Vintage Fenders with no mid control

[caspersvapors]

i.e. the pro, deluxe and princeton.

simple question really- if we were to imagine these did have a mid control - what would it be set at?

 

[JDJ]

About 6800 ohms?

 

[Tomo]

About 6800 ohms?

That sounds right.

I love Vol, Treble and Bass. If sound isn't good then problem is my playing!

Tomo

 

[smolder]

Lifting th 6.8k resistor from the back of the bass pot to a 25k pot and then to ground will give you a mid control. I've done it to a couple of sf and bf fenders. The hole where the useless polarit switch resides is a great (& reversible) location.

 

[hasserl]

Stock Mid pot value is 10k audio taper, stock mid resistor value in amps without mid pot is 6k8. Which means it is set to around 8-9 on a typical Fender knob.

 

[RCCola]

I definitely like my added mid pot on my 67 Deluxe Reverb. Allows me to get some fatter tones at high volume. When I play low volume, I put the mid pot at 0 which is like just having the resistor. I don't recall which pot value I used.

My mid pot/knob is in the front though. There was already a hole there when I got the amp. I wouldn't drill a vintage faceplate/chassis, obviously.

 

[erksin]

I don't know why you'd need one - when the amp is set to breakup, you have to dial back the bass and treble to keep it from getting too flabby and fizzy. The mids come to the fore at that point.

 

[hasserl]

...When I play low volume, I put the mid pot at 0 which is like just having the resistor. I don't recall which pot value I used.

...

No, with the pot at 0 is not the same as just having a resistor, it is like having no resistor at all, no resistance at all.

A 10k Mid pot allows slightly more mids or a lot less than just having a resistor. Mostly it allows you to scoop the tone more. However, you have much the same control over mids with just a Bass and Treble control; for more mids keep the Bass and Treble down low; for less mids/more scoop, crank the Bass and Treble.

 

[smolder]

No, with the pot at 0 is not the same as just having a resistor, it is like having no resistor at all, no resistance at all.

A 10k Mid pot allows slightly more mids or a lot less than just having a resistor. Mostly it allows you to scoop the tone more. However, you have much the same control over mids with just a Bass and Treble control; for more mids keep the Bass and Treble down low; for less mids/more scoop, crank the Bass and Treble.

Which is why the 25k is a decent option. You can push the mids a lot and get more thickness and a bit of growl. Almost a marshally tone.

 

[riker4208]

hey guys, my amp has a "soul control" in the polarity spot. I believe it's negative feedback control, is this completely different than mod Smolder refers to above?

 

[hasserl]

hey guys, my amp has a "soul control" in the polarity spot. I believe it's negative feedback control, is this completely different than mod Smolder refers to above?

Yep, the Soul control adds resistance to the nfb circuit to reduce the amount of nfb for more growl and warmth.

 

[RCCola]

No, with the pot at 0 is not the same as just having a resistor, it is like having no resistor at all, no resistance at all.

A 10k Mid pot allows slightly more mids or a lot less than just having a resistor. Mostly it allows you to scoop the tone more. However, you have much the same control over mids with just a Bass and Treble control; for more mids keep the Bass and Treble down low; for less mids/more scoop, crank the Bass and Treble.

A resistor in series with a pot that goes to ground with the pot on 0 takes the resistor out of the circuit?

I did what smolder describes. Maybe you thought I said I removed the resistor and replaced it with a pot? Not what I did - sorry, I wasn't clear. The mod smolder describes is the de facto mid pot mod, so I thought it was implicit.

(I also changed the 0.047 and 0.1 signal caps to 0.022 to alleviate some of the fartiness at high volume)

 

[Jacobpaul81]

That sounds right.

I love Vol, Treble and Bass. If sound isn't good then problem is my playing!

Tomo

Me Too. Too many controls = Too many variables.

I don't know why you'd need one - when the amp is set to breakup, you have to dial back the bass and treble to keep it from getting too flabby and fizzy. The mids come to the fore at that point.

+1

 

[Roe]

I use 25k and 100KA pots myself

 

[RCCola]

I don't know why you'd need one - when the amp is set to breakup, you have to dial back the bass and treble to keep it from getting too flabby and fizzy. The mids come to the fore at that point.

Yeah, why would anyone want more tonal variety?

 

[meterman]

Back when I had my '71 Super Reverb I had a tech bump the midrange resistor on the Ch.1 Normal channel way up, I think he ended up on 68k (10x the normal value). The result was cool, lots of extra mids and gain and grind, even feedback at low volumes on that channel, and of course I left the Ch.2 Reverb channel alone. The result was effectively turning it into a channel switcher with an A/B box, kinda cool. The one drawback was that with the mids up that high on Ch.1 the tone control became totally ineffective. Totally reversible BTW....

 

[semi-hollowbody]

That sounds right.

I love Vol, Treble and Bass. If sound isn't good then problem is my playing!

Tomo

not true...I have a drri and a couple other tube amps WITH mid pots and I can get better clean tone from them...at least the tone I want...if I set my DRRI treble and bass LOW, I can get a decent tone, but I use an eq pedal to tweak the mids...my bass abd treble sliders are basically flat,,,

If the drri had mid pot I wouldnt need an eq pedal...conversely I cant use my drri WITHOUT an eq pedal...my HRDX and classic 30 I can...

 

[hasserl]

not true...I have a drri and a couple other tube amps WITH mid pots and I can get better clean tone from them...at least the tone I want...if I set my DRRI treble and bass LOW, I can get a decent tone, but I use an eq pedal to tweak the mids...my bass abd treble sliders are basically flat,,,

If the drri had mid pot I wouldnt need an eq pedal...conversely I cant use my drri WITHOUT an eq pedal...my HRDX and classic 30 I can...

If you want more mids turn the Bass and Treb down and the Vol up. If you want less mids do the opposite, Bass and Treble up and Vol down.

Tomo? Dude knows what he's talking about. He's the kind of guy you don't argue with, you step back and think about what he's saying.

 

[MstrBones]

Tomo? Dude knows what he's talking about.

And then some...

 

[erksin]

Yeah, why would anyone want more tonal variety?

Then get a Boogie.

I never understand why people want to mod perfectly good vintage amplifiers - if you don't like how it sounds, I'd submit its not the right amp for you.