Thanks X,
So it basically answer my question since it looks like powering 2 x Class AB amp module via a single smps is doable and provides great results. I'm also taking into account the added CRC on each channel between the smps and the amp modules. Nice work and piece of wood btw, don't we all have wood for these prototype..lol
p.s. Nice heatsinks, can I please have a link ;-)
Thanks,
Eric
So it basically answer my question since it looks like powering 2 x Class AB amp module via a single smps is doable and provides great results. I'm also taking into account the added CRC on each channel between the smps and the amp modules. Nice work and piece of wood btw, don't we all have wood for these prototype..lol
p.s. Nice heatsinks, can I please have a link ;-)
Thanks,
Eric
Thanks X,
So it basically answer my question since it looks like powering 2 x Class AB amp module via a single smps is doable and provides great results. I'm also taking into account the added CRC on each channel between the smps and the amp modules. Nice work and piece of wood btw, don't we all have wood for these prototype..lol
p.s. Nice heatsinks, can I please have a link ;-)
Thanks,
Eric
You like my $8 amp case? 🙂 2U front blank panel.
Heatsinks by the inch. These are the 7.28in wide model.
7.280" - HeatsinkUSA
Last edited:
Hi X,
My bad explanation. If we used good filtering, we made the smps sound very close to the linear supply; very musical, in fact. But we had to spend as much on inductors and caps to do this as we did for the linear supply; this meant that if we could get the transformer for the same or less price as the smps, it really was almost the same cost in total.
My conclusion: Unless you can buy smps markedly cheaper than the transformer, AND you don't need a lot of filter networks for good sound, then you might as well use the smps, but be aware that most smps units create a lot of RFI, and this affects the regulatory (UL, CE, etc) requirements.
Hugh
My bad explanation. If we used good filtering, we made the smps sound very close to the linear supply; very musical, in fact. But we had to spend as much on inductors and caps to do this as we did for the linear supply; this meant that if we could get the transformer for the same or less price as the smps, it really was almost the same cost in total.
My conclusion: Unless you can buy smps markedly cheaper than the transformer, AND you don't need a lot of filter networks for good sound, then you might as well use the smps, but be aware that most smps units create a lot of RFI, and this affects the regulatory (UL, CE, etc) requirements.
Hugh
Last edited:
Hi X
`I use the Abletec 53v SMPS on my amps like VHEX+ with two pairs of 4700uF separated by rather large two parallel 5R power resistors for a CRC between the SMPS and the amp.`
It is not 5R power resistors way to high values for that CRC filtering ? , I think 0,5R or so is more appropriate value .
Regards !
`I use the Abletec 53v SMPS on my amps like VHEX+ with two pairs of 4700uF separated by rather large two parallel 5R power resistors for a CRC between the SMPS and the amp.`
It is not 5R power resistors way to high values for that CRC filtering ? , I think 0,5R or so is more appropriate value .
Regards !
Hi X
`I use the Abletec 53v SMPS on my amps like VHEX+ with two pairs of 4700uF separated by rather large two parallel 5R power resistors for a CRC between the SMPS and the amp.`
It is not 5R power resistors way to high values for that CRC filtering ? , I think 0,5R or so is more appropriate value .
Regards !
It would be high if you expect high continuous current draw. But depending on your use, a higher R of course gives better filtering and lower ripple, which gives "blacker blacks" for music. I don't play at loud volumes continuously but like high dynamic reserve. This particular R values of 2.5ohm gives me ripple less than 1mV at the amp rail input. This setup will not work for class A as that level of current draw will appreciably sag the rail voltages.
Hi X,
My bad explanation. If we used good filtering, we made the smps sound very close to the linear supply; very musical, in fact. But we had to spend as much on inductors and caps to do this as we did for the linear supply; this meant that if we could get the transformer for the same or less price as the smps, it really was almost the same cost in total.
My conclusion: Unless you can buy smps markedly cheaper than the transformer, AND you don't need a lot of filter networks for good sound, then you might as well use the smps, but be aware that most smps units create a lot of RFI, and this affects the regulatory (UL, CE, etc) requirements.
Hugh
I agree with the cost/performance trade, Hugh. Yes, it only works for this particular Abletec SMPS. It's a nicely designed and made one (Denmark, I believe) and is a close out item that's $20 (free shipping). If it cost $80 - I would have gone linear with an Antek toroidal 300VA trafo and caps. 🙂
Well ,basically I agree that for limited low output power from amp is one OK solution , but for some higher output power it will be significant supply rails voltage pumping effect on the amp side .
Ranchu, I've just produced a set of baords for the citation mosfet 12, configurable as complimentary or quasi complimnetary separate output and driver boards. designed to fit a standard square extrusion. PM me if you're interested ......... you can see pics here on this thread
http://www.diyaudio.com/forums/pass-labs/83434-citation-12-mos-fet-10.html
http://www.diyaudio.com/forums/pass-labs/83434-citation-12-mos-fet-10.html
The latest schematic posted needs to be corrected. Q3, Q4, Q6 & Q7 need to be fixed to the heatsink whereas the schematic shows Q5-Q7 heatsinked.
If someone wanted to use this amp for lets say a kids room with a lower output power, could this amp be powered with a lower voltage supplies while keeping it's magic !!
I have a 200W, +/-25Vdc supply I'd like to use. If this is doable, would I need to change lots of values, if so which one ? Would I have to keep the bias around 125mA like mentionned earlier in this thread ? Sorry about all the questions, this would be a nice, compact and sweet sounding unit.
Thanks,
Eric
I have a 200W, +/-25Vdc supply I'd like to use. If this is doable, would I need to change lots of values, if so which one ? Would I have to keep the bias around 125mA like mentionned earlier in this thread ? Sorry about all the questions, this would be a nice, compact and sweet sounding unit.
Thanks,
Eric
Hi Eric
I can say for certain that this design works with 25V split rails because that's what I'm using! I've lost track of this thread in recent weeks; the circuit I have referenced in post #1 is not current anymore. Give me a little while to trawl through the recent posts and I will point you to the best schematic with component changes for your power supply.
I can say for certain that this design works with 25V split rails because that's what I'm using! I've lost track of this thread in recent weeks; the circuit I have referenced in post #1 is not current anymore. Give me a little while to trawl through the recent posts and I will point you to the best schematic with component changes for your power supply.
I'm interested in 25v rails as well as my current class A test setup is 25v (400VA) with nice CRC filtering via big caps. I just don't want to have to switch out the trafo and PSU's when switching amps.
Hi Eric
I can say for certain that this design works with 25V split rails because that's what I'm using! I've lost track of this thread in recent weeks; the circuit I have referenced in post #1 is not current anymore. Give me a little while to trawl through the recent posts and I will point you to the best schematic with component changes for your power supply.
Thanks for everything Ranchu, no rush.
I believe the latest schematic is on post no.1231 from DACZ. His schematic follows Hugh's last recommendation and is the one with the good connection for C7.
BR,
Eric
step three is done
Not in rush.
I am waiting for last parts- non induction resistors- mouser order to finish
and than finally fire up and test. 🙂 🙄
I think the 25V use was in the early 25 pages that thread- where are shown
Ranchus first own boards 2014.
For better orientation i started to work on a WORD doc- summery of everything significance information. Two first pages to thread page 50 are done.
Will place it later to meanman started thread. 😱
Not in rush.
I am waiting for last parts- non induction resistors- mouser order to finish
and than finally fire up and test. 🙂 🙄
I think the 25V use was in the early 25 pages that thread- where are shown
Ranchus first own boards 2014.
For better orientation i started to work on a WORD doc- summery of everything significance information. Two first pages to thread page 50 are done.
Will place it later to meanman started thread. 😱
Attachments
The point I am trying to make, is that even according to the latest diagram in Post 1231, Q5 is shown as on the heatsink; this needs to be corrected and Q4 should be instead shown as on the heatsink.
Last edited:
- Home
- Amplifiers
- Solid State
- Very simple quasi complimentary MOSFET amplifier