Marshall AVT modifications

[Bear62]

Thanks to all the replies... positive and negative. To answer some questions, my AVT50 is a Valvestate 2000. It has one tube in the pre-amp and the power amp is solid state.

 

When I first got the amp, I thought it sounded flat and dead with little tonal response. When I changed out the tube to the Groove Tube ECC83, it made a noticeable difference. However, when I got ride of the stock "custom voiced" Celestion and added an Eminence Governor, the tone from the amp was actually impressive.

 

I would still rather own a DSL or a JCM800 but my modded AVT will suffice for now.

 

--Dennis

[HELSTRUME]

Slap an EQ in the loop also.

[dd-6eDQx]

This is a terrible amp. Unlike one reviewer, the guitar center people told me I should NOT have bought it. And they were right. I would consider this an over-sized practice amp. The sound can't cut through anything. The foot-switch--should you lose it--is almost impossible to replace. (I did replace mine, and it was a hassle-and-a-half.) I took it to a live gig once; after that, I talked every other band into letting me use one of their amps until I could buy my own. I sold it as soon as I could and bought a Music Man. Been playing that since and never looked back. Terrible, terrible, terrible amp. Not for gigging.

[BlackBelt]

Man, what an old thread! I know they dont get much love from most guitarists, but I use 2 AVT50h amp heads running through 2 stock speaker Marshall 1960a cabs, or 2 Marshall 1936v cabs if its a smaller gig. I only use the clean channels on the avt50's, and both have had the recommended mods done to the heads --reverb disabled so that the reverb knob becomes a presence control, and replacement of that one resistor that Marshall recomends changing to prevent overheating and shutdown. I only use the amps for clean power as all my effects are on my pedalboard. I've got the new Marshall DSL100h heads, and they sound absolutely incredible. But they are VERY, VERY heavy (they are in touring grade road/flight cases) so for most smaller gigs I just pull the AVT50's off the truck. In my opinion they are best suited to being used for clean power only. With the mods done to them they are decent clean amps, but pedals really are a neccesity.

[clara bess]

I almost sold my AVT now I have two combos - AVT50 and AVT20. To make this amp sound better:

1) Get rid of the stock speaker and swap it out to your favorite 8 ohm speaker

2) Open the back slightly - Two 2-1/2" holes or remove about 2-1/2 inches off the bottom of the back.

3) Plug a jumper (like you use betwen pedals) from the Emulated Out to Effects Return or if you have the AVT20 Emulated Out to CD In

[WRGKMC]

I have a Valvestate 100 head I run with a 1960 cab with Celestion 75's Its sound very good considering it is solid state. Mosfets produce the best SS sound and mimic the feel you get from tubes. The preamp tube doesn't make allot of difference to the tone. Its used in the drive circuits and is likely a starved bias design. I tried out about 6 different tubes before settling with a JJ 5751 instead of a 12AX7. It gives a 30% gain reduction and helped with the crunch channels and tamed some of the high gain drive. I've used that live and many guitarists complemented the sound quality especially when they used it playing. I'd say the clean channel is the best. I used to use the gain channels but have switched to pedals for my drive. Not because it was bad, but it gets old quickly and I like variety.

 

Speakers are very important. The stock speakers aren't much to get excited about. The 100W head I have competes well running it along side a 50W tube head. I switch between using my old Black face Bassman 50W as a second amp and a Music Man 65W head which I run on a 4X10" cab.

 

A 50W Valvestate is more like a 25W tube head. I can see where a pair would be much better sounding. I probably wouldn't gig with less that 100W of Valvestate power and even then a very loud drummer will make you push them hard. If you use a very high efficient speaker with some British coloring the amps can sing and be a nice lightweight rehearsal amp. You'd likely have to mic it live. I have the 15W version for a Practice amp. I've used it a few times for rehearsals and had to crank it way up with allot of gain just to be heard.

 

I have heard the 100W twin Valvestates with good speakers and they do sound very good. I'd say over all, the Marshall SS amps sound allot better then most others out there including the Fender stuff. If you're comparing it to tube amps, then you're in a whole different category, however not all tube amps sound great and they do require regular maintenance. and the difference in cost is huge.

[TolerBear]

I know that the Marshall AVT amps do not get a lot of love here and I understand why as they are a bit pricey for the quality and features.

However' date=' I got a Marshall AVT50 combo amp off Ebay for $150. I first replaced the stock tube with a Groove Tube ECC83 and then I replaced the stock speaker with an Eminence Governor. IMHO, this improved the tonal qualities of the amp A LOT. I am not saying it is as good as a JCM or DSL, but for practice and small gigs, it is a pretty decent amp. Also, it does not get any where near as muddy with the volume and gained turned up as it did before my mods.

With that said, I would not be as happy if I had to pay the full price ($499) and then invest another $90 or so to make it sound decent.

Anyone else have any similar positive experiences with the Marshall AVT series?

Dennis [/quote']I have a Marshal AVT150H and I love the sound I get out of it and my 4x12 cab. In my cabinet I have 2 WGS Retro 30s and 2 Eminence Swamp Thangs. I run a BBE Sonic Stomp through the effects loop and I leave the Sonic Stomp on all the time when I'm playing. I use the acoustic simulator for my cleans unless I want a little different sounding clean channel. I use the OD1 channel for my rhythms and OD2 for my leads and I play metal. I cheat on the front end though and I use a Joyo Ironman Series Rated Boost for some clean boost. Over all I'm very happy with mine. \m/ :-)

[WRGKMC]

The Valvestates are highly underrated. I used to own a 50W plexi and the clean channel of the Valvestate matches its tone.

The Drive and Lead channels can be matched by other amps and pedals. I have a Marshall Governor that can be dialed up to match the Lead channel and a Marshall Bluesbreaker pedal that can match the drive channel to a dime.

 

I used to use the channel switching allot but mainly use the clean channel now because I have an extensive pedalboard I use for my sounds.

Using echo before the lead channel doesn't sound good because the echo gets destroyed by the drive. I can put my chorus and echo in the effects loop but I'm running two amps so I'm better off running clean and not worrying about getting my drive from the heads.

 

I also have a 15W Valvestate which I use mainly for practice. I wouldn't mind having a 30W or 50W for rehearsals. The 100W head and 1960 cab wont fit in my Mustang trunk so I usually use a 4X10 cab instead. a combo would be ideal however.