Sjöström Audio DIY forum

In my experience, crafting a custom phono preamp can significantly enhance your vinyl listening experience. However, what if the best designs are not just about the components we choose but also about the unique sound signature we aim to achieve? Could it be that the most satisfying phono preamps are those that reflect our individual tastes rather than strictly adhering to technical specifications?

I believe that the choice of components in a phono preamp can significantly shape the listening experience. If we assume that every component contributes to the overall sound signature, what happens if we deliberately choose mismatched parts to create a unique audio profile? Could this lead to unexpected sonic pleasures, or would it simply result in chaos?

Are you satisfied with your current audio quality, or is there room for a significant upgrade? Which components or modifications have made the biggest difference in your DIY projects?

2 mV typ and max 5 mV is expected on the TPA6120a and max 100 uV times the gain. 7.3 mV is a bit much according to datasheets. How much do you have on AD8610 output?

Notice that THS6012 is the industry version with more detailed specs. Input bias currents may have some influence. Anyway 7 mV is not much.

Both transistors are dead.

The 27 V zener should also be dead. Check if you have max 27 V across it if you have supply voltage applied. Make sure you have a current limitation otherwise you will fry it. You can also do a diode test. RED wire on anode (ground) and BLACK on cathode. You should get 0.6-0.7 V.

Espirit wrote

Quoteheaveno
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Hi
Board 1
T1
B-E= 143mv
E-C= 40mv
C-B= 0.0-0.6mv

T2
B-E= .4v
E-C= 22.6v
C-B= 0.0-0.6mv

Board 2
T1
B-E=.623mv
E-C= 22.2v
C-B= 1.8mv-6.6mv

T2
B-E= .4v
E-C= 22.2v
C-B= 0.0mv-2mv

Both coils changed

Regards
James

Today got the TPA8610 and put it in. Now everything seems to be ok.

I measure 4,7 mV on left output and 7,3 on right. Between left/right out 2,6 mV.
What else should I check.

Also the Alps Pot 2712 10K is OK?

Thank you
Branko

It's really hard to tell why this happened. The first guess is soldering.

Desoldered TPA8610 and Pin 1, 2, and 4 are shortened right side seems ok. Will now order one for replacement.

What could have dstroyed it? could not find a reason on the board?

thx

Found a short (50 Ohm) between +12V and -12V in the left side! No short in all the small 805 parts around the regulators and the AD8610. Pins 1 to 4 of the TPA8610 set also short (about 25 Ohm).

Right side is different here. Maybe the TPA8610 is the problem? (was presolderd)

Should I try to desolder the TPA8610?