Another 124 build

[BobW]

Here's a list of my deviations from the #124 build:

1. Paralleled resistors on the B+4 and B+5 to give 200 VDC +/- 5 at V1a/b, V2a/b.

2. No death cap, gnd switch installed but not wired.

3. No Vdoubler, used full bridge (funks board), and used 7805 regulator.

4. No MV cap (15pF) Probably will add this in.

5. SPDT bright switch w/ 100pf, none, or 270pF.

6.Suppressor grids are 1k, 5W. (not 470 2W) may use EL-34 as an option.

7. Tube sockets wired to accept 6L6 or EL-34 (1&8 tied to gnd)

8. PI with 100k/110k and 10k trimmer (not 110/120, 5k trimmer)


Sound clips coming soon. First, I need to build my cab this weekend.

[BobW]

The MV cap installed, 15pF really helped the high's at lower volumes.

[BobW]

question was probably answered in the past, but what is a good setting (Rvalue to ground) for the 100K OD trimmer?

[heisthl]

A rule of thumb is 40% (40k to ground) I like 50% for single coils, bear in mind this adjustment is very dependent on the preamp volume setting. I usually set that to noon before I make the entrance adjustment.

[joebob]

What are the dimensions of the main board?

Dave

[joebob]

What are the dimensions of the main board and cap board?

Dave

[BobW]

thanks Henry!

[BobW]

Pics of my finished cab. Sound clips to follow, soon.

btw, except for the Volume (5-7) and Master Vol (2 bedroom -7 max club),
pic HPIM0882 is how I like to set the front panel controls.

[ic-racer]

Interesting how just a few circuit changes affect things. My controls are quite a bit different from what you are showing. I suspect with the 350k trimmer set 100k to ground changes the sweet spot for Volume and Drive. And my Ratio is low because of the 100k pot.

Now that I look closer I see you have Mid ON and JAZZ. Interested in hearing the clips.

Nice final pictures.

[BobW]

Ic, How different are your controls set? Your final pics look great too!

[ic-racer]

Ic, How different are your controls set? Your final pics look great too!

I was looking mostly at the Volume and Level/Drive.

Just based on those pictures is see whereas my sweet spot on the Voume is 3-5, I see yours is higher (5-7). I have much more definition around 3 or 4. The gain is still good that low because of where the OD trimer is set. What I mean by 'more definition' is that I get the effect I am hearing both the clean signal and distorted signal mixed together.

It looks like my Level (Drive) is lower than yours also. My theory here is I have 100k to ground on the OD trimmer where you probably only have 40k to 60k to ground. So I have more signal passing through. Though I'm certainly open to other explanations.