The Official Marshall DSL40c Information Thread

[solarburn]

I am considering trying the EH 6ca7 power tubes. Also, the Genalex KT-77. I have read a number of threads concerning these, but few mentions of the DSL40C. Anyone here listening that can provide insight into what to expect. The 77s are way expensive. I would dislike spending over $200 with tax on a pair of tubes and not enjoying the result at all. The EH tubes can be had for under $100 with tax. I know that this can be subjective when it comes to tone, but I have used the opinions of others on this thread to make positive changes with my amp. Thanks.

my experience only in this amp:

no on the Genalex KT-77. For me was not a sonic upgrade in tone or feel. In any of my Marshalls. I spent the money and found the truth. Done.

EH 6CA7's- added articulation while soloing nice raw animalistic bottom end.lol Great power tubes. Have used in a few of my Marshallz now.

I play at volume. Only way I like this amp. It opens up when the power section comes on. Otherwise you're just hearing preamp. I still love playing this amp. Broke it out today after a long hiatus. Threw in a Veteran 30, dropped in the original 34's which hadn't seen much play time and of course a rebias at 34mv. Tits! The fuker sounds and feels great. Only reason I put a different speaker in is I'm playing musical 12's in my Iconic 412. Don't like the 412 stocker's any more. Too smooth for me.

Daem if it ain't the heaviest combo I've owned! I originally bought it for an easy grab and go jam amp. Boy was I overestimating my strength.

 

[CSM746]

I converted my DSL40C to a Stagecraft cab head a while back....sure saves the back Solarburn. I ordered a set of 6CA7 tubes from the Tubestore and installed them. The tubes were marked as matched at "60". The tube installed on the right side (looking at the back) glowed much brighter than the left when the amp was fired up. I have two Eurotubes Bias Pro probes which also show wattage so this is somewhat easy. It was at 62 mA and using the full swing on the trim pot I could get it down to 44. The left tube started out in the 33 mA range and easily went to 44. The wall voltage here is between 123 and 125 depending on the day. Using a Brown Box I reduced it to 119 before installing these tubes. I will leave out some detail but the only way I could get these tubes down to 38 was to reduce the voltage to 116. The plate voltage at 119 was 442 and at 116 was 434.

I wrote Jon at the Tubestore who was helpful and responded with "This is not uncommon with 6CA7 tubes, especially from EHX. Although compatible with EL34 circuits they typically need more bias voltage and not all EL34 amp builders have enough in the stock bias circuit. Other EL34 tubes you would have from us will likely be rated much lower and therefore normally bias without circuit mods required, just rebiasing. The simple fix here is to just change the bias resistor to squeeze out a few more volts, allowing you to get the bias in the range you prefer. Looking at the schematic, I'd start by reducing the dropping resistor R106 to 10K or something and compare it to the stock bias output. You could change resistors R92,93 and R97, R98, but then you're doing twice as many and R106 might get it solved with less changes."

Being concerned about the possibility of returning to EL34 tubes after the dropping resistor mod and after reading up on this I asked about tubes matched at "50". The response was that these tubes would have less natural current draw and therefore probably bias up nicely at 38 mA where I wanted them. This is at about 68% dissipation. I ordered them up and installing them again with the same relative plate voltage the tubes dialed in with perfect 38 bias and in the middle range of the trim pots. So, lesson to self and to share with ya'll, the matching of tubes plays a part here. Now I have a set of 6CA7 tubes that probably would work with higher plate voltage, but of no use now other than looking nice in the drawer.

The first set I felt sounded full and good to my ear. An improvement over EL34B STR I feel. But, if they drifted, I had nothing left of the trim pot in the future. I have only played the latest set of tubes for about 15 minutes, but they sound great. I will continue to play for a few days with different speaker cabs and flesh this out in terms of what impact I feel the shift to using 6CA7 tubes make.

 

[solarburn]

I converted my DSL40C to a Stagecraft cab head a while back....sure saves the back Solarburn. I ordered a set of 6CA7 tubes from the Tubestore and installed them. The tubes were marked as matched at "60". The tube installed on the right side (looking at the back) glowed much brighter than the left when the amp was fired up. I have two Eurotubes Bias Pro probes which also show wattage so this is somewhat easy. It was at 62 mA and using the full swing on the trim pot I could get it down to 44. The left tube started out in the 33 mA range and easily went to 44. The wall voltage here is between 123 and 125 depending on the day. Using a Brown Box I reduced it to 119 before installing these tubes. I will leave out some detail but the only way I could get these tubes down to 38 was to reduce the voltage to 116. The plate voltage at 119 was 442 and at 116 was 434.

I wrote Jon at the Tubestore who was helpful and responded with "This is not uncommon with 6CA7 tubes, especially from EHX. Although compatible with EL34 circuits they typically need more bias voltage and not all EL34 amp builders have enough in the stock bias circuit. Other EL34 tubes you would have from us will likely be rated much lower and therefore normally bias without circuit mods required, just rebiasing. The simple fix here is to just change the bias resistor to squeeze out a few more volts, allowing you to get the bias in the range you prefer. Looking at the schematic, I'd start by reducing the dropping resistor R106 to 10K or something and compare it to the stock bias output. You could change resistors R92,93 and R97, R98, but then you're doing twice as many and R106 might get it solved with less changes."

Being concerned about the possibility of returning to EL34 tubes atter the dropping resistor mod and after reading up on this I asked about tubes matched at "50". The response was that these tubes would have less natural current draw and therefore probably bias up nicely at 38 mA where I wanted them. This is at about 68% dissipation. I ordered them up and installing them again with the same relative plate voltage the tubes dialed in with perfect 38 bias and in the middle range of the trim pots. So, lesson to self and to share with ya'll, the matching of tubes plays a part here. Now I have a set of 6CA7 tubes that probably would work with higher plate voltage, but of no use now other than looking nice in the drawer.

The first set I felt sounded full and good to my ear. An improvement over EL34B STR I feel. But, if they drifted, I had nothing left of the trim pot in the future. I have only played the latest set of tubes for about 15 minutes, but they sound great. I will continue to play for a few days with different speaker cabs and flesh this out in terms of what impact I feel the shift to using 6CA7 tubes make.

So far with both EH & JJ 6CA7'S I've been able to bias at 34mv with room to spare. That's running 120V at wall and PV around 450'ish. The Origin 50 at 33mv had a PV of 444V. I have biased to 70% dissipation with good results. Depends on the tubes. My wall voltage seems to stay at 120V every time I meter it.

I've had EL34's bias too hot where I couldn't get them under 40mv. It does matter from tube to tube set. Had drift issues with some too. If I remember right it happened to a pair of EH 6CA7'S years ago. The EH's have been solid otherwise since. No repeats with them but it can happen to any tube/set.

Looks like you have a solid idea of what you need and how to run voltage changes. I use a variac from time to time to decrease wall flow.

 

[end user]

I know I am just beating a dead horse but 533 pages? Well time for a refresher I guess. There is a happy medium with this amp between the 2 channels. I am achieving it easily right now and below are my settings. BTW this is at band volume and in a treated 20x20 room. Amp is on a angled stand pointed at my head. Roughly seeing 96-98db at 5ft or so.

Classic Gain
Crunch button: in
Gain: 12 'oclock
Volume: 10:30'ish

Ultra Gain
Lead 1 (button out)
Gain: 10:30'ish

EQ's and Reverbs

Treble: 8 o'clock
Mid: dimed
Bass: 11 o'clock
Tone shift: Off (button out)
Presence: 10 o'clock
Resonance: 10 o'clock
Both Reverbs at 11 o'clock

With these settings Classic gain easily functions for clean and low-mid gains and Ultra Channel can be used either for higher gains and/or soloing.

I am a rock player mostly so adjust gains as need for heavier stuff. My amp is stock except for the new Mullard power tubes I just installed and biased the amp at 38.5 on both sides.

 

[solarburn]

I know I am just beating a dead horse but 533 pages? Well time for a refresher I guess. There is a happy medium with this amp between the 2 channels. I am achieving it easily right now and below are my settings. BTW this is at band volume and in a treated 20x20 room. Amp is on a angled stand pointed at my head. Roughly seeing 96-98db at 5ft or so.

Classic Gain
Crunch button: in
Gain: 12 'oclock
Volume: 10:30'ish

Ultra Gain
Lead 1 (button out)
Gain: 10:30'ish

EQ's and Reverbs

Treble: 8 o'clock
Mid: dimed
Bass: 11 o'clock
Tone shift: Off (button out)
Presence: 10 o'clock
Resonance: 10 o'clock
Both Reverbs at 11 o'clock

With these settings Classic gain easily functions for clean and low-mid gains and Ultra Channel can be used either for higher gains and/or soloing.

I am a rock player mostly so adjust gains as need for heavier stuff. My amp is stock except for the new Mullard power tubes I just installed and biased the amp at 38.5 on both sides.

Cool share on the settings and bias number. You said your amp is stock(excluding PT's)so it still has the 70/80 speaker? Curious.

I'm gonna play with a couple speaker changes while I'm off work(vacation). A EV12L BL and V30. Just to see. I really want to put in a 12 H Anniversary even though it's rated at 30 watts. I'm speculating a good result other than a blown speaker. That's on hold until I can get another one anyways.

I'll give your settings a try while I'm playing with the amp.

 

[Screamin Willie]

Cool share on the settings and bias number. You said your amp is stock(excluding PT's)so it still has the 70/80 speaker? Curious.

I'm gonna play with a couple speaker changes while I'm off work(vacation). A EV12L BL and V30. Just to see. I really want to put in a 12 H Anniversary even though it's rated at 30 watts. I'm speculating a good result other than a blown speaker. That's on hold until I can get another one anyways.

I'll give your settings a try while I'm playing with the amp.

I love a V30, but I must say the V-Type that came stock in my DSL40CR is a great speaker. Really liking that one also.

 

[solarburn]

I love a V30, but I must say the V-Type that came stock in my DSL40CR is a great speaker. Really liking that one also.

I've tried that one too. Not bad. I actually don't mind the stock 70/80 when broken in that came in mine.

Really curious how the Electrovoice will translate the classic to Lead channels. Wouldn't be crazy about the weight gain added to an already heavy combo.

 

[end user]

You said your amp is stock(excluding PT's)so it still has the 70/80 speaker?

Yep. I was all ready to start experimenting with some speakers I have laying around like V30, ET65, and an Egnater Elite 50 (supposed to be a 50w Greenback) but I am liking this so much "as is" I dont want to mess with it. I am doing my first gig with it tonight. I figure that's the real test and if I don't like how it sounds at the gig, I will start swapping in some different speakers starting with the V30.

 

[solarburn]

Yep. I was all ready to start experimenting with some speakers I have laying around like V30, ET65, and an Egnater Elite 50 (supposed to be a 50w Greenback) but I am liking this so much "as is" I dont want to mess with it. I am doing my first gig with it tonight. I figure that's the real test and if I don't like how it sounds at the gig, I will start swapping in some different speakers starting with the V30.

Yah I like the 70/80 in mine. Others really don't however my guitars/pups work good with it and like you I play rock and hard rock mostly. Look forward to what you find playing out live.

Just got done doing the V30 and EV12L. I have the Electrovoice in a separate oversized 112 cab. So V30 in DSL was good. I just did one setting on the Red channel on both. Hard rock tone. Clean up easily had.

Both had their pros/cons. Neither made me go "Oh that's nice it's going in now" but they sound/felt good. So did my Veteran 30 and Eminence GB128. Solid performers.

So if my speculation is accurate the 12H 30 Anni just might excite my rock to hard rock desires most. Don't have one here but will soon.

 

[end user]

I've tried that one too. Not bad. I actually don't mind the stock 70/80 when broken in that came in mine.

One thing I noticed at my gig yesterday was how the 70/80 really needs to be pushed to sound good. It's not just the amp, it's the combination of the amp and speaker being less efficient that gets you to that sweet spot. It makes sense because the DSL40c, unless it's completely cranked doesn't really do power tube breakup and it sounds sweet long before it gets cranked, but does need to be loud.

That points to the speaker. So after all I think I will swap in some different ones to see if I can get to that sweet spot earlier on the volume dial because most venues out here I won't be able to get there with the way the amp is right now. Needs to be very loud and thats not tolerated around here unfortunately.

 

[solarburn]

One thing I noticed at my gig yesterday was how the 70/80 really needs to be pushed to sound good. It's not just the amp, it's the combination of the amp and speaker being less efficient that gets you to that sweet spot. It makes sense because the DSL40c, unless it's completely cranked doesn't really do power tube breakup and it sounds sweet long before it gets cranked, but does need to be loud.

That points to the speaker. So after all I think I will swap in some different ones to see if I can get to that sweet spot earlier on the volume dial because most venues out here I won't be able to get there with the way the amp is right now. Needs to be very loud and thats not tolerated around here unfortunately.

Yah and I usually keep volume right around noon on mine. Maybe others are finding it raspy at lower volumes. I do like the amp more when enough power section is introduced. Playing live can really limit that setting though for sure.

I jammed on the V30 and Electrovoice again. Think I prefer the V30 for the mids and the Electrovoice for the bottom end. So I could go either or otherwise with them. Backing off on guitar volume/tone was great for both. Cool in betweens. The V30 had a bit more of the snap and sting of upper kerrang though the Electrovoice has some snap too. Think the V30 would be a great cut through the mix speaker in this amp.

Anywho thanks for say'n about how the 70/80 did and look forward to what you find on some others.

 

[Leonard Neemoil]

Yah and I usually keep volume right around noon on mine. Maybe others are finding it raspy at lower volumes. I do like the amp more when enough power section is introduced. Playing live can really limit that setting though for sure.

I jammed on the V30 and Electrovoice again. Think I prefer the V30 for the mids and the Electrovoice for the bottom end. So I could go either or otherwise with them. Backing off on guitar volume/tone was great for both. Cool in betweens. The V30 had a bit more of the snap and sting of upper kerrang though the Electrovoice has some snap too. Think the V30 would be a great cut through the mix speaker in this amp.

Anywho thanks for say'n about how the 70/80 did and look forward to what you find on some others.

You jammed the amp with a v30 in the open back combo, or was it an extension cab? Thanks.

 

[solarburn]

You jammed the amp with a v30 in the open back combo, or was it an extension cab? Thanks.

Yes. At volume too(noon). The Electrovoice is in a separate 112 that is semi open back although I had it up against a wall to get more forward punch. Actually had both in the same spot to limit rearward bleed.

 

[Leonard Neemoil]

Yes. At volume too(noon). The Electrovoice is in a separate 112 that is semi open back although I had it up against a wall to get more forward punch. Actually had both in the same spot to limit rearward bleed.

Yes what? There are 2 parts to my question. I think I understand your reply, just trying to clarify. Sorry, thanks.

 

[solarburn]

Reason I like so much volume is I enjoy the thump and fullness of notes when I back off guitar volume/tone. Really gets me off.

I can play quieter but I miss the effect of the power section doing it's magic. I'm not trying to get power tube break up. Just a rounder thumpier snappier Marshall response.lol

 

[solarburn]

Yes what? There are 2 parts to my question. I think I understand your reply, just trying to clarify. Sorry, thanks.

Yes V30 in amp combo, Electrovoice in separate cab. I was being quick. Sorry about the confusion.

 

[Leonard Neemoil]

Yes V30 in amp combo, Electrovoice in separate cab. I was being quick. Sorry about the confusion.

No problem at all. Thanks for taking the time. This makes me want to try one of my v30s in the combo even more. I know it probably won't sound the same as the closed back cab it's in now but I don't really like the seventy-80. I just can't do much physically anymore, otherwise I would've just swapped the v30 in long ago. Your testimony is giving me some hope that it won't be for nothing.

Thanks again.

Cheers!

 

[solarburn]

No problem at all. Thanks for taking the time. This makes me want to try one of my v30s in the combo even more. I know it probably won't sound the same as the closed back cab it's in now but I don't really like the seventy-80. I just can't do much physically anymore, otherwise I would've just swapped the v30 in long ago. Your testimony is giving me some hope that it won't be for nothing.

Thanks again.

Cheers!

Yah speaker changes wipe me out. I just changed out 2 V30's for 12H Annis in my Orange 412 and it did a number on me. Then I had placed the Annis on top and found I prefer them on the bottom of the cab. I needed the V30's upper kerang on top for the mix to suit me. I flipped the cab over to get it and I was right. However i have an upside down Orange logo now. Soon I'll do the actual moving of the speakers.

Actually been changing speakers over the last 2 months in a few different cabs. It's a work out. Unpleasant really.

I prefer the clarity and upper mids of the V30 over the 70/80 for sure. Sounds great clean too.

 

[Micky]

I know I am just beating a dead horse but 533 pages? Well time for a refresher I guess.

You think it is bad reading that many pages? Try writing it.

 

[solarburn]

You think it is bad reading that many pages? Try writing it.

All these years later I still tap in to it for info. Fucking DSL40 Encyclopedia Britannica with expanding volumes.