulators in Iron Pre (even if shunt) aren't brute force approach, demanding zillion of heat watts to deliver.
btw. my Donuts are exquisite quality, small, with static shield and with magnetic shield, and placed furthest possible from signal Iron
Well put, and I will add that since this smaller value transformer size will cover all of your needs, including the internal shielding and all, make it a given for this project. Many times when I have overbuilt a power supply gigantic or even less transformers, I got the headache of additional issues from it.
In the case of microphonics with cables, I am not into that, but, here again is a case for a smaller transformer that is more than adequate to do the job, with less mechanical buzz. So that is a consideration that makes good common sense.
Lastly, I go with my own chassis builds mainly because I can get a very well-made chassis at a lower price, with a solid chassis floor. Just my prejudice but punching 100 holes in the bottom of a chassis never appealed to me, although handy for the many ideas about placement of everything inside.
In the case of microphonics with cables, I am not into that, but, here again is a case for a smaller transformer that is more than adequate to do the job, with less mechanical buzz. So that is a consideration that makes good common sense.
Lastly, I go with my own chassis builds mainly because I can get a very well-made chassis at a lower price, with a solid chassis floor. Just my prejudice but punching 100 holes in the bottom of a chassis never appealed to me, although handy for the many ideas about placement of everything inside.
Thanks, point taken 👍🙂 I'll order from my usual UK supplier Tiger, as his are well balanced and very quiet and without the stainless outer, will be very small.
C13-C20 220uF - is 16V acceptable or do I need 25V ? I have a number of nice 16V parts, that's all, happy to buy new if necessary.
C1 and C2 need to cover DC voltage after bridge, while all other caps need to be just above rails voltage (15Vdc)
exception - cap in relay circuit, I believe C11 in all options - it must be above relay voltage
exception - cap in relay circuit, I believe C11 in all options - it must be above relay voltage