Post your Solid State pics here

"Infidel" input stage , "blameless" like the "Wolverine" ..... Output stage is modular EF3 for 100-120W/8R.
A floppy cable can connect IPS - OPS. LED/cascoded VAS soft clips (unlike other similar designs). 5PPM/20Khz @ 100W/8R.
Runs ice cold at full power with 0 mV offset. Any input stage can be used .... Leach /CFA - or any classic design.
OS

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That was one of my "builders" creations above. I want to see/hear what 300V/uS slew sounds like (CFA +Hawkford cascode).... I want servo action , too !
And REAL soft tube like clipping . All hail the "Hellraiser" ! I know that output stage works well - all that counts.

OS
 

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G'day Guys,

I finally got my P3A finished.
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ESP P3A boards and P33A speaker protection boards.

I found a 300VA 24v-0v-24v power transformer cheap second hand and modified the secondaries for 2x 24V so that I could run dual bridge rectifiers as is my preference.

The power supply uses 4x Nippon Chemicon SMH 15000uF 63v caps I got cheap amongst a whole bunch of other caps from what I suspect was an estate sale.
Home brew PSU board
Also home brew speaker jack mounted relay boards for the speaker protection.

The power switch and power supply wiring were salvaged from a Wega Polaris 3 Group coffee machine. Coffee machines are a gold mine of electrical wiring and switches. The wiring is all high temp, 600v rated and very flexible stuff. The switches are usually rated for at least 15A often 20A+.
I love the heavy duty clunk with these push type switches. They usually server as a manual over ride for the group heads on a volumetric type coffee machine.
Me being me, I have to cover everything in PTFE braid.

The chassis is based on a Pioneer VSX-3300 I got for $1.
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I liked the grill on the lid and it was just the right size. However the base plate and back panel were filled with all sorts of annoying stuff: holes, stamped features etc.
I remade the base and back out of some sheet steel I salvaged from an old dishwasher.
I also added a steel front for shielding and so I could attach the front panel.
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I also added some dimples to the sides so they could be fastened to the base plate using a makeshift dimple die (bolts, nuts, washers, a socket and an impact wrench). Without the plastic front the lid is designed to fit into, everything would just flop around. I never quite got the lid to sit perfectly flush.
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The heatsinks were originally one 430mm long job I salvaged from some faulty receiver or another.
I cut it in half and folded up some brackets out of more dishwasher steel.
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Vent holes for the heatsink consisted of some 124 holes with a step drill bit. Step drill bits are freaking amazing. Mine is just a cheapy from our local big box hardware store but it keeps going and going. Well over 1000 holes so far it it still cuts through sheet like butter.
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All the fasteners are hex head stainless steel because philips should not exist. Except of course, the 4 bolts holding on the front panel which are black oxide hex head....

You may notice I love rivet nuts. I use the stainless ones from Ali Express. The quality of these can vary. Some are too thick and break my tools, some are thin and feel too easy.

All the steel was stripped and painted with a couple of coats of Rustoleum Flat Black.

The front panel is some salvaged Mahogany I got a decent chunk of for $20. This will feature on a few more amps before it runs out.
Lots of Danish Oil and a few coats of high gloss clear coat.

Back panel labels were made by my wife out of adhesive white vinyl.

How does it sound?
Warm and detailed like a P3A should.
G'day mate! I want to like your post but i dont know how! Good job!
 
I had for sale 2 blowtorch gain stage modules and someone asked if I could build the entire preamp for him.
The reason for selling them was because they were heating too much in my 2u enclosure. I needed to replace the heatsinks that were installed initially with taller ones and use a 3u enclosure in the new build.
 

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It's a work in progress, as all my projects are. It's a stereo car audio amplifier based around the Irs2092. It works great but I'm still figuring out the case situation. Tl494 controller at 65khz. 55v rails, STF25N10F7's for the audio and the venerable irf3205's on switching duty. The board is 70x90mm and is good for about 150 watts into 4 ohms. Has over volt, current, and thermal cut out. Oh, and it's bridgeable
VERY impressive and compact solution. My amps are bigger and do not include the PSU. Well done!
 
JBL-Urei 6260. I think they have some sort of Leach/Otala inspiration . Circa 1985-1989.

Wide open loop over audio frequency range, lowish amount of negative feedback. Opamp unity gain input, VAS stage runs very hot on these. Caps were a bit too close to regulators so I mounted them under the board. An Opamp senses DC and fires transistor relay. Current limiter transistors for low impedance current protection. Sanken outputs. Big old transformer. Current output doubles at half impedance.

A bit hissy, distortion measures reasonably well.
 

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