PTP Board Kit for Bluesbreaker RI, which one should I buy

[SweetPickleSalad]

Hi,

I have a Marshall 1962 Bluesbreaker Reissue from 1993. The edition I have is the JTM 2*12 combo, 50w with tremolo.

I am considering installing a PTP board kit, but I am not quite sure which one to get.

Metropoulus offers these three variants:

BB Reissue PTP Board Kit
http://metroamp.com/store/product_info. ... cts_id=329


Metroamp JTM 45 Retrograde Kit
http://metroamp.com/store/product_info. ... cts_id=190

Metroamp PTP JTM 45 Reissue Board- Kit
http://metroamp.com/store/product_info. ... cts_id=192



BB Reissue PTP Board kit

Looks like this is the way to go for me but the kit only comes with layout diagrams and schematics, not step by step instructions like the other kits, which may represent a problem for me. But all in all I'd say this is the kit I should use and then add the 16*16 and 32*32 can capacitors to the kit.

Also does anyone know if the components listed below have been switched in order to meet the BB's vintage specs or if I have to order these separately?

Cap (C3) from 330uF to 250uF
Resistors (R16, R18) from 470k to 270k ohm
Cap (C6) from 220pF to 500--550 pF
Cathode resistor R15 from 1k to 820ohms.



Metroamp JTM 45 Retrograde Kit

Could also be the right way to go since I can order it minus tubes. It comes with an assembly diagram which may be helpful.
But if I use this kit, I will lose the Tremolo channel right? Not that I really use the tremolo channel, but will it represent a problem considering which amp I am going to modify?

Metroamp PTP JTM 45 Reissue Board Kit

Seems to be the same kit as Metroamp JTM 45 Retrograde Kit, less tubes, less can capacitors less bright cap right?



So, could anyone give me advice on which kit to buy to receive the best possible match and which kit will bring me the closest to the original BB specs?
My amp is currently running on KT66's by the way, so the re-tubing part is done. I have also removed the bright cap on the channel 1 volume pot, major mods right there man .


Many thanks,
/fredrik

[Mars Hall]

You need to decide if the tremolo circuit is a must. The JTM stuff do not have that circuit. I'm currently saving up to do the same project.

I've decided to go with the BB kit, just because I want everything to work, that the amp came with. They say the tremolo circuits on these amps are not stellar, although George has tweeked the circuit, in his kits, to get the most out of them.

Don't let the lack of "step by step" instructions scare you off the BB kit. The layout diagram is enough to pull you through. If a question or problem pops up, most members here are welling to help us out.

The BB circuit is identical to the JTM45 circuit except for the added tremolo. George designs these kit as close to original circuits as possible. Once you build this, it'll be like, going back in time.

The only other upgrade I'll suggest is the OT. I makes a big difference in getting these amps closer to original specs. Some say to change the PT as well, but it can be changed easily enough later, if you feel the need. It makes more since to change the OT while you have the board out of the way.

Hope this helps.

[SweetPickleSalad]

Thanks for the info!

I believe I'll go down the BBRI board kit road too. I'll let you know how this little project turns out.

I checked my OT and PT and they were manufactured by Drake, don't know if that's good or bad, I'll let that little project rest for a while though. Right now I'll concentrate on the ptp board.


/Fredrik

[908ssp]

The transformers make a bigger difference than the board.

[neikeel]

+1 on the trannies

I was very disappointed in my RI rebuild.

Best value was (in order)

1) Mullards or good NOS preamp valves

2) Good transformers

3) PTP board

I ended up putting mine back to stock except for PTP board and selling it

My scratch one sounds much better with my choice of trannies.

It was the way I got hooked here

[VelvetGeorge]

All great replies. The trem is the deciding factor. And it's worth mentioning that it really isn't improved by changing to the PTP board.
I was talking to Don Butler about this at the LA amp show recently and he still agrees that the original Marshall trem circuit only works with an original 3G274 transistor.
The RI circuit is pretty sterile, even when optimized.
For the record, I used the RI circuit for compatibility with modern FET's.

Agree 100% that the improvements, in order are:

Tubes

transformers

signal path (with or without the PTP board) tied with circuit accuracy


VG

[Mars Hall]

All great replies. The trem is the deciding factor. And it's worth mentioning that it really isn't improved by changing to the PTP board.
I was talking to Don Butler about this at the LA amp show recently and he still agrees that the original Marshall trem circuit only works with an original 3G274 transistor.
The RI circuit is pretty sterile, even when optimized.
For the record, I used the RI circuit for compatibility with modern FET's.

Agree 100% that the improvements, in order are:

Tubes

transformers

signal path (with or without the PTP board) tied with circuit accuracy


VG

In about a week I'm going to purchase the PTP BB RI board kit. I enjoy using the tremolo circuits on my Fender amps. How difficult would it be to install a Fender style tremolo circuit, in place of the cheesy RI circuit?

[Puerco]

In about a week I'm going to purchase the PTP BB RI board kit. I enjoy using the tremolo circuits on my Fender amps. How difficult would it be to install a Fender style tremolo circuit, in place of the cheesy RI circuit?

That's what Ceriatone does and (at least in their implementation) it doesn't work at all.

[VelvetGeorge]

If you want to do a better circuit, I would look at Vox. And search for an original transistor.

George

[Mars Hall]

If you want to do a better circuit, I would look at Vox. And search for an original transistor.

George

Is it that a Fender Trem circuit does not marry well to the Marshall preamp circuit? The Vox trem is a better fit?

My goal, if possible, would be the Trem circuit from my 61 Concert amp, in my BB RI. I sounds more like a Uni-vibe, that's the sound I would be after.

[SweetPickleSalad]

Got my BBRI PTP board kit the other day and I am all excited to get it done and installed.

Caps, resistors etc are all soldered in place. Bottom and buss wiring done, all I gotta do now is to install the board in the Bluesbreaker.
I guess the easy part is done, hopefully I'll be able to get all them wires in the Bluesbreaker connected to the right slot on the ptp board.

I'll let you know how it goes, I'll post pictures and sound samples when I am done

George:

I noticed that the parts list you have for the Bluesbreaker Reissue PTP board kit doesn't correspond with the pictures that are on the installation CD. According to the pictures there should be 7 Metal Oxide 2 watt resistors, your parts list contains only 6 Metal Oxide 2 watt resistors, actually 100k resistor short.

I am not the best in the world reading schematics, but I'll check towards that later on.

Anyhow, I am a happy camper so far and I wish I'll get the board installed during the weekend.

/Fredrik

[VelvetGeorge]

Thanks for the update. A few others have pointed this out and it now corrected.

I have someone working on full diagrams for the BB RI board. I'll get those posted as soon as we have them.

george

[Mars Hall]

Thanks for the update. A few others have pointed this out and it now corrected.

I have someone working on full diagrams for the BB RI board. I'll get those posted as soon as we have them.

george

George, do you have an eta for the full diagrams? Will they appear on Wiki? I ordered my kit, ot and choke this morning.

[VelvetGeorge]

I don't have an ETA, but I'll check on it. Maybe give a polite nudge.

Bard layouts are next on my list to upload to the wiki. It just takes a while because I have to convert file type and size.

Hope to have them up this week.

VG