Tubes For Lower Gain Sound?

[astrozombie]

Hi guys,

as you may or may not know my amplifier of choice at the moment is a Marshall DSL401 combo. This amplifier is very good since it has been upgraded with a vintage 30 speaker, it helped the sound a lot.

I'm looking for any other tubes i can use in it that will lower the gain stage so that I can crank the gain control higher.

right now after "5" on the gain knob, there is way too much distortion to be useable. I figured that some lower gain tubes might be able to clean up the amp so that the control has more usable range.

the amp has 4 EL84 tubes and 4 12ax7 tubes.

any suggestions? My guitar has vintage style humbuckers.

 

[JB_From_Hell]

Re: Tubes For Lower Gain Sound?

12AT7 tubes will have less gain than 12AX7s. I have zero experience with Marshalls, so research before swapping, but I think that would help.

 

[Powerstrokedr]

Re: Tubes For Lower Gain Sound?

12au7 in pi will drop gain low, 5751 in Pi or v1 works well too. The 12au7 in pi will let you crank the amp enough to get the power tubes to distort.

 

[JeffB]

Re: Tubes For Lower Gain Sound?

Find some old JAN 5751s. They are not too expensive and sound great.

 

[Demanic]

Re: Tubes For Lower Gain Sound?

JJ's makes a medium gain 12ax7.

Sent from my MotoE2(4G-LTE) using Tapatalk

 

[guitfiddle]

Re: Tubes For Lower Gain Sound?

You could also try a 12AY7 in V2.

 

[Shooter.556]

Re: Tubes For Lower Gain Sound?

Mullard reissues sound nice and give a good low gain vintage tone.

 

[GuitarDoc]

Re: Tubes For Lower Gain Sound?

Depending on how much you want to reduce your gain, here is a chart showing general gain factors, using 12AX7 as equal to 100%:
12AX7 = 100
5751 = 70
12AT7 = 60
12AY7 = 45
12AV7 = 41
12AU7 = 19

12AT7 makes a great PI tube. Also 5751.

 

[Myaccount876]

Re: Tubes For Lower Gain Sound?

Not all of those tubes are a retrofit swap for each other. They all have vastly different plate voltages and biases.

5751 is the "proper" lower gain replacement for a 12AX7, as it was designed to have the same plate resistance of a 12AX7 with lower gain. 12AX7 and 12AT7 are the only ones I see as "close enough" where they can usually be swapped for each other, but I still wouldn't say it is ideal. There are also 12AX7s that sound cleaner - I love the Sovtek 12AX7LPS for this. Works great in the PI and in the gain stages if you want a cleaner sound.

 

[TwilightOdyssey]

Re: Tubes For Lower Gain Sound?

ECC 832 is my valve of choice for doing just that, provided your amp uses both sides of V1...

 

[FuseG4]

Re: Tubes For Lower Gain Sound?

you could try the el84M power tubes?
Some say they sound "cleaner" a little.

 

[IM4Tone]

Re: Tubes For Lower Gain Sound?

Read and listen to THIS.
To tame gain, I plug one of these (usually a 5751 or sometimes a 12AT7) into V1. Works well for me. I'm not nearly as concerned about brand as I am type.

 

[Myaccount876]

Re: Tubes For Lower Gain Sound?

you could try the el84M power tubes?
Some say they sound "cleaner" a little.

If you're refferring to the Sovtek EL84M's, I'd avoid those at all cost. In fact, usually anything advertised as "Military grade tubes" with an up-charge is a scam. "Military-grade" really means "lowest common denominator", not "high performance" or "long lasting" - I once ordered a pair of matched Sovtek EL84M's, and they became unusable (sound both crackling and cutting in/out - problem went away as soon as replaced with working tubes) after two months of light use. They weren't damaged in shipping, and they had no physical wear. "Military-grade" with tubes mean that they would just test barely read as "ok" on a tube tester, as in they'll power up the circuit for that moment; doesn't mean they'll work as desired for audio applications. I'm never wasting my money on that again - just buying standard versions of brands with decent QC is good enough (many different brands' tubes come from the same source - the different brands just have different QC standards/price points).

 

[misterwhizzy]

Re: Tubes For Lower Gain Sound?

If the problem is that the amp becomes unusable with the gain above five, I think the answer is to keep the gain below five.

 

[JOLLY]

Re: Tubes For Lower Gain Sound?

If the problem is that the amp becomes unusable with the gain above five, I think the answer is to keep the gain below five.

I was beginning to think that I was the only one thinking that.

 

[ItsaBass]

Re: Tubes For Lower Gain Sound?

If the problem is that the amp becomes unusable with the gain above five, I think the answer is to keep the gain below five.

Exactly.

If you want headroom, you have the wrong amp. You want one of the 100 watters, if a Marshall at all (headroom is not exactly a pressing design goal of Marshall amps in general).

What I'd do is run the gain where it sounds best, and simply mic yourself and/or use extension cabs if it isn't loud enough for you.

 

[astrozombie]

Re: Tubes For Lower Gain Sound?

Exactly.

If you want headroom, you have the wrong amp. You want one of the 100 watters, if a Marshall at all (headroom is not exactly a pressing design goal of Marshall amps in general).

What I'd do is run the gain where it sounds best, and simply mic yourself and/or use extension cabs if it isn't loud enough for you.

it's about taming the RED channel.

The clean and overdrive 1 channels are spectacular with my Les Paul.

 

[Funkfingers]

Re: Tubes For Lower Gain Sound?

So, to summarise, you are displeased by where the pointer on the control knob happens to be when you have your desired pre-amp gain setting dialled in?

Jeeziz Aitch Christ.

Bring on the Tommy Lee Jones implied face palm meme.

 

[Funkfingers]

Re: Tubes For Lower Gain Sound?

after "5" on the gain knob, there is way too much distortion to be useable.

Examine the DSL401 circuit diagram. How much of the red channel gain is pure, cascaded valve drive and how much is derived via IC chips?

Also, is the Gain pot logarithmic (audio) or linear taper?

How clean can you get the red channel to sound if you wind the guitar volume pot(s) down from 10 to approximately 3 or 2?

 

[JeffB]

Re: Tubes For Lower Gain Sound?

This is an issue for alot of people with DSLs whether original JCM or tbe new MIV versions...red channel is just stupid amounts of gain beyond 11 oclock, and on some like thre DSL15, red channel is nearly useless. I hate the red channel on my 40. It sounds great on demos but in the room is a nasally thin hot mess...red 2 is beefier , but still.no wbere near the roar/balls of green channel. Alot of people clip or sub a different value cap @ c19 on the 40, and they say it makes a world of difference, others say it muds red up. Im sure there are mods out there for the 401.

At any rate, red channel on a dsl seems to be a love it/hate it thing. IMO /IMEgreen crunch with a goose is a far better solution if you need more gain.