Soundstream Rubicon 1002

[Perry Babin]

Check C170, R260 and R264.

While Q174 was out, did you happen to check it (carefully)?

 

[caraudioguy2100]

I will take Q174 back out and check it also will check the other parts listed

 

[caraudioguy2100]

I suspect C170 leaking .

The pads are very corroded .

I will replace the cap and check out a few resistors as suggested

 

[Perry Babin]

Shine a bright light from the back of the board to confirm that there is no dark area between the pads.

If there is a ground plane or trace on the other side of the board, remove Q167 and R260 and confirm that the resistance between the pads is infinite (OL).

 

[caraudioguy2100]

On the pads for Q167

Drain to gate :OL
Drain to source: OL
Gate to source :7.25 M ohm

Replacing the cap didn’t change anything

 

[Perry Babin]

I should have been more clear. Between the pads of the cap.

 

[caraudioguy2100]

Between the pads for the caps the reading is in the mega ohms and when looking at the readings it seems like it’s charging another cap .

 

[Perry Babin]

Did you try to look for a shadow with a bright back-light?

There may be contamination from electrolyte.

 

[caraudioguy2100]

Ok I cleaned the board more and now get OL between the pads for C170

 

[Perry Babin]

Does the amp produce audio with all parts installed?

 

[caraudioguy2100]

Amp will not produce audio with all parts installed .

I don’t have any MPS8099’s on hand to see if they are the fault .

Wondering can I use MPSA06’s in there place ?

 

[Perry Babin]

Post the voltage on Q174 again.

 

[caraudioguy2100]

Replaced Q174,187 with MPSA06 in place
Of the 8099’s.

All parts are installed and amp has output .

Will the 06’s survive in this amp or should I order the 8099’s

 

[Dr Zeus]

Base and collectors are different MPS8099 vs MPSA06. Will need to twist-swap legs 2-3 on MPSA06.

I CANNOT confirm if MPSA06 can electrically replace MPS8099 but they do look similar on paper. If it's working then maybe?

I recommend if you DO buy MPS8099, to ALSO purchase MPS8599 - which is 8099's complement. Soundstream amps use both of these around muting and also auto-current circuits. I have a few of each 8099 and 8599 I could spare, but I dont have a lot. Hard to find I think.

 

[caraudioguy2100]

The 2 data sheets I looked at the pin configuration is the same

 

[Dr Zeus]

You are correct. My mistake.

 

[90scaraudio]

Question on 2sa1304/c3296

Have A question. I have NOS of these A1304/C3296. The C3296-y have a hfe of 216, (all 15 of them). The A1304, they are green with a "T", they have an hfe of 160, six of them, and the rest have lower numbers. Using these in the Rubicon 1002, I was wondering if they will upset the bias as they are not equal?
I can get KSA940/KSC2073 from mouser which have the same specs.

Reason...Its been a few years (10+) and decided to get two of these going. The power supplies are good and I have NOS 2sa1302/c3281 that I'm going to install. The best matched sets. Front end boards are new from Lance, (X-Soundstreem employer) so those are good.

Do I have to worry about the hfe to help make it balanced?

Scott

 

[Perry Babin]

Start a new thread.

 

[90scaraudio]

Start a new thread.

Will Do...