golden tube SE-60

[davidgotubes]

I have a goldentube SE-60 and from what I understand they are pretty rare and I cant find any info on this baby so pretty much anything would help (espesly bias) thanks I also have just acquired a pair of paoli MKIII's they are so fine but the same story with these i cant find any info.

david

[Parrot]

Welcome to the Forum. I believe Golden Tube Audio is out of business.

The SE stands for single-ended, and the 60 means it puts out close to

60W per channel. Manufactured in the late 1990s.

[codhead]

Contact Jeff Glowacki at Sonic Craft (soniccraft.com). He's THE authority on Golden Tube mods.

I had 5 SE-40's at one time, and yes, they are a NIGHTMARE to bias.

Your SE-60 is essentially an SE-40 with an upgraded power supply to

support EL34 tubes. If I remember correctly, the circuit board says

SE-40/SE-60 on it (same part in both amps).

Sonic Craft has some reliability mods (replaces under-spec'd diodes,

upgrades the PS caps, and upgrades the cheap bias pots with 10-turn

military grade parts). Their mods came in stages, and were also

available as a kit, if you're proficient at soldering.

Anyway, I'd give Jeff a try. He can probably answer any questions you have.

[codhead]

I'd try to verify the SE-60 bias voltage, but the procedure should be

the same. If you're missing the bias adapter, it's the exact same plug

as a computer's hard drive power connector (which you can use to

construct one). The ground is at one end of the connector, and the next

3 wires correspond to the bias pots for the 3 tubes of the respective

channel.

BIASING THE GOLDEN TUBE SE-40 AMPLIFIER

1) Set the amplifier on the work surface facing you

2) Remove the 2 screws from the left side

3) Stand the amp up on the left side (where you just removed screws)

4) Remove the 2 screws from the right side (now facing up)

5) Remove the 6 screws from the bottom cover

6) Remove the bottom cover

***WARNING*** VOLTAGES ARE PRESENT INSIDE THE AMPLIFIER CHASSIS THAT

CAN CAUSE DEATH ON CONTACT. IF YOU HAVE ANY DOUBTS REGARDING YOUR

ABILITY TO SERVICE ELECTRONIC EQUIPMENT, TAKE IT TO SOMEONE WHO DOES

THIS FOR A LIVING. ALWAYS MAKE ADJUSTMENTS WITH A PLASTIC SCREWDRIVER

OR ALIGNMENT TOOL DESIGNED FOR THIS PURPOSE.

7) Connect the power cord

8) Connect the bias adapter to the lower connector

9) Set your multimeter to DC volts

10) Connect the black meter lead to the red wire

11) Connect the red meter lead to the yellow wire

12) Turn on the amplifier

13) Wait 3 minutes

14) Adjust the rear pot for 630 mV (0.630) left increases, right decreases

15) Move the red meter lead to the black wire (next to the yellow wire)

16) Adjust the center pot for 630 mV

17) Move the red meter lead to the black wire (next to the red wire)

18) Adjust the front pot for 630 mV

19) Turn off the amplifier and allow it to cool

20) Connect the bias adapter to the upper connector

21) Repeat steps 10-19

It may be necessary to repeat this procedure several times before the bias

readings are all in spec. Do not exceed 640 mV. Do not set bias over 630 mV,

as input power fluctuations will cause the bias voltage to slightly increase.

[davidgotubes]

thanks so much for the reply and I dont mean to dowbt you but are you sure about the 630mV I just want to do it right thanks again

[codhead]

The 630mV is the spec for the SE-40. I'd suggest measuring what your

amp is set to now, and using this as a baseline. If 3 or more tubes

measure very closely, use that value to set the remaining tubes. This

will most likely turn out to be something less than the recommended

setting, as the bias voltage tends to drop as the tubes age.

There's a Golden Tube user's group over at Yahoo, and someone there

might know the recommended bias voltage. You could also try posting a

free want ad on Audiogon for a copy of the SE-60 manual. I did this

with my first SE-40, and someone sent me a copy within a few days.