Marshall People...can you identify what Mod this is?

[smucarolina]

A guy offered me his 1959 SLP resissue. Here is a link to the ad for some pics of the outside of it.

http://dallas.craigslist.org/dal/msg/2137367554.html

Anyways...he says it has been modded. He told me a jumper mod and volume mod had been performed. I know what a volume mod is...but a jumper mod? He told me he thinks that Goodman music performed the modifications. He told me the store got bought out by LA Music or something of the sort. Anyways...can you tell me what modification this is and how it changes the amp tone and function?

I have pictures in my email of the guts of the amp. It seems to be a decent job. I will post pics ASAP.

Thanks!

 

[rupe]

I would guess the jumper mod is simply an internal jumper of the inputs like when you run a cable from high input II to low input I.

 

[Anonymous]

A guy offered me his 1959 SLP resissue. Here is a link to the ad for some pics of the outside of it.

http://dallas.craigslist.org/dal/msg/2137367554.html

Anyways...he says it has been modded. He told me a jumper mod and volume mod had been performed. I know what a volume mod is...but a jumper mod? He told me he thinks that Goodman music performed the modifications. He told me the store got bought out by LA Music or something of the sort. Anyways...can you tell me what modification this is and how it changes the amp tone and function?

I have pictures in my email of the guts of the amp. It seems to be a decent job. I will post pics ASAP.

Thanks!

Need gut pics or no one can tell you anything... That added pot could be anything...

Steve

 

[bubbastain]

 

[skoora]

Judging by the description the extra pot is probably a Master and like others mentioned it's been internally jumpered so no need to do it with a cord on the outside. Just a guess though on the Master. If this is on CL is it local to you? If so check it out. If it sounds good buy it. I definitely wouldn't pay $1000 for it though. 800 would be better

 

[steve_k]

Well, you can't have a master volume AND the two circuits jumped internally and be active at the same time. One or the other while plugged in.

There's a better one from Klark right now on the classifieds.

 

[skoora]

Well, you can't have a master volume AND the two circuits jumped internally and be active at the same time. One or the other while plugged in.

There's a better one from Klark right now on the classifieds.

Why do you say you can't?

 

[JerryP]

Sounds like the inputs are jumped internally and it has a PPIMV added.
Jerry

 

[cyndicate]

Looks like the youtube video is just some generic 1959 RI clip he found online? It's not even the same amp as shown.

Like others mentioned, probably need gut pics to figure out what was actually done to the amp.

 

[cyndicate]

Well, you can't have a master volume AND the two circuits jumped internally and be active at the same time. One or the other while plugged in.

There's a better one from Klark right now on the classifieds.

Why do you say you can't?

Confused by this statement as well

 

[smucarolina]

guts.

 

[skoora]

Looks like a pre PI Master, but I'm no pro. Just a guesstimator extraordinaire.

 

[smucarolina]

anyone else?

 

[FourT6and2]

Yes, looks like a pre-phase inverter master volume. Channels jumped internally. Looks like the V1 position on the board has been messed with as well. Not sure if this is part of the jumping mod, though. I've always wondered why people jump the channels internally when you can just do it with a short patch cable. It takes more effort to open the amp up and mod it than it does to just plug a cable in...

 

[skoora]

If it is a pre PI Master it's not going to sound very good on a 1959 circuit. A lot of the drive in that amp is from the PI being hammered by the preamp section. If you reduce your gain before the PI you'll get a cleaner sound as you reduce it. I believe they used this on the first 2204 in 1976 and it didn't go well on that amp either and changed it the next year. Again just fuzzy memories and recollections, adjust with the necessary amount of salt. I bet you could a bunch of info just doing searches, google, wiki etc.

 

[FourT6and2]

If it is a pre PI Master it's not going to sound very good on a 1959 circuit. A lot of the drive in that amp is from the PI being hammered by the preamp section. If you reduce your gain before the PI you'll get a cleaner sound as you reduce it. I believe they used this on the first 2204 in 1976 and it didn't go well on that amp either and changed it the next year. Again just fuzzy memories and recollections, adjust with the necessary amount of salt. I bet you could a bunch of info just doing searches, google, wiki etc.

The master-volume models (dual inputs) have pre-phase inverter masters. I don't think they ever had post-phase inverter masters, though...

I like the PPIMV I put in my 1959. It doesn't sound all that good at low, bedroom-level volumes. I think it's intended design purpose was to tame a LITTLE bit of volume. i.e. at 9:00 it's harsh and fizzy. But when 3/4 of the way up it sounds great and the amp is still playable without making your ears bleed. But, it's WAY too loud to play outside of full band situations. I view this type of master as a leash to tame the beast, not a cage to contain it.

I was going to try a pre phase inverter master before installing the PPIMV, but many people said it was a waste of time as it would sound like shit.

 

[skoora]

Yeah, I know the 1st year 2204 had a MV circuit that got changed within the year I think for not being as nice as the one in the 2203. Or it might be the other way around where it was the 2203. Unfortunately I can't remember which circuit it was, whether it was pre or post. I imagine pre as I played one and the Master had to be up for the overdrive to start filling out nicely.

Just did a little digging and found out the first 2204's didn't have a cascaded input stage (3 vs. 2 for the 1959) like the 2203. Which is why they sounded a little anemic if the Master was low being a pre PI master.