1W JTM build

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Bieworm
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Re: 1W JTM build

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Re: 1W JTM build

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OMG!!! I feel so stupid!!! Moron!!!!
Listen: the amp has a 0.1W attenuator switch... I was trying to fix the sound the entire time on that stupid 0.1W position!!!
Listen to this dudes.. this is the 1W position:
https://www.dropbox.com/s/jqt0i2dgi7vtq ... 1.m4a?dl=0
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Re: 1W JTM build

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Yay!! hurray hurray

But it's too good to sell now!

Jack
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Re: 1W JTM build

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TriodeLuvr wrote:
Wed 06/23/21 2:14 pm
Yay!! hurray hurray

But it's too good to sell now!

Jack
Naah.. it's good..awesome in fact, but still ain't no Tremolo TMB Reverb!!!
God, I feel so stupid.. I was checking how terrible the 0.1W switch would sound, because that kind of attenuating is never good sounding.. and katchinggg.. loud!!!
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Re: 1W JTM build

Post by JMPGuitars »

Much better!

There's still a touch of articulation missing in a couple guitar positions (0:51-1:06, 2:58-3:11 mostly). That could be the amp, the speaker, or the pickups. Whatever it is, you could try adjusting the tone knobs (just turn them, don't replace anything) to get a little more mids, maybe a tiny bit less highs.

Overall though, very nice.

Thanks,
Josh
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Re: 1W JTM build

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JMPGuitars wrote:
Thu 06/24/21 6:41 am
Much better!

There's still a touch of articulation missing in a couple guitar positions (0:51-1:06, 2:58-3:11 mostly). That could be the amp, the speaker, or the pickups. Whatever it is, you could try adjusting the tone knobs (just turn them, don't replace anything) to get a little more mids, maybe a tiny bit less highs.

Overall though, very nice.

Thanks,
Josh
You're right. As for tone settings they are : Bass 12 O' clock / mid 3'O clock / treble 12 O' clock
there's already a 50k pot for the mids, with a .01uf cap. Maybe I'd better change the 500pf treble cap back to 250pf? Change the slope resistor to lower value? There's 56k in there right now.
I don't think the speaker is the problem.. it's a V30, so the least that one lacks is mids :wink:
I'm going to put the GE 12AU7 back in.. it seemed to sound better than the Mullard. The cathode voltage went up 0.15V with the mullard, compared to the GE.
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Re: 1W JTM build

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Bieworm wrote:
Thu 06/24/21 7:02 am
You're right. As for tone settings they are : Bass 12 O' clock / mid 3'O clock / treble 12 O' clock
there's already a 50k pot for the mids, with a .01uf cap. Maybe I'd better change the 500pf treble cap back to 250pf? Change the slope resistor to lower value? There's 56k in there right now.
I don't think the speaker is the problem.. it's a V30, so the least that one lacks is mids :wink:
I'm going to put the GE 12AU7 back in.. it seemed to sound better than the Mullard. The cathode voltage went up 0.15V with the mullard, compared to the GE.
Maybe, or try a different speaker. There are certainly points that feel like there's too much highs, and that's common with the V30. Try one of your sacred speakers and see what the difference is before changing anything else.

Thanks,
Josh
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Re: 1W JTM build

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Josh.. the moments on the recording you refer to are the ones where I play the tele neck pickup.. those are muddier by nature.
Does that explain some?
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Re: 1W JTM build

Post by JMPGuitars »

Bieworm wrote:
Thu 06/24/21 10:14 am
Josh.. the moments on the recording you refer to are the ones where I play the tele neck pickup.. those are muddier by nature.
Does that explain some?
Yes, I'm aware you switched the pickup. The question is- does that pickup normally sound muddy, or do you get better articulation in that position on other amps?
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Re: 1W JTM build

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JMPGuitars wrote:
Thu 06/24/21 11:35 am
Bieworm wrote:
Thu 06/24/21 10:14 am
Josh.. the moments on the recording you refer to are the ones where I play the tele neck pickup.. those are muddier by nature.
Does that explain some?
Yes, I'm aware you switched the pickup. The question is- does that pickup normally sound muddy, or do you get better articulation in that position on other amps?
I'll do a recording with my jazzmaster or the red tele I built. They are clearer in the neck pos.
I did the previous recording with the White tele. That one is blackguard voiced , muddy neck.
Just had rehearshal with the band for the first time since september.. 36W tremolo tmb reverb.. oh man this was awesome!!!
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Re: 1W JTM build

Post by edsonmarquezani »

JMPGuitars wrote:
Mon 06/07/21 1:35 pm
Speaker characteristics will play a big part in this too though. And keep in mind, some of those Marshall tone stacks can be a bit ice-picky. Though I would love to hear an A/B comparison in the same circuit of both options. ;)
Hey guys, I've been messing around with this project for a while, it was actually the very first handmade amp I built. Matec released a very well-documented project which he called HTM-1 in the Brazilian Handmades forum http://www.handmades.com.br/ a few years ago and it was my starting point.

I've always complained about the excessive low end, and ended up selling the amp. After reading this thread I got interested on trying this "cathode follower" option with a LND150 mosfet (since I had it here), as found in the JCM1 variant.

I did it, and it works perfectly, however it doesn't play an important role in the tone frequency wise, in my opinion, but it does add quite some boost to it (as expected). What I really found useful for taming the low end was changing the V2A bias to something colder (like a cold clipper but not so cold - 2k7, 4k7). It lowers the overall gain, but the cathode follower boost compensates at least part of it, and you get more a tight tone. But I always run the amp with the bass control very low, anyway. I guess it's just how the "JTM45-ish" tone is, after all.

I could record something, eventually, if you are interested.
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