Sound Skulptor forums

Build help and troubleshooting => TS500 Tape Simulator => Topic started by: hasanova on December 08, 2022, 08:25:11 PM

Title: No Output - solved!
Post by: hasanova on December 08, 2022, 08:25:11 PM

Hi,

I've built two TS500's. One is working with correct output voltages. The other has no output.
- Correct power voltages (+16/-16 VDC).
- Peak-meter is working and I can set it correctly.
- I've swapped all IC's, on both units, but still no output.
- I've Re-touched solder joints, still no output.
- I've compared continuity on the transformers of both units, but both were still in circuit.

Where should I look?

Title: Re: No Output
Post by: JPK on December 10, 2022, 11:31:55 AM

Check there is no DC voltage on TP7.
Check if you can follow the signal with your AC voltmeter on TP3, TP4, TP5, TP6 and TP7.

Title: Re: No Output
Post by: hasanova on December 10, 2022, 08:54:49 PM

Conditions	OUTPUT = 26.6 mVAC	TP7 = 0.376 VDC
input signal = sine 1kHz 0.4 VAC	OUTPUT = 0.00 VDC	TP3 = 2.439 VAC
(on input XLR between pins 2&3)		TP4 = 2.439 VAC
30” dpi		TP5 = 2.433 VAC
TAPE SAT on left (min)		TP6 = 2.231 VAC
BIAS/EQ on right (flat)		TP7 = 4.178 VAC
Both pots on 10
TS500 ON

Title: Re: No Output
Post by: JPK on December 11, 2022, 11:05:51 AM

Check the output transformer coils resistors:
- between TP7 and 0V : 5.2 ohms
- between output hot and cold : 23 ohms

Title: Re: No Output
Post by: hasanova on December 22, 2022, 07:17:25 PM

I had trouble logging in on the forum for a while, but in the end we sorted it out: it was a defect in the output transformer.
I already swapped it for a new one, all is well in Audio-Land ;)

Thank you JPK!