5150 loop?

[bsp01]

I'm sure people must be using processors with the 5150 (s) loop. However, I plugged in my trusty G-Major last night to the loop of my 5150 III and hit a snag... I get barely any level, even with the input range set to "consumer" as the internet says to do. I pretty much have to crank the amp to get a decent level into the G-Major. Sucks because one thing I didn't even consider with this amp was the loop since every review I read said the loop was fantastic; for pedals I guess.

From what I can figure out this is because the loop is "unbuffered" which doesn't mean a whole lot to me... it is worth noting though that I do get sound, and it's not bad, but I think it would be better to get more input.

Any suggestions or advice would be appreciated.

I was thinking of trying the preamp-out into the gmajor, plugging a dummy cable into the effects send, and gmajor out back into the 5150 effects return.. not sure if that would work as it seems like it should, or if there would any unforeseen problem with that idea.

 

[Anonymous]

haha... Ive asked so many questions about a 5150 over the past week that I might as well ask this one. Is it at all possible to just simply replace the loop on this amp with a metro loop or something to that equivalent? Or... does it require some modification, and simply cant just be swapped for a better effects loop? Sorry for intruding on your OP bsp01... but I am interested in getting one of my 5150's in decent shape to handle an effects processor as well.

 

[glpg80]

5150 and 5150 III loops are simillar and different at the same time,

for 5150's, the loop has nothing to do with buffering, because there are 5 stages of gain and a 6th stage of an inverted cathode follower, the loop has to compensate for this voltage gain somehow to prevent distortion, not the tubed type overdrive you're thinking of. therefore its a high output impedance stage and not a low output impedance stage by design which acts as a great current source, poor voltage source. a buffer serves a different purpose to create a low output impedance which mimic's the input signal close to unity, but as you already know there is no buffer opamp circuitry in this loop, its 100% tubed, and worth mentioning almost impossible to fix easily.

5150 III fixed this somewhat with a redesigned lead channel, but the loop is simply limited in design. what you need is a low output impedance line level to instrument level buffer immediately following the loop and before the g major II.

Its not the first time 5150 loops have come into question. but before you start buying more products, i would check that the g-major II is not defective - because 9/10 people have fixed that problem by changing to consumer which the g-major compensates for instrument and line level - if you are not hearing any differences, then you either have a fucked up g-major II or your gain levels are all out of whack in your settings, causing you to think something is wrong when it is not.