What projects can I build around a pair of 400VA Toroidy Supremes which only have a single 25vac secondary?
if the secondaries are used in series then you can power chip amplifiers and discrete power amps .
if money is not an issue then go for modulus 286/686.
if money is not an issue then go for modulus 286/686.
Completely open to suggestions of what can be built around this. Asuslover makes a good suggestion, any others?
If you don´t mind Class-A and chassis cost I´d think big MOFO amp monoblocks could be very nice if you have an appropriate preamp.
Juma has a 25W SE class-A design that sure is nice and is designed for ~40VDC.
Using 2 transformers for dual rails you could go with paralleled chipamps as suggested (if speakers are 8Ohms) or one of the numerous class-AB designs around here.
You would need either a very big chassis or put the power supply in a separate chassis.
I´d say you would need some kind of speaker protection and probably also inrush current handling sensing both voltage rails; a combined design like from the diyaudio store is probably sensible but there are others around.
(with Class-A you could use NTC like a CL60)
I would make it depend on what you need/want and your speakers need.
Either way you will have a very nice and beefy power supply.
Juma has a 25W SE class-A design that sure is nice and is designed for ~40VDC.
Using 2 transformers for dual rails you could go with paralleled chipamps as suggested (if speakers are 8Ohms) or one of the numerous class-AB designs around here.
You would need either a very big chassis or put the power supply in a separate chassis.
I´d say you would need some kind of speaker protection and probably also inrush current handling sensing both voltage rails; a combined design like from the diyaudio store is probably sensible but there are others around.
(with Class-A you could use NTC like a CL60)
I would make it depend on what you need/want and your speakers need.
Either way you will have a very nice and beefy power supply.
If I have 2x good quality 400VA but only with one 25Vac secondary each, this is what I would do :
Each Tx for a monoblock.
Use half wave rectification to get +/-35V raw DC (with ripples) :
https://www.eleccircuit.com/dual-dc-power-using-2-terminal-transformer/
Then use a regulator after the first caps to reduce the ripples significantly.
Still good for +/-30V+ after diode and regulator dropout.
The transformer can then deliver a bit more than 5A when fully loaded.
For Class A amp, the maximum bias current needs to be at least 2.5x lower, i.e. 2A.
That means with sufficienly large caps after the regulators, peak output current can be up to 4A.
A Class A design like the Zenquito would fit nicely.
https://jm.plantefeve.pagesperso-orange.fr/sche.html
For Class AB amps like Nelson's AB100, you will not have enough voltage to make full use of the Tx fully.
https://www.diyaudio.com/community/threads/ab100-class-ab-power-amplifier.227503/
Unless of course you go balanced / bridged, or you have very low impedance speakers.
Patrick
Each Tx for a monoblock.
Use half wave rectification to get +/-35V raw DC (with ripples) :
https://www.eleccircuit.com/dual-dc-power-using-2-terminal-transformer/
Then use a regulator after the first caps to reduce the ripples significantly.
Still good for +/-30V+ after diode and regulator dropout.
The transformer can then deliver a bit more than 5A when fully loaded.
For Class A amp, the maximum bias current needs to be at least 2.5x lower, i.e. 2A.
That means with sufficienly large caps after the regulators, peak output current can be up to 4A.
A Class A design like the Zenquito would fit nicely.
https://jm.plantefeve.pagesperso-orange.fr/sche.html
For Class AB amps like Nelson's AB100, you will not have enough voltage to make full use of the Tx fully.
https://www.diyaudio.com/community/threads/ab100-class-ab-power-amplifier.227503/
Unless of course you go balanced / bridged, or you have very low impedance speakers.
Patrick
Parallel for each channel, essentially two mono amps in the same housing.
Or build a single 200VA per channel stereo unit, keep one aside for later.
That should be enough for most uses.
Or build a single 200VA per channel stereo unit, keep one aside for later.
That should be enough for most uses.
Mofo is a good idea, but only works well with sensitive speakers as far as I understand.
LuFo looks like a better bet: https://www.diyaudio.com/community/threads/lufo-amp-39w-se-class-a-from-28v-rail.372679/
TPA3255 could be a good one to - https://www.jlelectronicsph.com/product/sylph-d100-tpa3251-stereo-amplifier-module-ready-to-run
Do all all TPA3255 implementations and SE class A amps work with single rail power?
LuFo looks like a better bet: https://www.diyaudio.com/community/threads/lufo-amp-39w-se-class-a-from-28v-rail.372679/
TPA3255 could be a good one to - https://www.jlelectronicsph.com/product/sylph-d100-tpa3251-stereo-amplifier-module-ready-to-run
Do all all TPA3255 implementations and SE class A amps work with single rail power?
Oooo… I like the look of this.
https://www.diyaudio.com/community/...h-abbb-52w-class-a-amp-gb.339086/post-6449123
https://www.diyaudio.com/community/...h-abbb-52w-class-a-amp-gb.339086/post-6449123
This one’s not appropriate… the search continues…
I guess products that use external laptop power bricks are a good place to consider as well?
Could be nice for a replacement for the 36v DC mean well SMPS for the Sony VFET?
https://diyaudiostore.com/pages/vfet-information-page
https://diyaudiostore.com/pages/vfet-information-page
Got it - Salas L Adaptor is ideal for this and I can power a number of supporting electronics with it.
https://www.diyaudio.com/community/threads/l-adapter.336685/#post5761291
https://www.diyaudio.com/community/threads/l-adapter.336685/#post5761291
