No wonder my DSL sounds like arse

[JeffB]

And has eaten up two sets of tubes.I could never get this weird harshness out of it, no matter what....

Wonder why??? :thumbsdow

Side one


Side two



I was pretty wary biasing it myself, but I was super cautious, and got them both to read 37.9-38.0 and the amp now sounds AND feels GLORIOUS like a Marshall should. Its like I got a completely new/different amp. Red channel made a significant improvement in bottom end, but I should have done the c19 mod while I was in there.

HALLELUJAH!

 

[d1dsj]

Re: No wonder my DSL sounds like arse

FairPlay to you, I really should learn to bias my own amps too. Glad you found out why it was sounding off.

 

[JeffB]

Re: No wonder my DSL sounds like arse

Im floored at the difference and I wish I would have done it sooner. So I'd say do it. I expected to be actually biased cold, as apparently that is common with Marshall. Marshall employee must have biased my amp on a friday afternoon.

 

[Cipher]

Re: No wonder my DSL sounds like arse

Congrats on the DIY fix! Mine likes the bias @ 37-38 mA as well.

 

[DankStar]

Re: No wonder my DSL sounds like arse

so when you put in the second set to get eaten up, it wasn't biased then?

 

[JeffB]

Re: No wonder my DSL sounds like arse

so when you put in the second set to get eaten up, it wasn't biased then?

They were matched to the original set.

 

[TwilightOdyssey]

Re: No wonder my DSL sounds like arse

Cool beans!

 

[Nostalgic Distortion]

Re: No wonder my DSL sounds like arse

They are relatively easy to bias as far as most amps go no? I think I remember something about 3 prongs & a couple of pots? The middle prong is the ground or negative terminal & the outside ones represent the valves but the adjustment pots are backwards in relationship to the tubes right?

Sorry for all the questions, I'm actually really curious! After reading about the way yours was factory set & a dozen other stories just like it I'm thinking it might be a good idea to check mine just for turds & squirts??? I briefly looked into how to bias them when I bought it & I think I remember saying "I can do that, it looks easy enough" but please correct me if I'm wrong. I don't want to get in over my head but I know some basic stuff and I like to think I have a little common sense when it comes to the inside of one, but an amp tech I am not!!!

 

[JeffB]

Re: No wonder my DSL sounds like arse

It was easy enough. One tube dialed in easy peasy. The other really took some miniscule finessing. Overall, 10min maybe. You are correct on the bias points and trim pots.

Video below.

I picked up the meter and hook probe set (sold separately) on amazon for $26 toal.

 

[GilmourD]

Re: No wonder my DSL sounds like arse

Did it look like the red light district behind your amp? Jeez.

 

[Gearjoneser]

Re: No wonder my DSL sounds like arse

It seems funny nowadays that people used to say "this amp is a good one" when tubes and bias were probably the only differences.

Every tube amp owner should own a volt/amp meter and a bias tool. I'm glad that many new amps have external bias points, or are self biasing.

Glad you sorted that out. 38mA is a good number for EL-34's, and 32mA is about right for 6L6's. I think my 6550's come in around 42mA.

 

[Gearjoneser]

Re: No wonder my DSL sounds like arse

Also, I see the metal handled mini screwdriver and towel. Good thinking on the towel but a plastic handled one is best. Bare hands on a metal handled screwdriver can kill you. Never put your other hand on the chassis at the same time either. If you get shocked with that much amperage, you can literally get locked to the amp till you die, unless you're lucky enough to drop the chassis or fall away.

I've had something like that happen to me twice.

 

[JeffB]

Re: No wonder my DSL sounds like arse

Also, I see the metal handled mini screwdriver and towel. Good thinking on the towel but a plastic handled one is best. Bare hands on a metal handled screwdriver can kill you. Never put your other hand on the chassis at the same time either. If you get shocked with that much amperage, you can literally get locked to the amp till you die, unless you're lucky enough to drop the chassis or fall away.

I've had something like that happen to me twice.

Thats what I thought about the screwdriver too, Joe...but I saw the guy in the video using the same type, so I kind of brushed it off. Next time I will use a different one.

I did have my other hand in my pocket while I did it.

 

[JeffB]

Re: No wonder my DSL sounds like arse

Did it look like the red light district behind your amp? Jeez.

They never looked like they were red-plating. Not nearly as bright as the el84s in my 3 other class A amps do/did get. Fricking Marshall.

 

[Lake Placid Blues]

Re: No wonder my DSL sounds like arse

I have seen several Vietnam DSLs that had hot (as much as 95% dissipation) and mismatched bias. This should be done with everyone of them. You don't know what it might be set at?

 

[Myaccount876]

Re: No wonder my DSL sounds like arse

Also, I see the metal handled mini screwdriver and towel. Good thinking on the towel but a plastic handled one is best. Bare hands on a metal handled screwdriver can kill you. Never put your other hand on the chassis at the same time either. If you get shocked with that much amperage, you can literally get locked to the amp till you die, unless you're lucky enough to drop the chassis or fall away.

I've had something like that happen to me twice.

I also use rubber gloves. The thicker, the better.

 

[Leon Of Late]

Re: No wonder my DSL sounds like arse

Also, I see the metal handled mini screwdriver and towel. Good thinking on the towel but a plastic handled one is best. Bare hands on a metal handled screwdriver can kill you. Never put your other hand on the chassis at the same time either. If you get shocked with that much amperage, you can literally get locked to the amp till you die, unless you're lucky enough to drop the chassis or fall away.

I've had something like that happen to me twice.

Thats what I thought about the screwdriver too, Joe...but I saw the guy in the video using the same type, so I kind of brushed it off. Next time I will use a different one.

I did have my other hand in my pocket while I did it.

I also use rubber gloves. The thicker, the better.

These are all reasons why I take my amp to a pro when it needs to be biased. I'd rather pay $50 instead of being dead. I'm not completely mechanically inept, but electricity scares the bejesus out of me.

 

[GilmourD]

Re: No wonder my DSL sounds like arse

I also use rubber gloves. The thicker, the better.

And keep one hand in your back pocket while wearing rubber soled shoes. You don't want to create a path through your heart for the electricity to flow. THAT is what kills ya. Localizing the shock to just your hand will leave your hand feeling weird for a couple days (120VAC across my right hand) but you'll live.

 

[PFDarkside]

Re: No wonder my DSL sounds like arse

I wonder how all those speakers would sound now...

 

[JeffB]

Re: No wonder my DSL sounds like arse

I wonder how all those speakers would sound now...

No doubt better. Everything sounds better now. I run my pedals straight in and they all sound so much better. Even the crappy onboard reverb sounds alot better now. No kidding. Much less digital.Useable now l, but still sounds meh.

The creambacks I sold didnt give up the goods for my tastes unless the amp was through the roof loud..I am not regretting any of those buys/sales. Great speakers, but not where I needed to be once I got em and tried them. The green beret Id had for a couple years and A) didnt like it nearly as much as the celestions and B) wrong ohms for what I now use (same with the mojotone h30)

I still have my h30 70th, EVH g12m20s (x2), V30 is in the combo cab, and I just picked up a standard g12m greenback (chinese) which is in the 2x12 cab with the 70th, subbing in for an EVH for a trial run. The chinese m25 is a couple db louder than the EVH, which kind of gets lost in the cab with 70th. The m25 are also a little more aggressive and they have a bit more headroom. ..Really they sound more like Blackbacks, and the EVH have more of that late 60s/very early 70s thing going on (sweeter, warmer, more compressed when pushed).