Disappointed with 1987x, JTM45 RI (component quality)

[Trem man]

Marshall is a big brand like Fender. Once Marshall could no longer get Drake trannys things changed. The later "Dagnalls" weren't the same as the old ones either. And PCB construction, yuk. For what they're charging they should offer higher quality in both the 1987X and the JTM45 RI's. For the same money you can buy handwired Friedman, Suhr, etc. Or you can pay thousands more for old vintage Marshalls but they might not be the best daily drivers for gigs. Just my 2 cents, ymmv. I love my older Marshalls, even the pcb stuff with Drakes.

 

[knulp]

Aaaand there's a pretty big discrepancy. Numbers are pretty similar on the power tubes, maybe about 15 VDC hotter on the clone, but that increases to 72 VCD difference at V1A's power rail. Feeling pretty silly for having overlooked this, but I guess that's why I came here. Appreciate the advice!

1987x:
V1a: 261 rail, 150 plate, .93 cathode
V1b: 261 rail, 198 plate, 1.7 cathode

V2a: 278 rail, 155.5 plate, 1.02 cathode
V2b: 278 rail, 155.5 grid, 157 cathode

V3a: 325 rail, 210 plate, 23.5 grid, 38.2 cathode
V3b: 325 rail, 208 plate, 24.5 grid, 38.2 cathode

V4 & 5: 468 plate, 460 screen, biased to 65%

Clone:
No v1a ("replicated" with a 220k resistor from rail to gnd)
V1b: 333 rail, 253 plate, 2.17 cathode

V2a: 357 rail, 198 plate, 1.32 cathode
V2b: 357 rail, 198 grid, 200 cathode

V3a: 357 rail, 239.5 plate, 24.5 grid, 39 cathode
V3b: 357 rail, 225 plate, 25.5 grid, 39 cathode

V4 & 5: 482 plate, 480 screen, biased to 65%


Still proceeding with the board swap, if for no other reason at this point than I still much prefer how my clone sounds / feels, and replacing the 1987's PCB will make it SO much easier to work on.

I don’t think the differences you are hearing are due to lower quality components in the 1987x.
You are omitting a stage (v1!!) in the clone and replacing with a 220k to ground..
And different voltages and who knows what else..
We are talking about two different amps and your preference between the two.
Honestly I don’t think the 1987x needs a new board..tagboard vs pcb means nothing in terms of tone ..if any I would just put Mallory caps (and not expensive sozo or the likes..)

But what I suspect is that you are simply used to the “clone” and you like it.
No reason to clone that “clone”..
And two amps will never sound the same

I would try to get used to the 1987x tone and to the differences between the two..it’s not a no name generic amp..it’s a legendary masterpiece ..

 

[TheMagicEight]

I don’t think the differences you are hearing are due to lower quality components in the 1987x.
You are omitting a stage (v1!!) in the clone and replacing with a 220k to ground..
And different voltages and who knows what else..
We are talking about two different amps and your preference between the two.
Honestly I don’t think the 1987x needs a new board..tagboard vs pcb means nothing in terms of tone ..if any I would just put Mallory caps (and not expensive sozo or the likes..)

I get what you're saying, but do you think V1a is that important? I'm only using the bright channel on either amp, so I wouldn't think this matters. The 220k was just meant to simulate there being another triode from the power rail, though I doubt it makes a material difference.

Regarding the board swap, at this point if I'm going to swap the caps, I might as well swap the board. It's so annoying to work on in its current form. I've also read about parallel traces acting as low-value capacitors. I can't quantify that in this board, but why not remove the possibility and eliminate the psychological factor?

Regarding Sozo vs Mallory, I've had good luck with both in the past. I've got Sozo in the clone, and the extra cost is what, $30? I spent $2200 on the amp...

But what I suspect is that you are simply used to the “clone” and you like it.
No reason to clone that “clone”..
And two amps will never sound the same

I would try to get used to the 1987x tone and to the differences between the two..it’s not a no name generic amp..it’s a legendary masterpiece ..

I've really tried with the 1987x in its original form. Spent a few months with it before I started tinkering. I think the core is that I prefer the mid to late 60s circuits -- lower filtering, lower bright cap values, Bassman tone stack, higher NFB, etc. Although I do like the 2.7k cathode on V1b.

If it was a 70s amp I'd be much more inclined to keep things original, but a reissue is an interpretation of a legendary masterpiece. I love the way the clone sounds and have always wanted that tone in a good package. The other aspect is just a desire to understand cause and effect.

I've since upped the voltages in the 1987x and this gets much closer to the feel that I'm looking for, but still a ways off on overall brightness. I've got a 3H choke in the clone, and the 1987x has a 5H choke. Wondering how much that matters...

 

[SlyStrat]

Took the bright cap out of mine.

 

[TheMagicEight]

Here's the schematic I drew up of the clone if anyone's interested

 

[knulp]

The. H

I get what you're saying, but do you think V1a is that important? I'm only using the bright channel on either amp, so I wouldn't think this matters. The 220k was just meant to simulate there being another triode from the power rail, though I doubt it makes a material difference.

Regarding the board swap, at this point if I'm going to swap the caps, I might as well swap the board. It's so annoying to work on in its current form. I've also read about parallel traces acting as low-value capacitors. I can't quantify that in this board, but why not remove the possibility and eliminate the psychological factor?

Regarding Sozo vs Mallory, I've had good luck with both in the past. I've got Sozo in the clone, and the extra cost is what, $30? I spent $2200 on the amp...


I've really tried with the 1987x in its original form. Spent a few months with it before I started tinkering. I think the core is that I prefer the mid to late 60s circuits -- lower filtering, lower bright cap values, Bassman tone stack, higher NFB, etc. Although I do like the 2.7k cathode on V1b.

If it was a 70s amp I'd be much more inclined to keep things original, but a reissue is an interpretation of a legendary masterpiece. I love the way the clone sounds and have always wanted that tone in a good package. The other aspect is just a desire to understand cause and effect.

I've since upped the voltages in the 1987x and this gets much closer to the feel that I'm looking for, but still a ways off on overall brightness. I've got a 3H choke in the clone, and the 1987x has a 5H choke. Wondering how much that matters...

The choke makes for a very tangible difference in feel.

Have you tried swapping tubes from the clone to the Marshall?tubes do make a difference

I doubt that the1987x pcb is so badly designed to worry about parallel traces and capacitive effects..very very unlikely,let’s say impossible.
It may not be to most expensive amp on the planet but come on,Marshall have gifted designers since I was not born..

You are right about servicing a pcb and they do not make a superbass reissue though,but that’s the only reason I see to change the board

Still , it’s easy to convert that pcb to the specs you are talking about

Don’t get stuck in the boutique nonsense,expecially since in this case it’s a matter of amp design and not fine tuning

I have a few hand wired amps and pcb amps and I know that Mallory caps are more than enough for great tone..I have enough experience with hand wired to say that a 1987x pcb deserve to be in an amp..

 

[knulp]

If I have grasped the situation ..
You may need to put the clone in a nice head shell!!

 

[TheMagicEight]

If I have grasped the situation ..
You may need to put the clone in a nice head shell!!

Haha well that'd be ideal! Truthfully, I don't want to touch it until I 100% understand why it sounds the way it does / why it sounds so different from the 1987x.

 

[knulp]

The input stage with the two channels is important in a plexi and you don’t have that

But I don’t believe that to be the reason
You have already found that upping voltages brings you closer
But you still have different transformers and probably different tubes.
However at this point it should be easy to match the brightness via different caps

But making or buying a nice Marshall headshell for an amp you love is a happy road!!

 

[TheMagicEight]

The choke makes for a very tangible difference in feel.

Just received a 3H C1999 in the mail, super curious to try that out. I'm wondering how much impact it'll have on the tone, or if it's more of a feel thing.

Have you tried swapping tubes from the clone to the Marshall?tubes do make a difference

Yup, one of the first things I did. Very little difference.

I doubt that the1987x pcb is so badly designed to worry about parallel traces and capacitive effects..very very unlikely,let’s say impossible.
It may not be to most expensive amp on the planet but come on,Marshall have gifted designers since I was not born..

I think you're right. The only exception is if they did something deliberate (Mesa claims they did something like that in their Rectifier board design, but those things are kind of a mess anyway). I can't imaging the board is the problem, but again, eliminate variables and make it way easier to work on.

Still , it’s easy to convert that pcb to the specs you are talking about

I think it'd involve lifting the board to access the underside, no? Which at that point means removing the leads from half the board, which at that point I'd rather just swap it out, lest I have to do it twice.

Don’t get stuck in the boutique nonsense,expecially since in this case it’s a matter of amp design and not fine tuning

I have a few hand wired amps and pcb amps and I know that Mallory caps are more than enough for great tone..I have enough experience with hand wired to say that a 1987x pcb deserve to be in an amp..

Not really stuck on it so much as eliminating variables between the two. It'd be a fun experiment to compare the caps: Mallory vs Sozo vs the GDs in there now. Much easier to do when the board is swapped.

 

[2L man]

Aaaand there's a pretty big discrepancy. Numbers are pretty similar on the power tubes, maybe about 15 VDC hotter on the clone, but that increases to 72 VCD difference at V1A's power rail. Feeling pretty silly for having overlooked this, but I guess that's why I came here. Appreciate the advice!

1987x:
V1a: 261 rail, 150 plate, .93 cathode
V1b: 261 rail, 198 plate, 1.7 cathode

V2a: 278 rail, 155.5 plate, 1.02 cathode
V2b: 278 rail, 155.5 grid, 157 cathode

V3a: 325 rail, 210 plate, 23.5 grid, 38.2 cathode
V3b: 325 rail, 208 plate, 24.5 grid, 38.2 cathode

V4 & 5: 468 plate, 460 screen, biased to 65%

Clone:
No v1a ("replicated" with a 220k resistor from rail to gnd)
V1b: 333 rail, 253 plate, 2.17 cathode

V2a: 357 rail, 198 plate, 1.32 cathode
V2b: 357 rail, 198 grid, 200 cathode

V3a: 357 rail, 239.5 plate, 24.5 grid, 39 cathode
V3b: 357 rail, 225 plate, 25.5 grid, 39 cathode

V4 & 5: 482 plate, 480 screen, biased to 65%


Still proceeding with the board swap, if for no other reason at this point than I still much prefer how my clone sounds / feels, and replacing the 1987's PCB will make it SO much easier to work on.

Obviously there is no voltage dropper resistor between V3 and V2 in Clone and it explain some of the higher V2 and V1 voltages.

 

[Matthews Guitars]

Guess what happens when someone gets REALLY curious about the notion that "different capacitors sound different" and goes beyond accepting the dogma and actually pursues scientific inquiry into the subject?

He discovers that capacitors of the same measured VALUE will plot the same, have the same frequency response, and sound the same as each other across the audio band.

There's a video about it on youtube. I'll try to find it.

 

[knulp]

Well,then report when done!

Go for a tone you like based on earlier plexi and fine tune with caps of choice..nice project!

Try to accommodate for the inherent character of the amp ‘cause of transformers and all instead of trying to replicate the clone..
I bet you’ll have a different and equally loved amp

And..work on the aesthetic of the clone..I’m now curious so maybe some pics posted here would be nice…

Good luck!

 

[TheMagicEight]

Guess what happens when someone gets REALLY curious about the notion that "different capacitors sound different" and goes beyond accepting the dogma and actually pursues scientific inquiry into the subject?

He discovers that capacitors of the same measured VALUE will plot the same, have the same frequency response, and sound the same as each other across the audio band.

There's a video about it on youtube. I'll try to find it.

Sounds right up my alley if you can find it!

 

[knulp]

Guess what happens when someone gets REALLY curious about the notion that "different capacitors sound different" and goes beyond accepting the dogma and actually pursues scientific inquiry into the subject?

He discovers that capacitors of the same measured VALUE will plot the same, have the same frequency response, and sound the same as each other across the audio band.

There's a video about it on youtube. I'll try to find it.

I just always suggest to put Mallory because of the material,that makes a difference..like ceramic vs mica..
But you are right sir..and I would be happy with just a good design and any adeguate choice of caps!
In fact if I had a 1987x I probably would not even mess with Mallory..I would do only in a boring autumnal sleepless night with nothing better to do at night..

 

[V-man]

I don’t think the differences you are hearing are due to lower quality components in the 1987x.
…
We are talking about two different amps and your preference between the two.

Elegantly laid out reasons how the OP does not deliver.

One cannot indict the components (anywhere) on a 1987x for “inferior sound” compared to an amp that does not conform to the spec of the 1987 circuit.

It is valid to say “I am surprised I found my clone(-ish) amp to sound better than the actual Marshall” but you don’t compare Apples to Friedmans (or any other “based on” spec that does not actually conform to the 1987 spec) to postulate how the 1987 components fail to deliver “1987-ly.”

The dead giveaway IMO was the “Transformer swap changed the sound but only marginally” comment. If the transformers deliver “slight differences” and still inferior at that, the idea that a tagboard would make a bigger difference seems ludicrous.

 

[scozz]

All new and old production Marshalls are made of very cheap components. This applies to all price categories, including the top dollar amps. It always makes me smile when people talk down the cheaper models, without realizing that their much more expensive amps are built just as cheaply. In the Marshall world there's no such a thing as an entry level or a high end model. All their amps are the same level of cheap. The actual pricing is driven by marketing and popularity.

I think this is true for the most part, but I also think the more vintage the circuit the higher the price.

And of course, the made in England Marshall’s are naturally going to be more expensive, because of labor, taxes, insurance etc. They are just inherently more expensive to manufacture, quality itself has little to do with price for the most part I think.

I think Marshall, as a historic Brand, has earned the right to charge more for vintage sounding amps.

Just my of course.

 

[TheMagicEight]

Elegantly laid out reasons how the OP does not deliver.

One cannot indict the components (anywhere) on a 1987x for “inferior sound” compared to an amp that does not conform to the spec of the 1987 circuit.

It is valid to say “I am surprised I found my clone(-ish) amp to sound better than the actual Marshall” but you don’t compare Apples to Friedmans (or any other “based on” spec that does not actually conform to the 1987 spec) to postulate how the 1987 components fail to deliver “1987-ly.”

The dead giveaway IMO was the “Transformer swap changed the sound but only marginally” comment. If the transformers deliver “slight differences” and still inferior at that, the idea that a tagboard would make a bigger difference seems ludicrous.

Wow, thanks for coming in to clear that up for me. I'll be sure to put future comments through my legal team.

If you would, though, have a look through my past comments and point out where I claimed the low quality caps caused the difference in sound?

 

[proxy]

Drink 12 beers, pick the guitar back up and none of this will even matter anymore ( at least for that day lol)

Would you be able to play well after 12 bears?

 

[knulp]

I get what you're saying, but do you think V1a is that important?

Actually if you want to experiment there is a more effective way to get a plexi style input stage using only one triode.Marshall used an input network in the jtm1h for that purpose..very nice..PM if you want the schematic..it’s just a few caps and resistors..but I don’t consider it an essential part of the plexi circuit..I made 3 amps just like you did skipping one triode and the input mixer and I’m satisfied with the results