#1
Hi guys,

So lately I've been having problems with my marshall jcm 800 model 2205, specifically getting a clean sound. Even though sometimes I use the clean channel I mostly play through the boost channel with the gain really low, around 3, to get an "almost breaking up" clean sound.

But the problem I'm having is that the amp (regardless of channel) gives me some horrible clipping when i turn my preamp section up (I need to do this since I'm using low gain, otherwise the amp isnt loud enough even with the master at full).

In my profile there are two mp3 files demonstrating the difference. One clip has the preamp vol at around 7-8 and one has it around 4. The one with the high preamp volume sounds like crap (at least to my ears). So if you could take 2 mins to listen to the clips and tell me your opinion, I'd really appreciate it. Also if someone thinks there's nothing worng with the amp let me know, maybe the amp itself sucks (doubt it but who knows)

Here are some specs on the amp:
JJ KT88 power tubes
12ax7 preamp tubes

celestion gt12-75 16ohm speakers (weird thing is they say they are 15ohms on the back but this model speaker is 16 ohm.)

if you need any other info let me know.

Thanks!
#3
the tubes are about a year old, and have been used very little. I'm at college and my amp is back home so I only get to use it about 3 or 4 months out of the year.

Anybody have any other ideas?

Any amp experts out there?
#4
The early version of the 2205 use's transistors for switching to the lead and clean channel. The issue with transistor switching is at higher volume levels, the channels tend to bleed into each other. Which is what is causing your issue. It was a poor design by Marshall and was later fixed on later 2205 models.

So your pretty much going to have to live with it or send it to a Marshall tech to get it fixed.
#5
Thanks ibanezpsycho, I am aware of the channel bleeding issue, I just never thought it caused the channels to sound completely sucky. I can hear the clean channel bleed into the boost when i turn the volume up on the clean channel but the bleedover goes away (maybe Its there but I just cant hear it) when i turn down all the controls on the clean channel.

My question is, do you think the bleedover is still going on even with the clean channel all the way down? Also, why would this cause the boost to sound like crap? shouldnt I just hear part of the clean channel coming in normally instead of all crappy?

thanks again.
#6
Quote by rnelson
Thanks ibanezpsycho, I am aware of the channel bleeding issue, I just never thought it caused the channels to sound completely sucky. I can hear the clean channel bleed into the boost when i turn the volume up on the clean channel but the bleedover goes away (maybe Its there but I just cant hear it) when i turn down all the controls on the clean channel.

My question is, do you think the bleedover is still going on even with the clean channel all the way down? Also, why would this cause the boost to sound like crap? shouldnt I just hear part of the clean channel coming in normally instead of all crappy?

thanks again.


Bleedover is going to be apparent even when you cant hear it. So even with everything down you will still get some bleedover. And think about it, if your Gain channel is bleeding over into your clean channel what do you think is happening when you switch back over to your gain channel. Its still bleeding over, you just cant hear it because your not using that channel. So your other channel is pretty much sucking the life out of tone.