DSL40C preamp slots

[solarburn]

What preamp slot effects the green/crunch? What preamp slot effects the red channel?

I know V3 is the cascade follower and V4 is the PI.

I'm tube rolling with V1 and V2 and am not sure what slot effects the green crunch gain and what tube position runs the red channel? Right now I have a 12AX7 in V1 and 12AT7 in V2.

Trying to save myself from a lot of in/out tube socket wear.

Thanks for any clarification!!!

 

[KraftyBob]

The only difference between the green channel and red channel is the red channel goes through V1B and green does not. The Green channel goes through V1A, then to V2.

Here's the signal path for V1 & V2...

 

[PelliX]

I'm tube rolling with V1 and V2 and am not sure what slot effects the green crunch gain and what tube position runs the red channel? Right now I have a 12AX7 in V1 and 12AT7 in V2.

Trying to save myself from a lot of in/out tube socket wear.

Thanks for any clarification!!!

Yup, V2 is common, V1B is specific to the Red channel. See the schematic, it's fairly straightforward.

If you're looking to *tame* the Red channel and decrease a bit of compression there, you might want to try an EC832 (AKA "12DW7", but both are just JJ naming conventions). It's half ECC83 (12AX7 in the States) and half ECC82.

JJ Electronic - ECC832 - 12DW7

JJ Electronic - Vacuum tubes, Capacitors, Amplifiers

www.jj-electronic.com

EDIT: Ugh, attachment is too large, here's a link for the schematic: https://music-electronics-forum.com/filedata/fetch?id=837569

 

[jeffb]

IOW, Green crunch is affected by both V1 and V2.

I'm not a tech, so I have to speak in "sound" but I rolled a gazillion tubes in mine and IME V1 slot helps determine overall amount of gain on Green crunch, and the general tonality and what you put in V2 either adds muscle or thins it out...Bolder/Weaker, if you will.

 

[solarburn]

Yup, V2 is common, V1B is specific to the Red channel. See the schematic, it's fairly straightforward.

If you're looking to *tame* the Red channel and decrease a bit of compression there, you might want to try an EC832 (AKA "12DW7", but both are just JJ naming conventions). It's half ECC83 (12AX7 in the States) and half ECC82.

JJ Electronic - ECC832 - 12DW7

JJ Electronic - Vacuum tubes, Capacitors, Amplifiers

www.jj-electronic.com

EDIT: Ugh, attachment is too large, here's a link for the schematic: https://music-electronics-forum.com/filedata/fetch?id=837569

Thanks PelliX! Yeah I have a 832 and used it quite some time ago. Was prolly you that caught my attention about it. I remember it being useable but at the time I kept rolling. Then I gave it a rest. I think I'm at another tuning stage where I'm focussing mostly on the green crunch instead of Lead 2.

I'm finding the new mint late sixties RFT AT7 sounds better in V2 with a RFT 12AX7 in V1 on the green crunch. Vise versa not so much. This AT7 makes notes seem a bit rounder yet can exhibit some bite when digging in. Fuller yet less saturated.

So why I wondered what preamp slot effected the green channel or side of preamp tube mostly between V1 & V2.

 

[solarburn]

The only difference between the green channel and red channel is the red channel goes through V1B and green does not. The Green channel goes through V1A, then to V2.

Here's the signal path for V1 & V2... View attachment 126481

Thank you KraftyBob!

 

[PelliX]

I think I'm at another tuning stage where I'm focussing mostly on the green crunch instead of Lead 2.

Best place to be on that amp, IMHO!

Also agree with what KraftyBob said about V1 determining the overall character; the following stages just ramp it up and/or compress the signal somewhat. After all, V1 is what initially translates the very weak signal from your guitar and turns it into something for the rest of the amp to 'process'.

 

[solarburn]

IOW, Green crunch is affected by both V1 and V2.

I'm not a tech, so I have to speak in "sound" but I rolled a gazillion tubes in mine and IME V1 slot helps determine overall amount of gain on Green crunch, and the general tonality and what you put in V2 either adds muscle or thins it out...Bolder/Weaker, if you will.

Thanks jeff! I'm liking the AT7 in V2 however the Red channel seems to be thinner both ways using this tube combo. It's interesting.

I've got a V30 in it right now. I could put my Gold back in and get fuller across the board but I wanted to tune with the V30. I like what it does for the green crunch channel. Don't think I should worry about the Red channel anyways as I am focussing on using the green crunch with my OD pedals.

 

[junk notes]

Appears that I am in agreement with this bunch. The red gain got to be over the top when I had the combo and probably would have benefited better to my liking's by trying out an AT7 loosing some the sizzle.

 

[solarburn]

Appears that I am in agreement with this bunch. The red gain got to be over the top when I had the combo and probably would have benefited better to my liking's by trying out an AT7 loosing some the sizzle.

And if neutered too much the Red side just gets brittle.

I'm messing with the PI now. Put a ole stock AT7 had in a box in there. Sounds alright. Just wanted to see if hitting the power section with it changed much. Usually I use a clean/neutral AX7.

 

[Mitchell Pearrow]

I did put a 12AT7 in V2
And a 5751 in V4
Greatly helped my red ultra 2 channel.
But didn’t seem to hamper the green crunch channel, but that was my roll out and I have been happy with this change for a little over 2 years now.
And I use the green crunch for a lead boost, by kicking the volume up a couple of notches from the red ultra 2 .

 

[Todd L]

The only difference between the green channel and red channel is the red channel goes through V1B and green does not. The Green channel goes through V1A, then to V2.

Here's the signal path for V1 & V2... View attachment 126481

I just put two 12AT7s in V1 and V2 of my DSL40c, solving the whole excessive gain problem on “ultra” channel. Exactly what I wanted, too bad I got the last two PM 12AT7 tubes at Andertons . They will get scarce.

 

[solarburn]

I just put two 12AT7s in V1 and V2 of my DSL40c, solving the whole excessive gain problem on “ultra” channel. Exactly what I wanted, too bad I got the last two PM 12AT7 tubes at Andertons . They will get scarce.

Cool deal. What is a PM AT7? I'll have to try that sometime see what it sounds like on the Red channel. I did use a 12AU7 and AT7 in V1 & V2 and it neutered the gain too much.

I like the RFT AT7 IN V2 and RCA AT7 IN the PI. I'm hanging out in the green crunch channel as I'm going to be running my Guv'Nor and a couple other pedals in front. So I haven't spent much time on the Red channel lately. I also put my Goldback speaker back in it since I'm doing midgain to hard rock stuff mostly. Giving a more old school saturation sound.

 

[TonalEuphoria]

Cool deal. What is a PM AT7? I'll have to try that sometime see what it sounds like on the Red channel. I did use a 12AU7 and AT7 in V1 & V2 and it neutered the gain too much.

I like the RFT AT7 IN V2 and RCA AT7 IN the PI. I'm hanging out in the green crunch channel as I'm going to be running my Guv'Nor and a couple other pedals in front. So I haven't spent much time on the Red channel lately. I also put my Goldback speaker back in it since I'm doing midgain to hard rock stuff mostly. Giving a more old school saturation sound.

Using a 12AU7 in V1 was enough for me playing hard and progressive rock myself, loving modern and old high gain, making old people cry tones. With 12AX7's in all other spots. Everything else neutered the gain too much. Right now I'm using a JJ 12AU7 in my V1 spot in my DSL20CR and Tung Sol 12AX7's in V2 and V3. It gives me the gain I love with good clarity and still with screaming sustain around 4.

 

[solarburn]

Using a 12AU7 in V1 was enough for me playing hard and progressive rock myself, loving modern and old high gain, making old people cry tones. With 12AX7's in all other spots. Everything else neutered the gain too much. Right now I'm using a JJ 12AU7 in my V1 spot in my DSL20CR and Tung Sol 12AX7's in V2 and V3. It gives me the gain I love with good clarity and still with screaming sustain around 4.

"Making old people cry tones"

I don't think I just used the 12AU7 in V1 with the rest 12AX7's. I may redo and see what I get. Get the cat to cry at least.

 

[TonalEuphoria]

"Making old people cry tones"

I don't think I just used the 12AU7 in V1 with the rest 12AX7's. I may redo and see what I get. Get the cat to cry at least.

If it's anything like mine, it's probably used to it and even appreciates the awesome tones.

 

[SkyMonkey]

If you're looking to *tame* the Red channel and decrease a bit of compression there, you might want to try an EC832 (AKA "12DW7", but both are just JJ naming conventions). It's half ECC83 (12AX7 in the States) and half ECC82.

According to the schematic I got off an MF thread (below), the pins for the Ultra (exclusive) side of V1 are 6, 7, 8.
The Classic (common) side uses only pins 1, 2, 3.
An ECC832 (as you linked to) has pins 1, 2, 3, as the x17 side of the dual triode.
So the Classic gets a gain reduction to x17 instead of x100.
The Ultra still gets both sides (x17 & x100).

To get a reduction on the Ultra only, you need the reverse of the ECC832: the ECC823.
That one has the x17 on the 6, 7, 8, side, so only the Ultra gets the gain reduction: x100 & x17 (they're reversed).
The Classic then gets the x100, which is the same as a normal ECC83.


See the note on the ECC823 at the bottom.

So, Now That The New Dsl Schematics Are Finally Out There...

... would it be possible for one of you technically oriented guys to tell us how different they are from the previous gen DSLs? To my (completely untrained) eyes the new (HR) preamp circuit seems quite similar to the older (H) one. One glaring difference is that the new one appears not to have...

www.marshallforum.com

 

[PelliX]

Yup, must have mixed the numbers while writing that, sorry for any confusion!

 

[SkyMonkey]

It is a pity it's that way around, because the ECC832 is a damn sight easier to find in Europe than an ECC823.
I had to ship mine to the UK from Denmark!

 

[TonalEuphoria]

I'm guessing you guys using ECC823's in V1 must like to have the Classic channel on crunch most of the time instead of having a cleaner clean sound in the classic side to use with a high gain Ultra channel. It's seems like a lot of players who play more classic rock tones like that.

I like both channels cleaned up which is why I prefer a 12AU7 in V1. Having a dedicated clean tone in the Classic channel and just the right amount of gain in the Ultra. That I can clean up with my volume control and boost volume and gain with an overdrive.