DSL 15H - Modded.

[axepilot]

Another 823 user here. No other mods whatsoever, just the 823 in V1 and a mix of AX7s that I liked the sound of. Still sorting through the right speakers to go with in my 2x12 but that's more on the eq front. For gain amount and texture...its the ecc823 in V1 that makes it happen.

 

[Kinkless Tetrode]

still sorting through the right speakers to go with in my 2x12 but that's more on the eq front..

I like the Vintage 30 or the Marshall Vintage with the DSL15. I'm not a V30 hater -although I usually prefer 25 watt Greenbacks -but with some amps the V30 really works and in my opinion the DSL15 is one of them, at least modded.

I didn't like the DSL15 either stock or modded at all with G12T75s.

FWIW, The Eggz mods here or using the 823 were developed using a G12H Greenback.

 

[axepilot]

Sure, but regardless of what speaker was connected, the 823 is merely a gain shifter. It has very little to do with the eq curve. I do wonder, though. Is there anyone else doing an 823 besides JJ/Tesla?

 

[84LesPaul]

Warning! Newbie question. Can I fit a matched pair of Mullard reissue EL34B tubes to my Dsl15h ? Does "matched" mean that they're already "biased" so I can just plug them straight in?

 

[ampmadscientist]

Warning! Newbie question. Can I fit a matched pair of Mullard reissue EL34B tubes to my Dsl15h ? Does "matched" mean that they're already "biased" so I can just plug them straight in?

Isn't that a Class A amp that is cathode biased?

 

[Micky]

Warning! Newbie question. Can I fit a matched pair of Mullard reissue EL34B tubes to my Dsl15h ? Does "matched" mean that they're already "biased" so I can just plug them straight in?

No. The DSL15 is a 6V6 based amp. It was not designed for EL34's.
Any time you change the finals you must rebias whether the tubes are matched or not.

 

[84LesPaul]

Hey thanks Micky! I have a blown 6V6 so I'll hunt for a matched pair then set about finding someone to rebias for me. Next up I'll be looking for the caps mentioned back at the start of this thread, after trialling the new sound of course!

 

[Kinkless Tetrode]

These have bias connection measuring points on the board. Pretty easy to bias. And most really need to have the bias checked and adjusted. Every one I have checked had the bias way off. Mine was running 100%+ plate dissipation and unmatched between the two tubes. Pulled back to 65-70% the amp sounded much better. These run 425 volts on the plates, so modern 6V6s are probably preferred to NOS.

 

[84LesPaul]

These have bias connection measuring points on the board. Pretty easy to bias. And most really need to have the bias checked and adjusted. Every one I have checked had the bias way off. Mine was running 100%+ plate dissipation and unmatched between the two tubes. Pulled back to 65-70% the amp sounded much better. These run 425 volts on the plates, so modern 6V6s are probably preferred to NOS.

Whoa thankyou so much! This is the kind of information I'm looking for. There is NO ONE it seems in a city of 70,000 people nearby who is capable of telling me where I can find the right tubes or knows enough to guide me in finding and fitting the right ones. Thank heavens for you and people like you on this thread. I'm reading as much as I can but not knowledgeable enough yet to not be scared of making mistakes destroying my amp. I know we learn from mistakes but it's a different story when voltage is involved!

 

[KraftyBob]

Here's a quick and crappy video of the modded dsl 15 head. Big ups to Chadjwil,Micky and Heinreich.
Here's what was done:
R82-add 150k resistor(spot is already there ,but unused)
C58-2n2
C34-snip
C75-snip

[ame=[MEDIA=youtube]C9mOtvA7VtE[/MEDIA] DSL 15 H Modded to sound good. - YouTube[/ame]

Dude - you missed a perfectly good opportunity to jump into REO's Riding the Storm Out with the siren in the beginning LOL.

 

[84LesPaul]

These have bias connection measuring points on the board. Pretty easy to bias. And most really need to have the bias checked and adjusted. Every one I have checked had the bias way off. Mine was running 100%+ plate dissipation and unmatched between the two tubes. Pulled back to 65-70% the amp sounded much better. These run 425 volts on the plates, so modern 6V6s are probably preferred to NOS.

UPDATE: Fitted a matched pair of Mesa Boogie 6V6's and no amount of messing with EQ/Volume/Cables/Pentode/Triode gives me the Marshall "growl" or clarity I'm looking for. I want my cleans to sound like Hendrix, my gain like Slash and everything else like Angus! Is that too much to ask?

 

[Kinkless Tetrode]

UPDATE: Fitted a matched pair of Mesa Boogie 6V6's and no amount of messing with EQ/Volume/Cables/Pentode/Triode gives me the Marshall "growl" or clarity I'm looking for. I want my cleans to sound like Hendrix, my gain like Slash and everything else like Angus! Is that too much to ask?

LOL. In that case you need a Silver Jubilee. It will do all three but maybe not at the same time. Or a 6100. Or a JVM410. Or a maybe a modeler. I was listening to some live Hendrix last night, and it was a sound I have gotten from a SJ before, especially the mini with KT66s.

If you don't need those tones shifting on the fly then a SV20 and a well chosen OD pedal might do.

Your talking about three different speakers too. G12Hs for Hendrix. Vintage 30s for Slash. G12Ms for Angus.

 

[solarburn]

LOL. In that case you need a Silver Jubilee. It will do all three but maybe not at the same time. Or a 6100. Or a JVM410. Or a maybe a modeler. I was listening to some live Hendrix last night, and it was a sound I have gotten from a SJ before, especially the mini with KT66s.

If you don't need those tones shifting on the fly then a SV20 and a well chosen OD pedal might do.

Your talking about three different speakers too. G12Hs for Hendrix. Vintage 30s for Slash. G12Ms for Angus.

I'd go G12M's. Yes...I'm biased however my 5153 cab with G12M's can go heavy and hard and classic!

 

[84LesPaul]

LOL. In that case you need a Silver Jubilee. It will do all three but maybe not at the same time. Or a 6100. Or a JVM410. Or a maybe a modeler. I was listening to some live Hendrix last night, and it was a sound I have gotten from a SJ before, especially the mini with KT66s.

If you don't need those tones shifting on the fly then a SV20 and a well chosen OD pedal might do.

Your talking about three different speakers too. G12Hs for Hendrix. Vintage 30s for Slash. G12Ms for Angus.

Yup, and different guitars too! Mine is the one in my picture profile. Realistically I'm never going to achieve the exact sound of my idols but my dsl 15h could sound way better. I'm going to visit a guy who knows his shit and also has a collection of vintage amps for me to compare/educate myself (including a Marshall Pig!). Very much looking forward to playing around with his gear and mine. Also have a buddy with a Silver Jubilee, JCM 800/900 and a few other bits and pieces to muck around with and learn more about Marshalls and what makes some of them sound so damn good. Thanks for your input, very much appreciated. Cheers from NZ.

 

[acosta]

Regarding R82: Does it matter if the resistor is either 1/2 or 1/4 watt? Thanks,

 

[Peter McAteer]

Regarding R82: Does it matter if the resistor is either 1/2 or 1/4 watt? Thanks,

I've read in a few places that it's 1/2 watt you're looking for.

 

[petar93.mar]

Hey guys I wanted to take a little time to thank you for posting all of these great ideas and giving a rat's ass about strangers in the process… I am one of those strangers. I'm happy to share that I've implemented the lead 2 to lead 1 conversion. So great and worthwhile.
Marshall is apparently tricky about protecting its high-end models. They could have made the 2203 channel switching but they didn't. The channel switching amplifier of that era had diodes in the preamp circuit that kind of sabotaged it, apparently to protect the 2203's space in the market.
Well, the DSL 15 is the same kind of thing. They deliberately sabotaged it by putting lead 2 in instead of lead 1. That way the DSL 40 is protected. Somebody in-house must have had some sympathy for us, though, by leaving the space in the circuit board for the resistor to knock it back down from lead 2 to lead 1. So thank you, too, unnamed rogue Marshall employee!
My only variation: Lead 1 is still too bright, so switching between the two channels is not as seamless as it should be shared EQ-wise. So, I clipped the other 470 pF capacitor at the gain pot (the one that does not run series to the big resistor you install) and installed a 120 pF in its place (a standard value cap in a fender tone circuit… I used silver mica). This is more or less perfect to my ears. When I go to the red channel now, a slight amount of both treble and bass are rolled off from the clean, with a nice mid range boost. In other words, I think it's perfect now. Perfect!
After all of this effort, I finally cranked it just lately, and I've got to say it: the clean channel cranked is absolutely incredible. It might be exactly the sound we're all really after. So Johnnyeggz, you might want to gig with your clean channel, actually... After all. Marshalls... when you crank 'em up suddenly they sound right, and all the bass comes out (hence the deep switch). I can't say that I've ever heard an amp other than Marshall that needed so badly to be cranked to sound right.
But this conversion is still very much worthwhile obviously. Just remember to crank your clean channel some day. Really really great. Marshall really made this amp true to classic form, and it is born to crank, just like the classics.
Aborted ideas: 1. I thought of installing the clean crunch channel and making it footswitchable, but that would have changed the volume from clean... And, you can probably accomplish just about the same thing with a boost footpedal. Notably, the worthless tone shift switch happens to have the right number of poles on it to accommodate a crunch switching function. You would just desolder the switch and turn it upside down and glue it and do your wiring from there. Of course a parallel relay for footswitching is possible and adds complexity. 2. I also considered buying the reverb circuit that is installed on the DSL 15c (And installing the knob; the space is there for the pot) but it probably sucks. Besides, 3. an effects loop for better reverbs would be easier and better... And I don't get out of the 8 to 9 o'clock area anyway so a front end reverb doesn't get way out of hand for me. It does get out of hand if you put your gain much higher than that, but I don't (out of hand is still not bad… out of hand as in the reverb sound at the end of Van Halen's eruption). 4. Lastly, a standby switch next to the power switch would be nice. But I'm not sure there's room for a right-looking full size one. Is there a three position rocker switch that could be put in the existing power switch's place?
DSL19.6: I also want to mention that I used an oscilloscope to calculate the actual wattage of this amp and it was somewhere over 19 Watts at 1khz before distortion (with jj 6v6s, and all eq cranked and deep on). I guess they couldn't have marketed it honestly as a 20 W so they went down to 15 because 19 is not a very marketable number (and they didn't want you to realize its almost as loud as the 40, which is combo only...). The deluxe reverb has the same plate voltage as the dsl15, and it has just about the same output power... So they're both lying but Marshall is more innocent than Fender.
Speakers/pickups/etc.: I have the matching stand up 2 x 12 Marshall closed slant cabinet and it's pretty good with greenbacks... Very Hendrixy with a 69 strat. But a standard 2 x 12 semi open back is awfully tough to beat... Equal bottom end, but brighter and louder. Each has its place. My Les Paul has burst bucker pro pick ups. I have my tone knobs at about 2 (for strat too). I use my EQ at straight up at normal volume, but when I crank it, it's nice to have everything all the way up and my tone knobs set at 0. Perfect woman tone. When in triode mode, though, I need to turn the tone knobs up just a little bit because the increased power tube capacitance eats a little bit of the high-end.
Last thing: my DSL 15 must be a very early model. All of the components are numbered differently from the schematic. Everybody else's C 76 and 75 are my C 75 and 74 for example. Most numbers are a lot farther apart (my Lead 1resistor is WAY off...). Maybe this will help somebody out there. Without the PCB pictures I would've been totally screwed... thanks Johnnyeggz for those.
Also, if cranking happens to apparently kill your amp, here's something funny: the two fuses that were in my DSL 15 were of equal value... From the factory. A manufacturing error. The fuses are supposed to be different amperages but I had two of the same low amp fuses. I blew that fuse upon crank up and about had a heart attack, but discovered the problem. I put in the correct fuse and now I can crank all damn night long.
Thank you everyone. Great information and a great transformation. Just awesome. $2000 amp sound.
Oh one more thing – sorry. I noticed that the heater circuit for V1 is converted to DC. Brilliant idea. Makes the amp really quiet. They should advertise these facts on the web! I mean that really is a great idea. They were NOT jacking around when they made this amplifier.
PS- Johnnyeggz's YouTube video series is what originally hooked me. Major props, Johnny. Next time a fire truck goes by, stick your cabinet in your window like an AC unit and give 'em some AC... AC/DC.

Hey Jason, in regards to your statement about the brightness: is it the C76 (in ours)? I know it's been a few years, but heck, I should try

 

[Telefan]

Yeah, that's exactly what happened on my end (@ vivan) as well, nothing, then a few clicks on/off and it simply "woke up". It was kinda like when you first plug two new pieces of HiDef components together via an HDMI cable for the very first time, they have a "handshake" moment, then they work together. Still, after trying C76 snipped I simply didn't care for it, became a bit mushy, had to nearly dime the treble to get back some open clarity.

I think I'm sticking where I'm at. The green channel is great for cleans, it takes pedals really well, and now, thanks to Johnnyeggz and Co. I've got a killer, more traditional "Marshall" crunch on the red channel. All is well! Peace.

I have followed Johnnyeggs from the beginning. His mods on my DSL15 have changed it from a buzzing fizz box to a real DSL with Plexi tones. LOVE the mods.