hi, i just wanted to ask if there can go something wrong if connecting the parallel loop's input and output on my Marshall JCM 600 with a patch cable and using it as an additional gain stage. Is there also a difference if using a shorter or longer cable? and also, i checked out the tubes in mine...the power amp tubes are two JJ's and in the preamp i noticed fender tubes....if you have any suggestions to make my amp even more "marshally" with retubing i'd be happy getting some advice. thanks, bye
Marshall trick
- Thread starter rocknroll
- Start date
JammerMatt
New member
Re: Marshall trick
I don't know anything about the JCMs, but so far my experience has been that a well placed pedal (a tubescreamer or something along those lines) in front of the amp, with the pedal's drive dialed low, and the level dialed high hits the amp's front end harder resulting in a good increase in drive without coloring the sound too much. This would be a more standard approach than placing a drive device in the other loop I would think. Just my opinion.
If I'm wrong, that's okay, any of my bro's can go ahead and give better advice if they have it.
Don't know anything about the tube question, tho.
I don't know anything about the JCMs, but so far my experience has been that a well placed pedal (a tubescreamer or something along those lines) in front of the amp, with the pedal's drive dialed low, and the level dialed high hits the amp's front end harder resulting in a good increase in drive without coloring the sound too much. This would be a more standard approach than placing a drive device in the other loop I would think. Just my opinion.
If I'm wrong, that's okay, any of my bro's can go ahead and give better advice if they have it.
Don't know anything about the tube question, tho.
greendy123
New member
Re: Marshall trick
Do you know what type of tubes it has, such as EL-34, El-84's? JJ's are just a brand, but they should be good enough for the marshall sound. For the preamp tubes I would suggest tung sol 12ax7 tubes.
Do you know what type of tubes it has, such as EL-34, El-84's? JJ's are just a brand, but they should be good enough for the marshall sound. For the preamp tubes I would suggest tung sol 12ax7 tubes.
Re: Marshall trick
the power amp tubes are el34....but i'm not so much concernded abut them, they still sound good, i'm more conspicious about the fender preamp tubes....also someone mentioned that the tube in V1 position makes the biggest difference in sound, is that true? bye
the power amp tubes are el34....but i'm not so much concernded abut them, they still sound good, i'm more conspicious about the fender preamp tubes....also someone mentioned that the tube in V1 position makes the biggest difference in sound, is that true? bye
wixedmords
New member
Re: Marshall trick
I have heard about jumping the loop on a JCM600/JTM series. I don't have an answer for you about the cable, but it may not matter between a 2 footer or an 8 footer, but a 20 footer may cause an issue. My JTM622 has a bias pot that is a bit hard to find, it is on the side of the chassis, a little blue pot. I have JJ E34L's in mine. I like the sound of the amp. Marshally usually means Chinese tubes, but Marshally means different things in different eras. Tubes are really a personal preference, and there is no magic formula, just buying and trying, mixing and matching. What one guy finds as great, the next finds as horrible.
I have heard about jumping the loop on a JCM600/JTM series. I don't have an answer for you about the cable, but it may not matter between a 2 footer or an 8 footer, but a 20 footer may cause an issue. My JTM622 has a bias pot that is a bit hard to find, it is on the side of the chassis, a little blue pot. I have JJ E34L's in mine. I like the sound of the amp. Marshally usually means Chinese tubes, but Marshally means different things in different eras. Tubes are really a personal preference, and there is no magic formula, just buying and trying, mixing and matching. What one guy finds as great, the next finds as horrible.
Last edited:
greendy123
New member
Re: Marshall trick
Yup the V1 position thats the tube closest to the input. It might be hard to hear a difference between tubes, but the jump away from the fender tubes might be more noticeable. I would just get a bunch of tubes and try them out in the first position.
Yup the V1 position thats the tube closest to the input. It might be hard to hear a difference between tubes, but the jump away from the fender tubes might be more noticeable. I would just get a bunch of tubes and try them out in the first position.
devastone
Well-known member
Re: Marshall trick
As long as they are 12AX7s, which I'm sure they are, it doesn't matter what brand they are. There are better ones than others, and they all have a slightly different sound, but the fact that yours have a Fender stamp on the side doesn't make it sound more like a Fender or less like a Marshall. You won't get it to sound more "Marshally" by using a different brand tube.
As long as they are 12AX7s, which I'm sure they are, it doesn't matter what brand they are. There are better ones than others, and they all have a slightly different sound, but the fact that yours have a Fender stamp on the side doesn't make it sound more like a Fender or less like a Marshall. You won't get it to sound more "Marshally" by using a different brand tube.
Re: Marshall trick
ok, thanks for the info, i would also like to ask about the speakers... i was looking at eminence legend gb12....so i thought maybe change them with current celestion heritage, but then a friend said to "shorten" the combo, turning it into a head to drive a 4x12 cab... would that "shortening" really be necessary? (although, the amp sounds heavenly through a 4x12 1960 cab, but it's maybe just the speakers)...anyway, thanks again, bye
ok, thanks for the info, i would also like to ask about the speakers... i was looking at eminence legend gb12....so i thought maybe change them with current celestion heritage, but then a friend said to "shorten" the combo, turning it into a head to drive a 4x12 cab... would that "shortening" really be necessary? (although, the amp sounds heavenly through a 4x12 1960 cab, but it's maybe just the speakers)...anyway, thanks again, bye
stevie_bees
Cat In The Hatministrator
Re: Marshall trick
The patch cable trick was actually something recommended by Marshall with the TSL 122/100. It's not going to be an extra gain stage, but you can set the FX loop with a slightly different volume level, and switch it in and out for a volume boost.
Edit: I don't see any reason why it shouldn't work for the JCM 600.
The patch cable trick was actually something recommended by Marshall with the TSL 122/100. It's not going to be an extra gain stage, but you can set the FX loop with a slightly different volume level, and switch it in and out for a volume boost.
Edit: I don't see any reason why it shouldn't work for the JCM 600.
devastone
Well-known member
Re: Marshall trick
A combo cabinet's response is very different from a 4-12, or 2-12 for that matter, closed back cabinet. So, a combo will never sound like a closed back cab. The GB12 is a nice speaker, I use some of them, but the Heritage is as good, neither will give you that closed back cabinet sound out of an open back combo.
There is no need to shorten the amp, just unplug the internal speaker when you are using another cabinet. Instead of changing the speaker, if you don't have a 4-12 cabinet right now, I would suggest looking at an Avatar 2-12 or 4-12, lots of bang for the buck with those.
A combo cabinet's response is very different from a 4-12, or 2-12 for that matter, closed back cabinet. So, a combo will never sound like a closed back cab. The GB12 is a nice speaker, I use some of them, but the Heritage is as good, neither will give you that closed back cabinet sound out of an open back combo.
There is no need to shorten the amp, just unplug the internal speaker when you are using another cabinet. Instead of changing the speaker, if you don't have a 4-12 cabinet right now, I would suggest looking at an Avatar 2-12 or 4-12, lots of bang for the buck with those.
