[fernan]

En esta PSU Mod Adamus, ¿debería funcionar con EZ81 y disipadores más grandes para TIP50?

¿O mantener el + HT original para los filamentos? Para 6,3V 4A tengo CT, desaparecen las resistencias 100R, 64K y 10uF ... ¿Alguna sugerencia?


y / o doble fuente de alimentación, estoy preparando el amplificador balanceado?

Me alegra ver este hilo abierto después de la desaparición de la web anterior Cavalli

Muchas gracias

 

[Zulkr9]

Anybody know how to contact glassjar audio, seems to be unresponsive

 

[bhjazz]

Anybody know how to contact glassjar audio, seems to be unresponsive

That is, unfortunately, common. I have not checked in with him in a number of years but his site still appears active. Give him another try or two.

 

[Zulkr9]

also would ike to know is it worth it buidling the bijou, or is the crack better

 

[Martinrm]

Who's still enjoying their Bijou? Was getting ready to sell mine since I had switched to SS for the past few months. Plugged it in and forgot why I loved my Bijou so much. Now it's my daily driver again.

 

[bhjazz]

I dragged out my Bijou project, determined to finish it. Embarrassing.

For the first test, I connected only the power input to the transformer and the Bijou power supply board. I'm using the 370DAX transformer. I had the requisite 100K/2W resistor sitting at the 250VDC output of the power supply. I'm also using a poor man's variac to limit current inrush for these first tests.

Upon adding power, the output started slowly ramping up to around 25VDC. At this point I saw a small trail of smoke rising from somewhere between the back corner of the power supply (near C5, one of the large caps) and the transformer. I powered it down immediately.

So far, though, everything checks out. As there are no versions of the power supply board template around anymore (not even on the wayback machine) I found the schematic and recreated it myself. And from this I found that everything is in the right place on my board.

Tomorrow I will test the transformer by itself, just to ensure the output is within expected values. I believe unloaded it should show higher values.

Otherwise, I'm a bit stumped. The ps board is clean as a whistle as far as flux. All I can think is that either this is ...normal... for the first startup ever, or that the MOSFETs are blown. Even in that case, only R5 would be overheating and mine seems to have taken no damage. No smoke is what I truly expected.

The transformer is mounted sideways, not mounted upright on it's tabs. The unused input and output wires were bundled and heat-shrinked together. I probed that area with my nose to see if I could find anything that seemed burnt. (nerd!)

Again, stumped. Ericj or funch...if you're still out there...

 

[bhjazz]

Unloaded tests of the transformer:
I removed the Bijou PS board to isolate what the transformer is doing. These values seem really off. Here are the test results for the secondaries. These are in reference to ground.

Secondary Wire Color	Specs (VAC)	My Tested Values (VAC)
RED-YEL	0	124.7
RED	260	58
GRN	6.3	169
GRN	6.3	171
RED	260	306

Primaries are connected like this:

 

[ericj]

Unloaded tests of the transformer:
I removed the Bijou PS board to isolate what the transformer is doing. These values seem really off. Here are the test results for the secondaries. These are in reference to ground.

Secondary Wire Color	Specs (VAC)	My Tested Values (VAC)
RED-YEL	0	124.7
RED	260	58
GRN	6.3	169
GRN	6.3	171
RED	260	306

Primaries are connected like this:

Red-yellow should be literally ground. It's the center tap between the two red secondary wires. So, double-check how the transformer is connected to the power supply board. Maybe post pics.

And make sure there's nothing shorting some pins on the bottom of the board.

 

[bhjazz]

Big thanks.

I'm only testing the leads directly off of the transformer. The ps board is not connected.

First, the connection from the mains to the transformer. To be clear, hot is connected to the transformer black and blue, neutral is connected to white and brown, as per my post above. (EDIT: the twisted red wire goes to ground.)

Here are the leads coming out of the bottom of the transformer. Primaries at the top, secondaries on the bottom.

 

[bhjazz]

Power Supply board bottom side.

Power supply board top.

 

[bhjazz]

Red-yellow should be literally ground. It's the center tap between the two red secondary wires.

So I'm testing this in VAC mode with one probe at ground. Perhaps my test is being done incorrectly?

 

[bhjazz]

The 370DAX voltages:

 

[bhjazz]

Email dispatched to Hammond. I had a chat with a fellow DIYer who works on old computer displays, and he feels the transformer has failed. More soon.

 

[ericj]

(EDIT: the twisted red wire goes to ground.)

What in the heck do you mean by "twisted red wire goes to ground" - where do those wires come from?

You sure none of the wires coming out of the transformer are damaged?

 

[ericj]

With no power connected, can you measure resistance between the two red primaries?