Standel Transistors

[jessadr]

Any idea on replacements for 69AJ110. SDT5904, SDT9203

[J M Fahey]

Those are probably "inside factory" part numbers, meaning little to people outside, but if you post the schematic we might suggest something based on function.
Standels were pretty conventional amps, not many surprises there.

[Jazz P Bass]

Standel | Schematics

[jessadr]

They are all good numbers just not made in years.

[Jazz P Bass]

Here are the specifications:

SDT9203 Spec Sheets Details Diodes, Transistors, Thyristors, Triacs, Diode Array, Integrated Circuits and Semiconductors — Product Line NPN TO3

SDT5904 Spec Sheets Details Diodes, Transistors, Thyristors, Triacs, Diode Array, Integrated Circuits and Semiconductors — Product Line NPN TO66

The 69AJ110 looks like a PNP TO3 output transistor rated at 80 volts .

[drewl]

The only ones I've worked on had the modules potted inside I had to scrape away to replace a bad preamp transistor.
A standard 3904 worked fine.

[jessadr]

mine is a studio 60 with 6x10's july 17 1970 It doesn't have them. My old custom did.

[Jazz P Bass]

The one schematic shows a 2N4348 as a replacement for the NPN TO3 output transistors.
This distributor shows stock @ 9.00 a pop.

[jessadr]

I am looking at the outputs on a Studio 1970

[Jazz P Bass]

40-45 volt power supply.

Heck, I would throw 2N3055's in there in a heartbeat.

You can even pick them up at Radio Shack.

Is this the amp?
http://standelamps.com/support/schem...uits/ic005.pdf

[R.G.]

Near as I can tell, the power supplies on the amp are +/- 40-45V. A 2N3055 is marginal - very marginal! - at those power supply voltages.

On Semi lists the 2N3055 and the MJ150015 on the same datasheet. 3055's are rated at 60V, the MJ15015 at 120V. Mouser has the MJ15015G in stock (about 500 of them) at $2.85 each.

Even better would be the higher power/tougher MJ15022G. They're $5.87 each, though. The MJ15024 is even tougher, and the same price.

[jessadr]

thank you that is what I was looking for. For the most part use npn or pnp as the circuit and use a higher voltage device. how about the tip42 and tip47 combo with voltages 40/45

[jessadr]

yes jazz p bass that is the circuit.
back in the day I worked for Bluff-City Electronics in Nashville I sold rca 2n3055's by the boxes. I was told if there was a problem they replaced them all. The boxes of 25 had lot numbers. They went in about everything I thought. A lot of country singers sang their tunes though them. But that is Nashville

[J M Fahey]

thank you that is what I was looking for. For the most part use npn or pnp as the circuit and use a higher voltage device. how about the tip42 and tip47 combo with voltages 40/45

No.

You can use TIP31C/32C as drivers, replacing those metallic TO66 ones, or the TO220 ones, if so fitted, but for the outputs you need robust metallic TO3 ones as suggested above.

MJ15015 or stronger.

[jessadr]

Ok I just got some to fix a marshell vs100 . so just wondered so the t03 package is better for higher power ?