C4S Board orientation

[Noskipallwd]

Hello, I was wondering if there was a functional reason for the C4S boards being oriented 180 degrees in relationship to each other. I am installing some new caps,(larger) and it would be easier if I could have both of the boards B side pointing out. Is this okay?

Cheers,
Shawn

 

[Noskipallwd]

Hello, can anyone help a brother out?

Cheers,
Shawn

 

[Doc B]

Sure you can turn them either way as long as parts are stuffed in the board and the connecting leads stay connected to the proper terminals and solder pads exactly as specified in the manual. This might mean having to make some new leads to accommodate the different distances from PC board pads to chassis terminals.

 

[Paul Joppa]

It's been a few years and I don't remember the details, but yes there was a reason for this choice. Probably shorter wires. The tube sockets are not mirrored, but much of the circuitry is (since the second stage is in the middle). I remember spending a lot of time and frustration laying it out to minimize loop area and wire lengths (both of which are potential hum sources).

Pretty much all of our stereo amps have similar issues.  :^)

 

[Noskipallwd]

Thanks Doc. An Paul. That's what I was worried about, doing something to induce hum. Maybe I should put the caps on stand-offs, less change to the layout that way.

Cheers,
Shawn

 

[Grainger49]

Shawn,

Which caps are you changing?

 

[Noskipallwd]

Hey Grainger, I'm trying a pair of Clarity Cap MR series in the output, they are close to double the size of the Mundorfs. It was already cramped in that area as is, the Clarity caps would not fit well. I just finished installing them, I mounted them on 2" nylon stand offs. The eros is up and running, still quiet, caps still need some break in, but sounds pretty darn good. I just did not want to add any noise so I was agonizing over how to install the caps. Also replaced the 47K and 75K resistors with TC Vishay nudes. Saving my pennies for a Stereomour next.

Cheers,
Shawn

 

[Grainger49]

Shawn,

I had a Bit** of a time swapping my stock Solens for the Mundorf caps.  If I had thought about It I would have brought the STP to a terminal strip and terminated the output of the Mundorfs to the RCA jacks and the inputs to the terminal strips.  Big caps sound good but are a booger to shoe horn in.

Since I have misplaced my flash drive with manuals, and the upstairs desktop has the power supply burned out, I can't look at the schematic.  Which 47k resistor did you change, the input?  And which 75k did you replace?  The only one I remember is like a 2W.

 

[Noskipallwd]

Hey Grainger, the blue Clarity caps are pretty big, I really like the way they sound though. There are 2 sets of 47k, the 2 metal film 1/8w I replaced with vishays, the 2w I replaced with Amtrans carbon films. The 1/2w carbon film 75k resistors were replaced with vishays and the 10.5k metal films I replaced with tantalums. Don't know if this was worth the expense though but what the heck.

Cheers,
Shawn