Mark III troubleshooting

[cblais]

I picked up a blue stripe (simulclass, reverb, EQ) about 6 months ago. Although I've been playing for 15 years, it is my first amp. I've logged about 8 hours on it because it's so **** loud and we just had a baby.

I just finished doing the R2 mod using a stacked pot (outer ring for presence; inner ring for R2 volume). That makes things better.

I must say that overall, I'm quite unimpressed with the tones I'm getting. I bought it thinking that I could get nice early-Metallica type tones at low volume (think .25-.75 on the master), but even around 1.5-2 the amp seems to lack balls. Anything above that is ridiculously loud for the apartment. As much as I'm not a fan of most amp modeling, I get considerably better tones with modelers such as Guitar Rig, Amplitube, Pod Farm, etc. playing through my computer speakers.

I tried using some Master of Puppets settings that I downloaded (and many people with Mark IIIs agree sounded "like the album"), but it just wasn't there for me.

Is there something wrong with the amp, or am I just retarded?

Also, the reverb seems to not be working. I've tried swapping the gray and white wires, changing the tube, soldering the grounds together (http://forum.grailtone.com/viewtopic.php?f=27&t=38458&p=276811&hilit=reverb#p276811), checking that it is ~200 Ohms (it's 207) etc. If I jiggle the box, I can hear the springs amplified through the speaker regardless of grey/white wire position.
Any tips on fixing the reverb would be appreciated, especially if I end up selling it.

 

[dgr888]

Check inside the reverb tank itself and see if the green and black wires on either of the jacks are broken. Usually that is the problem for the reverb most of the time. Also you could check my post about the reverb hum fix that usually happens with these and correct it while you have it apart. Don't solder the grounds together as this will just introduce more hum in the reverb. As far as being retarded I don't thinks so. In order for these amps to sound good they have to be pushed to louder than apartment levels and the only way to achieve that would be be with a good output attenuator on the speaker such as a THD Hotbox or something like that.
Hope this helps.
Dan

 

[JOEY B.]

I must say that overall, I'm quite unimpressed with the tones I'm getting. I bought it thinking that I could get nice early-Metallica type tones at low volume (think .25-.75 on the master), but even around 1.5-2 the amp seems to lack balls.

What led you to believe you could get the Metallica sound (I have a hard time using the word tone when speaking of them) at such a low volume?

I tried using some Master of Puppets settings that I downloaded (and many people with Mark IIIs agree sounded "like the album"), but it just wasn't there for me.

Do you have a combo or head? Which speaker(s)?

Get a new reverb tank: Accutronics model# 9AB2A1B

 

[cblais]

Thanks for the Christmas day feedback!

Check inside the reverb tank itself and see if the green and black wires on either of the jacks are broken. Usually that is the problem for the reverb most of the time. Also you could check my post about the reverb hum fix that usually happens with these and correct it while you have it apart. Don't solder the grounds together as this will just introduce more hum in the reverb. As far as being retarded I don't thinks so. In order for these amps to sound good they have to be pushed to louder than apartment levels and the only way to achieve that would be be with a good output attenuator on the speaker such as a THD Hotbox or something like that.
Hope this helps.
Dan

I had the reverb box open and didn't notice any broken connections. If something was open, would I still get so close to 200 Ohms from input to output? I did look at your post regarding the transformer hum. I don't remember hearing anything like that. When the reverb was working a day or so before I posted, it was acting more like a gain/volume control.

It seems unlikely that soldering the grounds would create a ground loop given the proximity of the rca plugs, but either way, that's not the problem.

I've thought about getting a THD HotPlate, but it's tough to spend $240+ used when most reviews say master volumes are much better then the -16dB setting I'd be using.

What led you to believe you could get the Metallica sound (I have a hard time using the word tone when speaking of them) at such a low volume?

I bought the amp for its versatility, and the fact that it is supposed to sound reasonable, not amazing or anything, at lower volumes. Metallica sound at very low volumes would have definitely been a bonus, but I figured that by 2.5-3 I should get something reasonably close (especially considering the manual suggests that the master volume shouldn't need to pass 5 or so. Like any tube amp, it sounds better loud, but I have yet to be amazed, or even impressed, by anything other than how loud it can get (I've never put it past 3).

I expected an amp with 2 solid channels (not necessarily at the same time). I expected to tinker a lot to learn the interactions between the controls. But, even with the sample settings in the manual, my wife says it sounds like ****. I think it sounds like a cheap (<$150) SS amp. I got better sound using a used $80 squire through a Blues Deluxe Reissue at GC with about 10 seconds of tinkering (is that prohibited to say in this forum)

I have 3 electric guitars:
Parker Fly deluxe (hardly a metal guitar, but it plays amazing)
ES-335 clone with weak single coil pickups (~4K or so), surprisingly bluesy sound.
Home made strat clone w/an oak body (I made it from scratch in 1997 or so long before more traditional tonewoods were readily available on the internet) and 2 dimarzio humbuckers wiring with push-pull pots for coil splitting (sounds better than I expected).

I also have an Agile AL-3100 Les Paul clone in the mail. From what I've read, it should have near-Gibson quality sound.

If I can't make the Mark sound decent with any of these at a reasonable volume, I'll probably have to sell it before ever getting a chance to really use it, or more ideally trade it to someone in the SF bay area

Do you have a combo or head? Which speaker(s)?

I have a 1x12 combo. It says EVM MODEL 12L OEM TYPE on the back of the speaker.

 

[dgr888]

Yes and Merry Christmas to you. I'm sorry that no wires were broken in your tank because that would have been the most likely source of the problem with it not working. I don't have any other ideas as to what could be wrong except for a bad tube or the reverb trans is out. I have two Mark 3's myself and I agree they sound like **** at low volumes and the only way I have found they sound good is at cranked up levels or through an attenuator. Also if you notice one of the cables to the reverb is shielded and the other is a plain wire with no shield and if you do tie the grounds together you absolutely will get a ground loop that comes in through the chassis. If you do get the reverb working turn it's volume up and with the tank sitting the way it comes from the factory and listen. Then do the mod and there is a very noticeable difference. At any rate good luck and I hope you can get it figured out.
Dan

 

[cblais]

I don't think it's a tube. I replaced it with a share and also swapped 1 and 4 and the amp still worked. If the tube was bad, putting it in 1 should essentially kill the amp right?

Is there an easy way to test the transformer? I have a multimeter.

Aren't the two grounds already connected by the amp's chassis? I know that ground loops are essentially the result of imperfect conduction, but it seems unlikely that a small wire is going to have much of an effect compared to the entire chassis. I must be missing something.

Is the input for the reverb tank on the amp towards the front or back? The manual only says "grey goes X", but I don't know if the previous owner swapped out tanks and replaced the wires correctly.

 

[Boogiebabies]

Where the red cloth lead off the reverb transformer connects to it's B+ supply there is a large 3W 120K resistor and a 1/2 Watt 33K resistor (R116) off the center
B+ voltage rail. The 33K sees the voltage first, but check that they are both good. More often the 33K turns brown and eventually burns out, thus no reverb voltage supply.

 

[JOEY B.]

Try these settings (lead channel) with the Treble, Master and Lead Master pulled. If I lower the 750Hz slider into the "Metallica zone", my C+ sounds like a cheap solid state P.O.S. too.

You will need to start with the Lead Master at ZERO and sneak up on your desired volume. DO NOT switch to the rhythm channel with these settings, as you will then know the meaning of loud. :shock:

The open back combo lets a lot of the speaker "punch" out of the back of the cabinet. It is not the best design for "heavy metal" rhythm playing. The presence on many Mark III's will need to be at 3 or lower when using the EV speaker.

 

[boogiemon]

definitely a hardware issue of some sort (tube probably) my mark III can sound extremely heavy at any volume.

 

[cblais]

Thanks for the suggested settings JOEY B. I'll try them later tonight if I get a chance. My wife was outside sweeping and my triplex is empty so I put the kids in our bedroom (other end of the apartment) and cranked the amp way up--something like 9.5-8-0-4-7-7.5-6. That sounded a lot better although my ear still hurts an hour later. I was only able to do it for able 5 minutes (awesome for the tubes) so I didn't get to tweak around too much. My wife was 80+ft away and I was in the house with all the doors and windows closed and she said it sounded like I was right beside her. Awesome.

Hopefully I'll have a chance to check those resistors on the reverb tonight as well.

definitely a hardware issue of some sort (tube probably) my mark III can sound extremely heavy at any volume.

I can make it sound heavy at low volumes, but it doesn't sound tight. I have an extra preamp tube and 2 6L6 tubes. Unfortunately, I don't have any extra EL84s to test it with. I guy I bought it from said they had less than 20 hours on it, so I would think they're fine (if you had decent sound and swapped in bad tubes wouldn't it be evident right away)?

Thanks for all the help, I'll keep you informed.

 

[boogiemon]

tight: keep the bass set at 1 & pull the "deep/master" knob.

Thanks for the suggested settings JOEY B. I'll try them later tonight if I get a chance. My wife was outside sweeping and my triplex is empty so I put the kids in our bedroom (other end of the apartment) and cranked the amp way up--something like 9.5-8-0-4-7-7.5-6. That sounded a lot better although my ear still hurts an hour later. I was only able to do it for able 5 minutes (awesome for the tubes) so I didn't get to tweak around too much. My wife was 80+ft away and I was in the house with all the doors and windows closed and she said it sounded like I was right beside her. Awesome.

Hopefully I'll have a chance to check those resistors on the reverb tonight as well.

definitely a hardware issue of some sort (tube probably) my mark III can sound extremely heavy at any volume.

I can make it sound heavy at low volumes, but it doesn't sound tight. I have an extra preamp tube and 2 6L6 tubes. Unfortunately, I don't have any extra EL84s to test it with. I guy I bought it from said they had less than 20 hours on it, so I would think they're fine (if you had decent sound and swapped in bad tubes wouldn't it be evident right away)?

Thanks for all the help, I'll keep you informed.

 

[milamatik]

I also got the blue stripe. The reverb won't work at low volumes.
It is (compared to my other amp: peavey classic) a weak reverb. But it will work with higher volumes. Just try it.

 

[edgecrusher]

I like to keep the bass and deep knobs pushed in as it keeps the bass tighter. I get great tones with my Mark III at low volumes. Try it through a closed back cab if you can,and I think you'll find the punch your looking for. A fresh set of tubes is also probably in order.