Cheap/Sucky Amps (Made Good)

[LLL]

Have an amp that either sucked or was cheap, but made it good without breaking the bank?



My Marshall JTM45RI (had for 12 years)... bought it used for ~$600. It was bone stock and it sucked.

(yes, it sucked and it sucked hard)

Added PTP board, lower filtering, NOS tubes (except power and rectifier), MM OT.

Modded it a few times (currently doing mostly a Superlead plexi circuit) and now it's where I want it.

Total cost: ~$1000

 

[jimijames]

Re: Cheap/Sucky Amps (Made Good)

So essentially you bought the shell? A board/tubes/transformer is basically a New amplifier...

Says the guy who modded an epi valve Jr. To Hell and back before replacing everything with a 18w 1974x lite iib pcb. Like the 18w quite a lot now actually.

Total cost: like $500 all said and done

I would like to try a jtm45 though for sure.

 

[LLL]

Re: Cheap/Sucky Amps (Made Good)

So essentially you bought the shell? A board/tubes/transformer is basically a New amplifier...

No, it was a complete, 100% stock Marshall JTM45 reissue amp head.

(bought it off a guy on Plexi Palace forum back in early 2ks when it was cool).

Kept the PT, choke, chassis, etc... But ya it was major "surgery". LOL

Says the guy who modded an epi valve Jr. To Hell and back before replacing everything with a 18w 1974x lite iib pcb. Like the 18w quite a lot now actually.

Total cost: like $500 all said and done

I would like to try a jtm45 though for sure.

Nice. Those 1974s have a sweet circuit and phenomenal tone. How was it soldering on the PCB?

 

[Surgeon]

Re: Cheap/Sucky Amps (Made Good)

I get why people would do that but I would never...
If a factory-made amp didn't sound like what I need from it I'd sell it and buy something else that would fit me better.
If I'm going through that much trouble/surgery, I'll start from scratch and build somethin the way I want it...

 

[80's_Metal]

Re: Cheap/Sucky Amps (Made Good)

All of my amps sound a bazillion times better with this small addition....

:werd:

 

[jimijames]

Re: Cheap/Sucky Amps (Made Good)

No, it was a complete, 100% stock Marshall JTM45 reissue amp head.

(bought it off a guy on Plexi Palace forum back in early 2ks when it was cool).

Kept the PT, choke, chassis, etc... But ya it was major "surgery". LOL



Nice. Those 1974s have a sweet circuit and phenomenal tone. How was it soldering on the PCB?

Yeah sorry that comment was a little ambiguous - I was saying you replaced everything besides the shell basically.

The pcb was really easy - there's a 80+ page build document that comes with it (it was the baby will board over at guitaramplifierpcbs.com)

I put a 5751 in v1 and a 12ay7 in v2 and now it has this really rich clean tone that I love. It has a solid state rectifier so the response is stiffer than with a tube rectifier but honestly in terms of sound it's not terribly noticeable.

I had to replace my pants the first time I played my pg-equipped les Paul through it dimed. Speakers are a v30 and a mojotone 70s greenback clone.

The build doc called for a Chinese OT which wasn't terrible all things considered but it sounds way better with the classictone OT I put in there.

But yeah, I'd still love to play a jtm45 like yours some day.

 

[Gearjoneser]

Re: Cheap/Sucky Amps (Made Good)

I remember being intrigued by the Marshall Class 5 heads, but played one and realized it wasn't as good as it could be.

Then I met a guy who said he gutted one and built it into a 5 watt handwired creation. That sounds like something that would be good, since the 2061 is a $2000 amp and sounds much better.

 

[Securb]

Re: Cheap/Sucky Amps (Made Good)

Reminds my of the muscle car era when every kid wanted to turn his Camaro into a Z28. With the cost of the aftermarket parts the person could have bought a Z28 straight out. At the end of the day they still had a Camaro .

 

[LLL]

Re: Cheap/Sucky Amps (Made Good)

Yeah sorry that comment was a little ambiguous - I was saying you replaced everything besides the shell basically.

The pcb was really easy - there's a 80+ page build document that comes with it (it was the baby will board over at guitaramplifierpcbs.com)

I put a 5751 in v1 and a 12ay7 in v2 and now it has this really rich clean tone that I love. It has a solid state rectifier so the response is stiffer than with a tube rectifier but honestly in terms of sound it's not terribly noticeable.

I had to replace my pants the first time I played my pg-equipped les Paul through it dimed. Speakers are a v30 and a mojotone 70s greenback clone.

The build doc called for a Chinese OT which wasn't terrible all things considered but it sounds way better with the classictone OT I put in there.

But yeah, I'd still love to play a jtm45 like yours some day.

What made you decide to go with lower gain 12AX's (5751, 12ay7)?

Yeah it's funny how the OT can make such a huge difference on the tone.

 

[LLL]

Re: Cheap/Sucky Amps (Made Good)

I remember being intrigued by the Marshall Class 5 heads, but played one and realized it wasn't as good as it could be.

Then I met a guy who said he gutted one and built it into a 5 watt handwired creation. That sounds like something that would be good, since the 2061 is a $2000 amp and sounds much better.

Those 20W 2061s are way overpriced.

 

[jimijames]

Re: Cheap/Sucky Amps (Made Good)

What made you decide to go with lower gain 12AX's (5751, 12ay7)?

Yeah it's funny how the OT can make such a huge difference on the tone.

Well about 3-4 years ago I got some NOS JAN Phillips 5751 tubes for a good price - I used one in the epi valve Jr. Before I built the 1974x and it was and still is my favorite preamp tube. I experimented with a 12at7 and of course with 12ax7s as well and I kept coming back to the 5751.

I went with a 12ay7 in v2 because to my ears it didn't have as noticeable an impact on sound as v1 and those NOS 5751s are expensive little suckers nowadays. Also I liked the feel of the 12ay7 over the at7 because it has a little more give and my particular build has solid state rectification so it's a little "stiff" when you play it, so to speak.

Another benefit of the lower gain tubes, for me at least, is that the amp doesn't break up as early and I absolutely love the clean sound of the 1974x as I've set it up, believe it or not. I run a DIY echoplex boost with buffer (it's the madbean fatpants If you're curious) and with the extra input I find I can go from very beautiful and detailed cleans to thick raucous crunch sounds just on the bridge pickup of my Tele and a volume knob.

I'm also finishing a ton of DIY pedals in the next month including a high voltage rat clone and a jfet treble booster so it should be fun to hear all of them through the 1974x.

 

[LLL]

Re: Cheap/Sucky Amps (Made Good)

Well about 3-4 years ago I got some NOS JAN Phillips 5751 tubes for a good price - I used one in the epi valve Jr. Before I built the 1974x and it was and still is my favorite preamp tube. I experimented with a 12at7 and of course with 12ax7s as well and I kept coming back to the 5751.

I went with a 12ay7 in v2 because to my ears it didn't have as noticeable an impact on sound as v1 and those NOS 5751s are expensive little suckers nowadays. Also I liked the feel of the 12ay7 over the at7 because it has a little more give and my particular build has solid state rectification so it's a little "stiff" when you play it, so to speak.

Another benefit of the lower gain tubes, for me at least, is that the amp doesn't break up as early and I absolutely love the clean sound of the 1974x as I've set it up, believe it or not. I run a DIY echoplex boost with buffer (it's the madbean fatpants If you're curious) and with the extra input I find I can go from very beautiful and detailed cleans to thick raucous crunch sounds just on the bridge pickup of my Tele and a volume knob.

I'm also finishing a ton of DIY pedals in the next month including a high voltage rat clone and a jfet treble booster so it should be fun to hear all of them through the 1974x.

I assume you built the madbean fatpants (it's a DIY IIRC)? Did you use an original TIS58 chip (found in the original Echoplexes) or something else?

 

[jimijames]

Re: Cheap/Sucky Amps (Made Good)

I assume you built the madbean fatpants (it's a DIY IIRC)? Did you use an original TIS58 chip (found in the original Echoplexes) or something else?

I copied the fatpants layout on perfboard because they haven't had the pcbs in stock in over a year - I built a charge pump daughter board with a lt1054 to run the circuit at 24v instead of 18v, and I did a crude treble bypass (100k/100pf in series IIRC) on the level potentiometer because for me on some circuits master level knobs roll off too much treble. For jfet boosts I definitely prefer controlling the output with a potentiometer connected to the source vs. bleeding off signal using a master level potentiometer.

However, I used an mpf102 instead of a TIS58 - the mpf is supposed to be as close to the TIS as you can get without paying NOS prices so I went with it to save money. It sounds great but of course the real deal would sound better I'm sure.

 

[LLL]

Re: Cheap/Sucky Amps (Made Good)

I copied the fatpants layout on perfboard because they haven't had the pcbs in stock in over a year - I built a charge pump daughter board with a lt1054 to run the circuit at 24v instead of 18v, and I did a crude treble bypass (100k/100pf in series IIRC) on the level potentiometer because for me on some circuits master level knobs roll off too much treble. For jfet boosts I definitely prefer controlling the output with a potentiometer connected to the source vs. bleeding off signal using a master level potentiometer.

However, I used an mpf102 instead of a TIS58 - the mpf is supposed to be as close to the TIS as you can get without paying NOS prices so I went with it to save money. It sounds great but of course the real deal would sound better I'm sure.

Cool beans. Yeah, 24v is the sweet spot!

 

[LLL]

Re: Cheap/Sucky Amps (Made Good)

Anyone else?

 

[allbutromeo]

Re: Cheap/Sucky Amps (Made Good)

Not a crap amp, but I got a Fender MIS HRD for under $200 a few years ago. It wasn't working, ended up having to replace V1 socket. After that and changing power tubes it sounds great, but it has now developed an issue where the volume randomly cuts out to almost nothing the randomly comes back. Either way as of right now I have less than $300 in it.