Finally.... My HRM likes my Fenders

[Fischerman]

That sounds really nice! Is that a 47pF cap in parallel with the 470k at the OD entrance? Your OD entrance looks like the 'low gain network' but I can't see the one resistor (obscured by the .002 coupler after V2a) and can't tell what the value of that small cap is (it's the same size as your 500pF treble cap so that's why I ask).

Are your grid stoppers on V2 the usual 68k and 150k (or 180k)?

Curious where all the extra volume in OD is coming from.

[stelligan]

That sounds really nice! Is that a 47pF cap in parallel with the 470k at the OD entrance?

Thanks Fischerman. Yes 47pf

Your OD entrance looks like the 'low gain network' but I can't see the one resistor (obscured by the .002 coupler after V2a) and can't tell what the value of that small cap is (it's the same size as your 500pF treble cap so that's why I ask).

200k resistor

Are your grid stoppers on V2 the usual 68k and 150k (or 180k)?

68k and 180k

Curious where all the extra volume in OD is coming from.

Me too! That amp is LOUD AS HELL with the OD on Rather fun actually, but kind of hard on the eardrums. Voltages are 212 at OD1 and 219 at OD2 with EH tubes- around 6 volts lower with JJ's. I am contemplating a resistor across that pot to make the travel more usable. I am open to suggestion. It's a 1M audio taper.

[dogears]

It should not be so loud. What resistance from ground is your pre-od trimmer??

Also, use the Dumbleator. Set it at 11 oclock on both pots. That will scrub some db.

Fwiw, my HRM amps clean channels (with boost) are a little louder than my OD when the masters are set the same!! My mids are at 6.45K I do have it tweaked for Bluesmaster and megaPAB.

[stelligan]

I closed the bugger up already! I knew I should leave it open as the suggestions came in I just need to make a nice cradle for these things! I'll make notes for when I go after it - again....

It should not be so loud. What resistance from ground is your pre-od trimmer??

Also, use the Dumbleator. Set it at 11 oclock on both pots. That will scrub some db.

Fwiw, my HRM amps clean channels (with boost) are a little louder than my OD when the masters are set the same!! My mids are at 6.45K I do have it tweaked for Bluesmaster and megaPAB.

I am able to get it set so that it works out for me - it just looks funny when I see those masters. The channel switching volumes match well as set and The Dumbleator is just a hair above unity as shown. This is a 50 watter.

[Fischerman]

Other than just reducing the value of the pot I'm not sure what is the best way to change that. Do you have the series 100k between the HRM stack and the OD Master?

EDIT: My amp is pretty close to 'balanced' between channels when both Masters are at the same setting. I usually run them both at around 6-6.5 and then set the (built-in) D'Lator Send control such that my effects get the right level...then use the D'Lator Return Level as my 'global' master.

[stelligan]

Other than just reducing the value of the pot I'm not sure what is the best way to change that. Do you have the series 100k between the HRM stack and the OD Master?

EDIT: My amp is pretty close to 'balanced' between channels when both Masters are at the same setting. I usually run them both at around 6-6.5 and then set the (built-in) D'Lator Send control such that my effects get the right level...then use the D'Lator Return Level as my 'global' master.

No 100k from the stack to the master - that may be the culprit? I use the Dumbleator return as a "master" as well when playing in the same room with the amp. When I record, I open it up and move to the next room

[dogears]

Add the 100K. Not only will it help the pot "taper", it effects the stack response, and it is accurate as every Dumble HRM I have checked out had it.

Other than just reducing the value of the pot I'm not sure what is the best way to change that. Do you have the series 100k between the HRM stack and the OD Master?

EDIT: My amp is pretty close to 'balanced' between channels when both Masters are at the same setting. I usually run them both at around 6-6.5 and then set the (built-in) D'Lator Send control such that my effects get the right level...then use the D'Lator Return Level as my 'global' master.

No 100k from the stack to the master - that may be the culprit? I use the Dumbleator return as a "master" as well when playing in the same room with the amp. When I record, I open it up and move to the next room

[ayan]

Add the 100K. Not only will it help the pot "taper", it effects the stack response, and it is accurate as every Dumble HRM I have checked out had it.

Agreed. However, it will not affect the volume per se. I am not sure what causes Stelligan's amp to be so loud in OD mode. My various HRM incarnations have always yielded an OD channel which is not as loud as the clean for same master settings.

Gil

[Fischerman]

In 'experiments' in the past I've found that it's the resistance to ground that makes all the difference in volume...the leftover series resistance of the pot has a relatively small effect. For example, you could probably lift the ground on your Master and that would give you pretty much max volume...regardless of where you set the Master (which would still have the series component connected). Obviously the rest of the circuit matters but if there's not much else to form a voltage divider then the resistance from wiper-to-ground is the biggie.

Having the mid trimmer ground lifted would obv cause a lot more signal there but then the stack wouldn't work. It really seems that the HRM stack loss would be a place to look. I can't remember the exact numbers but the output from V2b is pretty ginormous for a preamp...like in the 70vac range IIRC (at my 'normal' HRM settings using 100mV input signal).

But hey...it sounds great. That's what really matters.

[stelligan]

Thanks to everyone for the responses and suggestions. I will most definitely get a 100k in there - don't know how I missed that. Beyond that - it really ain't broke. I'm diggin' what I hear and that's the main thing. If I could just quit gawkin' at those masters.........

[dogears]

Where is your pre-od trim set from ground?? 22K to 25K is it for me.

Thanks to everyone for the responses and suggestions. I will most definitely get a 100k in there - don't know how I missed that. Beyond that - it really ain't broke. I'm diggin' what I hear and that's the main thing. If I could just quit gawkin' at those masters.........

[stelligan]

Where is your pre-od trim set from ground?? 22K to 25K is it for me.

Scott,

where would you approximate this 4.7k + 25k trimmer?

[skyboltone]

Where is your pre-od trim set from ground?? 22K to 25K is it for me.

Scott,

where would you approximate this 4.7k + 25k trimmer?

Metal oxide cathode bias resistor......who'd thunk. Mojo in motion.

[stelligan]

This is how the setup sounds going from:
Clean, to OD, to OD + PAB, to OD + PAB + Mid

http://www.jonesin.org/Dave/test.mp3

[stelligan]

duplicate post