Glory hole overdrive need a mod ?

[niko_02]

Hello, just finished the Glory hole overdrive build, i'm a bit disapointed by the sound it produce especially by the fact that there always the clean signal to be heard mixed with the overdrive signal, for me I hear 50/50% of them.
At first I thinked I maked a mistake and verified all components values, they where all good.
By viewing some videos I understand that it's normal and it's come from how the bluesebreaker circuit is built.
There is an other thread here where I find that R7 determine the amont of gain, and I deduct in a brian wampler video that R6 6,8k affect the amount of clean signal passing through, can someone confirm me this R6 can solve that I dont like on this glory hole ?
Thanks

 

[Feral Feline]

How I would interpret R6 and R7...

The latter, R7 as you noted, is what's determining the overall gain of IC1.2.

R6, I'd hesitate to say it would "affect the amount of clean signal passing through"; rather I would say
it is affecting how much the signal gets distorted by D1–D4.

Really, it's R7 that is passing clean signal, but you mess with R7 and you mess with the overall gain of IC1.2 — which may not be desirable.


My suggested solution is to either replace R6 with a jumper or with a 5k trimmer (or 10k if you want to be able to have the stock 6k8 ever again, which I'm guessing you don't/won't). Get one of these handy little TRIMMIT! daughter-boards in the PedalPCB Shop:

...and replace R6 with the aforementioned 5k (or 10k) trimmer, that way you'll be able to dial in the amount of clipping going through with minimal surgery and circuit-tampering.

 

[Locrian99]

View attachment 46468

How I would interpret R6 and R7...

The latter, R7 as you noted, is what's determining the overall gain of IC1.2.

R6, I'd hesitate to say it would "affect the amount of clean signal passing through"; rather I would say
it is affecting how much the signal gets distorted by D1–D4.

Really, it's R7 that is passing clean signal, but you mess with R7 and you mess with the overall gain of IC1.2 — which may not be desirable.


My suggested solution is to either replace R6 with a jumper or with a 5k trimmer (or 10k if you want to be able to have the stock 6k8 ever again, which I'm guessing you don't/won't). Get one of these handy little TRIMMIT! daughter-boards in the PedalPCB Shop:

...and replace R6 with the aforementioned 5k (or 10k) trimmer, that way you'll be able to dial in the amount of clipping going through with minimal surgery and circuit-tampering.

I’ve played with this on a breadboard and switched values used a 10k pot etc and will confirm r6 varies the amount of clean signal. Just my 2 cents and everyone has different opinions, I felt that leaving it stock was better as it gave this pedal its signature sound. If I wanted to eliminate it and have a low gain overdrive I feel like there are better options like the chop shop comes to mind. But yes as mentioned you’re on the right track with r6.

 

[Feral Feline]

I’ve played with this on a breadboard and switched values used a 10k pot etc and will confirm r6 varies the amount of clean signal. Just my 2 cents and everyone has different opinions, I felt that leaving it stock was better as it gave this pedal its signature sound. If I wanted to eliminate it and have a low gain overdrive I feel like there are better options like the chop shop comes to mind. But yes as mentioned you’re on the right track with r6.

It varies the amount of clean signal by limiting the amount of clipping being bled through.

Saying R6 varies the clean signal is like saying the gas pedal in a car controls how slow you go, which is true. The less you press on the gas, the slower you'll go.

 

[eh là bas ma]

Before modding the circuit, you can try a volume booster before, like the SHO, or an other overdrive, and use the Glory Hole as a kind of preamp.
Your problem might be solved if the guitar signal isn't clean when it gets into the Glory Hole.

I mean, having lots of clean in the final signal can be an advantage, depending on how you use the circuit. With a chorus or some kind of modulation before, it could be better to use a circuit like yours, that doesn't color the sound too much.

You don't like how this circuit sounds alone, but maybe you will like it in a combo.

Be that as it may, if you really want to mod a Morning Glory, i'd suggest to have a look at Delyk's clone, which is a Morning Glory with several interesting mods (bass boost toggle, clipping and hard-clipping options) :

https://www.delykpcb.com/product/el-rey-de-la-gloria-azul-pcb/?attachment_id=1064&download_file=5c5b866ab67ba

You'll just have to compare both schematics to know how to add the mods.

 

[Locrian99]

I’ve played with this on a breadboard and switched values used a 10k pot etc and will confirm r6 varies the amount of clean signal. Just my 2 cents and everyone has different opinions, I felt that leaving it stock was better as it gave this pedal its signature sound. If I wanted to eliminate it and have a low gain overdrive I feel like there are better options like the chop shop comes to mind. But yes as mentioned you’re on the right track with r6.

It varies the amount of clean signal by limiting the amount of clipping being bled through.

Saying R6 varies the clean signal is like saying the gas pedal in a car controls how slow you go, which is true. The less you press on the gas, the slower you'll go.

Splitting a few hairs here. Might be interesting to set up an on off on dpdt you could just run a 6.8k across the middle with pout doing the math a 3.9kish to get in the realm of 3.4K and a jumper across the bottom to eliminate it. So you can change the amount of clipping bleed through as the wild cat apparently prefers

 

[Feral Feline]

Loc’99 — You have played with the circuit, whereas I have not. I was just spewing out how I perceive things, but without any 1st-hand experience on the breadboard or PCB itself. So I’ll just defer to your experience, and your switch-idea sounds great.

 

[Locrian99]

Loc’99 — You have played with the circuit, whereas I have not. I was just spewing out how I perceive things, but without any 1st-hand experience on the breadboard or PCB itself. So I’ll just defer to your experience, and your switch-idea sounds great.

I was teasing whatever it’s called we get the idea of what it’s going to do.

 

[benny_profane]

disapointed by the sound it produce especially by the fact that there always the clean signal to be heard mixed with the overdrive signal, for me I hear 50/50% of them.

You might not like soft clipping in that case. Have you built a hard clipping circuit that you like better?

 

[Feral Feline]

Potatoe
Puhtahtoh

 

[niko_02]

Hi, thanks for all this ideas, I will try differents values for R6 to ear the differences, maybe also increase R7 which I see in an other thread that seems to be the gain mod on the original morning glory v4.
I also have soft clipping pedals that I prefer, like my westwood overdrive clone which is on my board since few years now, I have never complain about this amount of clean signal like on this glory hole build.

 

[yazooligan]

I did a footswitchable high gain mod to my Glory Hole.

Glory Hole OD - Red Remote Gain Mod?

I want to add a high/low gain switch to my Glory Hole, and I've seen it done with toggle switches, but I'm wondering if anyone knows how to wire an input jack to use with my Red Remote to switch R7 between stock (220k) and 470k. Can this be done? Thanks! Here's a reference image (not my build!)...

forum.pedalpcb.com