Mark IV Reverb question..

[3s-gte]

Hey,

I have been been using my Mark IV live for about 4 months and I LOVE it.
When I got it I installed new preamp tubes because it had some tone issues.
Now it ROKKS.. except for the reverb.

The reverb has always sounded.. well funny.. When I turn up the reverb, the tone gets really bright. Do they all sound like this or is mine sick ?

TIA.

 

[Russ]

Do you have the correct tube in it? The A version takes a 12at7 in the reverb circuit. The B version splits the reverb across a couple of 12ax7's. The 12ax7 will not sound right in the place of the 12at7 in the A version. Double check that you have the correct tubes in your amp.

 

[3s-gte]

Thanks for the reply.

Mine is the 'B' version made in 2002. I did double check the tubes to be certain they were both correct AND good.

 

[Russ]

If your tubes are fine and your cables are fine and you get reverb then there isn't much that can be wrong that you would be able to fix. Has the problem been consistent? How long ago did you start experiencing it? What hapened proir to and during the first time you experienced this? I find the reverb to be relatively weak on a Mark IV. I have never had it become bright. Too bad it is over 5 years old. It is out of warranty. You might have it looked at anyway. The common things like reverb tubes and cables are the typical fixes most can do on their own and fix about 90% of the problems people face. You might check your reverb pan itself but it sounds more like something is wrong in the circuit than the pan. Did you buy this amp new? Was it ever modded?

 

[fpoon]

You mean it gets really bright in the Lead Channel? That's normal I think. The first time I tried the amp and I had a high gain setting on my lead channel I got the same akward brightness when my reverb was on. I didn't know however that my reverb was set too high. It was like 5 and higher. Basically if your having the same problem I had, turn down the reverb on the lead channel to like 2 or 3 and as low or high as you want for channel 1 and 2.

Also I noticed if you strum your strings to hard the brightness can still be heard. Don't strike the strings too hard in the Lead Channel with the reverb on a high gain settings.

 

[psychodave]

Do you have the correct tube in it? The A version takes a 12at7 in the reverb circuit. The B version splits the reverb across a couple of 12ax7's. The 12ax7 will not sound right in the place of the 12at7 in the A version. Double check that you have the correct tubes in your amp.

The A version I just got had a 12AX7 in the reverb spot. I switched it to a JAN Philips 12AT7 and the amp sounds better.

 

[Russ]

Yeah, the A version gets a little too much gain in the reverb with a 12ax7 in the reverb position. It makes it sound a little odd.

 

[3s-gte]

Its gets really bright in general when i turn up the verb.. I never run much reverb.. just a tiny bit at rehearsal. (when i dont have any ambient fx with me..)

I may need to hook up another reverb tank and see if it sounds funny too.

thanks for the help guys.

 

[mr_fender]

Weak reverb on a mark IV???

I have a 91' mark IVa and when the reverb is on 10 it is drenched in thick beautiful reverb ala Dick Dale.

To me the reverb has a bit of a "bright" sound to it, but that is often the nature of the beast. Spring reverb units often have the bass filtered out a bit to keep the springs from getting slammed with low frequencies, making them rattle and such. Keeps you from getting that irritating, loud "boing" rattling sound each time you hit a hard note or chord.

I love the sound of the Mark IV's reverb. Sounds a bit like a Fender twin's reverb to me, adding a sweet, hazy, harmonic chime to clean tones especially.

The only beef I have with my Mark IV's reverb is the fact that the reverb circuit is BEFORE the fx loop. That means if you put a volume pedal or tremolo in the FX loop it also effects the reverb and sounds very unnatural to me. I prefer to have the reverb trail off when I use a volume pedal or tremolo.

Does anyone know of any mods to move the reverb behind the FX loop?