Benson Monarch

[Synchu]

Looked into it on the world wide webs - sounds and looks very nice.
Great Aaron! I will be definitely looking to see the tracing results
Niki

[bobshbob1]

Have one of these on the bench at the moment. Just finished tracing it. This one has a paraphrase inverter.

Thanks,
Aaron

What a coincidence, I have one on my bench at the moment as well! I think there is a wiring mistake in this one though - perhaps you could help me confirm.

The plate resistor for the second stage is only 10k, and it's also connected to a 100k resistor that goes nowhere... There is a 0.1u cap going from the junction of those two resistors to the next tube's grid.

It still works as is but seems excessively noisy. I'm thinking it's supposed to be a 100k/10k split plate load, with the 100k going to pin 1 and the output signal taken from the 100k/10k junction. Is that what it is in your Monarch?

Thanks in advance!

[Aaron]

What a coincidence, I have one on my bench at the moment as well! I think there is a wiring mistake in this one though - perhaps you could help me confirm.

The plate resistor for the second stage is only 10k, and it's also connected to a 100k resistor that goes nowhere... There is a 0.1u cap going from the junction of those two resistors to the next tube's grid.

It still works as is but seems excessively noisy. I'm thinking it's supposed to be a 100k/10k split plate load, with the 100k going to pin 1 and the output signal taken from the 100k/10k junction. Is that what it is in your Monarch?

Thanks in advance!

This is what I traced. This one had an issue with the DC heaters.

Thanks,
Aaron

[bobshbob1]

This is what I traced. This one had an issue with the DC heaters.

Thanks,
Aaron

Nice, thank you! That's what I thought it should be, guess this was a wiring error from the factory.

[shane]

Any chance we'll be seeing the rest of that schematic Aaron

[turbofeedus]

+1 for seeing the schematic, I wanna see what the hype is all about.
Going out on a limb and guessing it probably some resistors and capacitors. Maybe a potentiometer or two.

[Aaron]

I haven't measured voltages yet, but this is for anyone who needs a schematic for repairs or servicing.
And the Dizzy Bird reverb unit.

Thanks,
Aaron

EDIT: revised schematic with voltages

[Aaron]

Just realised I didn't do the DC heaters and didn't finish doing the rectifier in the Monarch. Will update once I've finished it.

[Synchu]

Great Aaron,
Many thanks for your effort. Looks good.
Looking at it - seems that 5E3 PT/OT should do the job.

Niki

[shane]

Thanks Aaron that's really useful
What reverb tank are they using?

[bal704]

What is the value for the pot in the phase inverter?

[turbofeedus]

Thanks Aaron!

What is the value for the pot in the phase inverter?

Wondering that myself, and the taper?

[dorrisant]

Thanks Aaron! Gonna build one of these... I have a Bogen CHA20 chassis without a cage around the shop somewhere.

[Colossal]

Thanks Aaron!

What is the value for the pot in the phase inverter?

Wondering that myself, and the taper?

I would guess 5-10k and linear

[frankdrebin]

I haven't measured voltages yet, but this is for anyone who needs a schematic for repairs or servicing.
And the Dizzy Bird reverb unit.

Thanks,
Aaron

looking at the Monarch schematic,if you bring down to zero the reverb pot you get zero volume,i guess there should be a resistor in line.
The Vinny model is exactly like the Dizzy without the reverb part.