Vunce has found that even a simple PSU with C’s only and no CRC still works very well - here with 11,000uF per channel and no hum or noise of any kind with ears pressed to speaker cone. This is a special trafo with dual centertap secondaries for dual monoblock worh single trafo at +/-43.5v. Good for about 97w.
So it would seem that the PSU choices are getting to be lower and lower cost.
So it would seem that the PSU choices are getting to be lower and lower cost.
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Indeed X, I’ve been changing psu configuration like you’d swap CD’s. Wait a minute.... does anyone play CD’s anymore 
Just got a set of plain Jane PSU’s fired up. The left unit has 11,000µF, the right unit has 23,500µF of capacitance. The transformer has a pair of center tapped secondaries, so I’ve got essentially a poor mans dual monoblock setup. Sounds nice so far, there is very faint hum if I put my ear right in front of the woofer on the 11,000µF channel. Given this is not a CRC filter, the capacitance is probably on the light side. But, I am surprised how quiet it is overall.
I’m going to keep playing around and eventually I’ll list the combo’s I’ve tried out.
Just got a set of plain Jane PSU’s fired up. The left unit has 11,000µF, the right unit has 23,500µF of capacitance. The transformer has a pair of center tapped secondaries, so I’ve got essentially a poor mans dual monoblock setup. Sounds nice so far, there is very faint hum if I put my ear right in front of the woofer on the 11,000µF channel. Given this is not a CRC filter, the capacitance is probably on the light side. But, I am surprised how quiet it is overall.
I’m going to keep playing around and eventually I’ll list the combo’s I’ve tried out.
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So you guys thought I was kidding about the Griddle Amp?! How little faith you all have in me!
I present to you the $9.92 cast iron Griddle Amp heatsink. It has a grille surface of 16in x 8in (not including the rim and handles or grease well). Weighs about 8lbs and can probably handle 100w of dissipation, no problem. It took a little sanding ith 320 grit and a power sander to get semi smooth. The drill and tap was a breeze - smooth, like buttah.
Picking it up at store:
After sanding and drill and tap operation:
Installing test MOSFETs to check fit:
The ceramic thermal spacers and heat sink compound will be critical to fill in all those voids:
The grease well at the bottom provides a nice flat bulkhead for installing RCA inputs as well as banana plug binding posts for speaker outputs. The width is actually compatible with 17in EIA rack standard. I just need to install a rear frame for the trafo and main PCBs. Or I might mount PCBs to griddle as the holes are almost trivial to tap.
I present to you the $9.92 cast iron Griddle Amp heatsink. It has a grille surface of 16in x 8in (not including the rim and handles or grease well). Weighs about 8lbs and can probably handle 100w of dissipation, no problem. It took a little sanding ith 320 grit and a power sander to get semi smooth. The drill and tap was a breeze - smooth, like buttah.
Picking it up at store:
After sanding and drill and tap operation:
Installing test MOSFETs to check fit:
The ceramic thermal spacers and heat sink compound will be critical to fill in all those voids:
The grease well at the bottom provides a nice flat bulkhead for installing RCA inputs as well as banana plug binding posts for speaker outputs. The width is actually compatible with 17in EIA rack standard. I just need to install a rear frame for the trafo and main PCBs. Or I might mount PCBs to griddle as the holes are almost trivial to tap.
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X and others, two quick questions please:
1. An estimate of when the PCB might be available - for planning and building purposes.
2. What is the “right” +/- PS voltage? I have seen a few different PS voltages mentioned. Could those with an understanding of this amp’s behavior give some guidance on what would be the ideal +/- supply, and some range within which the amp’s performance performance would not suffer audibly. I’m personally less concerned about the power output. The range of acceptable PS voltages would help me and others in a similar situation to decide if a new power tranny is called for or if we could reuse one of those on the shelf.
1. An estimate of when the PCB might be available - for planning and building purposes.
2. What is the “right” +/- PS voltage? I have seen a few different PS voltages mentioned. Could those with an understanding of this amp’s behavior give some guidance on what would be the ideal +/- supply, and some range within which the amp’s performance performance would not suffer audibly. I’m personally less concerned about the power output. The range of acceptable PS voltages would help me and others in a similar situation to decide if a new power tranny is called for or if we could reuse one of those on the shelf.
Hi Francois,
I’ve tried several psu’s with voltages ranging from 40vdc to 53vdc. I’ve noticed more of a difference from the “style” (CRC, CCC or SMPS) of psu than the voltage. I have to gather my thoughts and post my impressions soon.
Your right Francois, one of the nice features about this project is you have a broad voltage range and can use something you probably already have in the parts bin
I’ve tried several psu’s with voltages ranging from 40vdc to 53vdc. I’ve noticed more of a difference from the “style” (CRC, CCC or SMPS) of psu than the voltage. I have to gather my thoughts and post my impressions soon.
Your right Francois, one of the nice features about this project is you have a broad voltage range and can use something you probably already have in the parts bin
The verification boards are on their way to me via DHL Express and should have them in a few days. I need to build and make sure it works. If all good then I will order the production boards. I guess I can open up the pre-orders on my Etsy shop - stand by for that sometime today or tomorrow. Board production time is 3-5days and ship is 3 to 5days. Give me a few days to build it - so about 2 weeks from today they will be shipping out of you have your order in soon.
Great! I will get my order in. I decided to build this “summer amp” before the “winter amp”, as I think of the AN.