Eros 2 Build [resolved]

[Paul Birkeland]

Do you have one channel that's now sounding correct?

[David E]

Paul, That was good thinking, but No both channel failed. I've started doing a complete rebuild
on paper with a check list. I'm on page 52 now.

[David E]

Well I went over everything again and I only found that in a couple of places I used the Lower instead of Upper solder point. would that make a difference. Check out my notes on page 47, item 5, last on the page. My reading on resister was high 48, 60 ohms. Where do I go from here. DLE

[Paul Birkeland]

I would reflow the rest of the non-LED solder joints on that center front C4S board.

[David E]

OK, PB but this is a stupid question, is it best to remove the C4S board and reflow from the back or careful reflow from the front?

[Paul Birkeland]

Definitely reflow from the back.

[David E]

Still sounds like shI*, here are the voltages as of reflowing the C4S board:
1A - 218.5 VDC
1B - 219.1
OA - 155.8
OB - 160.2
OC - 98.0
OD - 98.0
OKA - 98.7
OKB - 98.7
OKC - 1.53
OKD - 1.50
PB, I'm flustered but thanks for sticking with me through this, DLE

[Larpy]

Given your voltages, I wonder if the issue is the bias of the 6922 tube.  I had a problem with my Eros2 sounding bad for no reason I could account for, and Paul Joppa eventually diagnosed the problem as the bias of the 6922 tube.  The Eros needs at least a 1.5v difference between OC/D and OKA/B.  Less than that and you get distorted sound.

I was unable to fix mine.  It's in the cue to go to PB for repair.

[Larpy]

Scroll down a few posts to see PJ's take on my unhappy Eros.
https://forum.bottlehead.com/index.php?topic=15304.30

[Paul Birkeland]

When I take these on for repair, typically it's a matter of reflowing solder joints, and an occasional mistake.  It's tough to offer a whole lot more than that.  Occasionally I see a dead 6922 that will cause similar issues to what you have, but swapping that tube hasn't yielded much in the way of results.

[David E]

PB, in your opinion is the problem most likely in the C4S board? I played my turntable directly in to my S.E.X last night and it was great, is the problem in the output of my table? Does my turntable already have a pre-amp in it, its a Audio-Technica AT-LP120XUSB?

[Paul Joppa]

Yes, that TT has a phono preamp built in. There is a "phono/line" switch on the back. Set it to "Phono" to bypass the built-in preamp and use the Eros instead. (Set it to "Line" to direct connect the TT to the S.E.X. amp. See the downloadable manual on page 8.)

[David E]

Well Damn, I been chasing stupid. All's well in the South, Thanks a million and the Eros sounds amassing.

[Paul Joppa]

LOL  :^)

On the plus side, you did eventually identify the real problem!

[Mucker]

Yes, that TT has a phono preamp built in. There is a "phono/line" switch on the back. Set it to "Phono" to bypass the built-in preamp and use the Eros instead. (Set it to "Line" to direct connect the TT to the S.E.X. amp. See the downloadable manual on page 8.)

That seems a little backward. Shouldn't the switch in the "phono" position mean the preamp (with RIAA correction) is engaged. And when in the "line" position, just the unaltered signal (no RIAA) which would then require an external phono preamp?

These labels can indeed be confusing sometimes. If indeed that is the way, I too would have done it the same way as David. But, yeah the manual is  usually (but not always)  the correct way.