50w Single-Ended BAF2015 Schade Enabled

[dantwomey]

Looks correct to me. The speaker outputs from the CCS PCB and Gain PCB will obviously need to be tied together off board before going to +SPKR.

The +28V output from the CCS board will connect to "D" or pin 3 on this boards MOSFET. I caught a little hint from ZM's build. Instead of putting a solderable mounting hole on the PCB. I connect directly with a crimp on ring connector directly on the MOSFET.

Regards,
Dan

 

[Zen Mod]

oh yes, that ZM is one clever chap

 

[dantwomey]

Gave myself a brain ache here trying to keep up to ZM and Father Pass. That aside, here's a pic of what my final input board may look like with optional buffer.

Regards,
Dan

 

[MEGA_amp]

Looks great!

 

[dantwomey]

Off to OshPark soon!

 

[flaklapp]

KOA Speer BPR58

Check Mouser,

Koa Speer BPR58 5W.

Best,
Frank

 

[dantwomey]

Took ZM's advice again and created a small LM317/LM337 PS to feed my optional buffers.

Regards,
Dan

 

[dantwomey]

Having trouble with email attachments so here are some of my KiCAD files.

 

[MEGA_amp]

Big thanks to Dan...My KiCad/PCB fabbing addiction is in full force. I went the 317/337 route as well, but put a 'mini' PS before it.

 

[cubicincher]

to MEGA_amp #1289

Looks really good!


I also made a seperate small PSU for the bias and for the input-buffer. My buffer
is outside of the 50W-SE-Schade-amp. This amp is hot!


Greets
Dirk

 

[dantwomey]

Big thanks to Dan...My KiCad/PCB fabbing addiction is in full force. I went the 317/337 route as well, but put a 'mini' PS before it.

When I first inquired about using KiCAD I was warned about the steep learning curve. I found the YouTube tutorials (especially John's Basement) were a huge help and made getting use to KiCAD easy.

Regards,
Dan

 

[toto34]

Good evening, gentlemen.
Where can I buy the input transformers (JT-123-FLPCH).
By thanking you in advance.

 

[MEGA_amp]

You can try direct from jensen, email probably works best:
High performance audio transformers and ground isolators.

I purchased mine from the link below, great service from these guys:
Jensen Transformers JT-123-FLPCH Line Output Transformer, PCB Mount

 

[toto34]

Thanks again Mega amp for your link ,order this morning

 

[dantwomey]

Getting back to my Schade after many distractions.

My CCS seems to be working and producing tons of heat. But I'm perplexed by my second mosfet passing 3.3 amp and being stone cold?

Regards,
Dan

 

[Zen Mod]

Rail, output node voltage?

physics can't be cheated

 

[dantwomey]

You'll have to give me some hints. I've been off doing other things so now I'm a bit rusty!

Regards,
Dan

 

[Ben Mah]

Rail = power supply, relative to ground

Output node = speaker out node at the resistor string between the two mosfets, relative to ground. It should be in the neighbourhood of 30v.

If you are measuring 3.3A through the first mosfet, it must be going somewhere.

 

[dantwomey]

Rail voltage is 59.6 vdc. Where it's supposed to be 30v it's 1.7V.

For fun I connected a 4 ohm 500W resistor to the CCS 28 volt output alone to ground and it drew the same current (3.3A) and the current was adjustable via the pot.

The heatsink I have the mosfets mounted on is standalone and not connected to the ground of the power supply. Could that be it?

And no current flows at all until I apply about 6-7v bias to the second mosfet.

 

[Zen Mod]

Mu part is having Iq set, whatever voltage across is

you need to set bias of lower pqart of amp, to set equal voltages ( 50% of Rail voltage) across each half of amp

read Singing Bush Tips 'n' Tricks thread