Dropping String Problems

[ToneMerc]

Verify that the OD entrance is referenced to ground as well and I would square away any layout issues first. I'm not sure of your layout, but you don't by chance have any of the locations transposed do you?

TM

[passfan]

Yes , ground is shared with cathode resistors as per 124 layout. Overdrive responds as well as I can tell having not had time to fiddle with it yet. It's only when I flip preamp boost to manual is when all **** breaks loose. here are pics

[ToneMerc]

It's hard to tell think there's something funky going with the way that the PAB relay is wired, looks like a connection is missing. Can you diagram it out?

TM

[passfan]

It is wired as per the 124 layout. It looks funny because I slipped my wires in from underneath as well as used two 10m's in series both there and at the pot. I didn't get 22M's from mouser. In forcing a look at the relays you've helped me to discover a wiring error. I have the switced leads from the back panel switches crossed to each relay. What I thought was the PAB was really the Overdrive. I have since nturned the overdrive trimmer down some and when I get a chance will set that up accordingly.

[passfan]

Okay, so now when I engage the overdrive I get control at the ratio and volume in the OD section. If I engage PAB while in overdrive I get a drop in gain. If I engage the mid boost while in overdrive, it is uncontrolable and fuzzy. The mid boost gives a huge jump in gain whenever it is engaged.

[passfan]

With the mid boost engaged and the overdrive off the PAB gives a gain increase when engaged. Any other time the PAB would cause the gain to drop when engaged. I'm not sure if any of this is proper and if not, could it be due to the single throw switches instead of the double throw ? Thanks to those attempting to wade through all this.

[ToneMerc]

Try this, at the R/J switch swap the connections at the middle terminals aka move the wire on the right to the left and vice versa. I may need you to clarify the relay terminal layout as well.

TM

[passfan]

Will do, although I will have to do it this evening. My honey do for the day must get done first or there will be no peace in my shop. Thanks for all

[ToneMerc]

My honey do for the day must get done first or there will be no peace in my shop. Thanks for all

Me too, she's been at me to take down the Christmas lights that she put up.

TM

[Structo]

Meh, just leave them up, that way you won't have to do it next Christmas.

BTW, my wife doesn't think that is funny as I am getting a look that can kill.

[passfan]

Sorted out my plate voltage problems and repaired my float switch in my sewage lift tank. Now to sort out the switch problems. I double checked my wiring on the R/J switch and it's correct. The diagram is per the 124 layout guide. They are wired to the common and n/c contact. If I power up with the mid switch down, the first time I switch it I get a big thump. The mid and R/J switch produce enough of a gain increase that I have to adjust volume. No way to switch back and forth without a big volume difference.


Oh yea... dummy me had a jumper installed under the 22k dropping resistor on the main filter board. I looked for it with a dental mirror because I could never get that node to move at all...even with a 100k resistance.

[Structo]

There is a big volume difference between the Jazz and Rock setting with Rock being the louder.

[passfan]

Okay then that one is normal. Now if in jazz mode I get that same volume jump if I switch the mid boost in. Is that normal ?

[Structo]

Not sure how big that jump is but it is called a midboost.
So if you used a .002uF and a 390pf for the midboost switch then that is correct and it will boost the volume.
When the two caps are in series you get a total of 326pf but when the midboost switch is on, it takes the 390pf cap out of circuit which leaves the .002uF.

I have the mid boost on my foot pedal and don't really find a use for it much.

[passfan]

Man... I love this thing. The bottom is so clear and detailed. I'm playing it with the bright , mid , and rock all on , preamp at around 8 and the higher the master goes the more excited I get. And, that's with a 2x12 loaded with Crate OEM 12's. Big difference between this and the Trainwreck's.