Search found 14 matches

by SquierJVs
Wed May 22, 2019 8:22 pm
Forum: Mark Series
Topic: Mark IV with 6V6 - Triode? Pentode?
Replies: 5
Views: 576

Re: Mark IV with 6V6 - Triode? Pentode?

Excellent.

Thank you for that clear explanation.

Off to my local music shop to pick up the Mesa 6v6's I ordered. :-)
by SquierJVs
Mon May 20, 2019 11:57 am
Forum: Mark Series
Topic: Mark IV with 6V6 - Triode? Pentode?
Replies: 5
Views: 576

Re: Mark IV with 6V6 - Triode? Pentode?

Well the manuals are very clear ... TWEED and SIMUL-CLASS _only_ with 6V6's (and all 4 need to be 6V6's).

But the selection of Pentode vs Triode is independent of Simul-Class and Tweed settings.

My question is whether there is a restriction? Or is just the guitarist's choice?
by SquierJVs
Sat May 18, 2019 4:24 pm
Forum: Mark Series
Topic: Mark IV with 6V6 - Triode? Pentode?
Replies: 5
Views: 576

Mark IV with 6V6 - Triode? Pentode?

Hello all, I've read the user's manual for both the Mark IVa & IVb. Both have the same info regarding the use of 6V6: - "four 6V6's can also be used in the MARK IV ... but, ONLY when TWEED and SIMUL-CLASS are selected" But nothing is said about the use of Pentode vs Triode modes. Does anyone know if...
by SquierJVs
Wed Jul 26, 2017 10:27 pm
Forum: Vintage Amps (Before 1991)
Topic: Bass Knob sensitivity on Mark IV Lead Channel
Replies: 9
Views: 3150

Re: Bass Knob sensitivity on Mark IV Lead Channel

Hello thecordova, If I understand your question correctly, you are trying to determine if the Bass control on the Lead channel of your amp is behaving "normally". I think it depends on the amount of Gain & Drive you have configured. I have the same amp and I ran a few experiments. With high values o...
by SquierJVs
Sat Jul 15, 2017 2:51 pm
Forum: Mark Series
Topic: Mark III replacement pots
Replies: 2
Views: 1030

Re: Mark III replacement pots

Hello, Call Mesa directly and ask for that part number. You may wish to purchase other front panel pots as well. My experience with a MkIVa was that when one goes, the other are not far behind. Also, you may save on freight/mail costs. (And on time ... once you have the chassis out and on the bench,...
by SquierJVs
Sat Oct 01, 2016 7:42 pm
Forum: Vintage Amps (Before 1991)
Topic: MK IV rev A manual? Weird jack on the underside...
Replies: 2
Views: 1433

Re: MK IV rev A manual? Weird jack on the underside...

Hello fantomaz, During the 90's, the Satellite 60 and Simul-Satellite were part of the Mesa Boogie product line. These amps were simpler companions to the Mark IV. Typically these were used as part of a stereo setup. (Mark IV effect-Send to stereo effect, 1 side of stereo effect to Mark IV effect-Re...
by SquierJVs
Fri Sep 09, 2016 7:22 pm
Forum: Express Series
Topic: Express 525 10" buzz even when no guitar connected
Replies: 7
Views: 2265

Re: Express 525 10" buzz even when no guitar connected

Hi alphasports, This sort of problem can be difficult to debug sometimes. Before taking it to a tech who is experienced with Mesa's, check for things like: - remove anything in the effects loop and/or try inserting & removing a plug in the return a few times. - check if the buzz is changing with the...
by SquierJVs
Wed Jul 13, 2016 9:20 pm
Forum: Mark Series
Topic: Mesa mk IV question about spax7 and suspicious screws
Replies: 3
Views: 1487

Re: Mesa mk IV question about spax7 and suspicious screws

Regarding the chassis screw, can you cut & paste the answer from the Mesa Boogie email? Now to the SPAX7 ... with this latest series of pictures, I definitely understand the problem better. The portion of the metal shield shown, is the base of the tube shield. In my Mark IVa, the base is fastened to...
by SquierJVs
Tue Jul 12, 2016 9:58 pm
Forum: Mark Series
Topic: Mesa mk IV question about spax7 and suspicious screws
Replies: 3
Views: 1487

Re: Mesa mk IV question about spax7 and suspicious screws

Hello, The rubber coating on the SPAX7 is a standard feature of this tube. And it is the recommended tube for the V1 position of the Mark IV. So you should leave it intact. The metal tube shield is also a standard feature for the V1 position and should be installed (assuming that you wish to use the...
by SquierJVs
Tue Jan 12, 2016 10:18 pm
Forum: Express Series
Topic: Mesa Boogie Amp Ringing/Whistling Problem
Replies: 5
Views: 1281

Re: Mesa Boogie Amp Ringing/Whistling Problem

Hello, The "screw" is really a narrow diameter bolt with a slot head. As others have noted, the bolt is intended to add tension the large, flat, horizontal panel of the chassis and reduce its vibrations. The extra length seems to be intentional as well. If you over-tighten the bolt, it will push thr...
by SquierJVs
Tue Jul 28, 2015 8:56 pm
Forum: Vintage Amps (Before 1991)
Topic: Mark IV - some questions
Replies: 5
Views: 2060

Re: Mark IV - some questions

As others have said, you don't have to remove the chassis to change tubes. A few tips: - the power tubes are easy to get at and change (I like my fingertips; so I let the tubes cool off). - preamp tubes are harder to get at. Easier if you remove a power tube or two. Sometimes, the RCA plugs will blo...
by SquierJVs
Thu Jul 31, 2014 6:17 pm
Forum: Vintage Amps (Before 1991)
Topic: New Mark IV version A owner questions
Replies: 3
Views: 847

Re: New Mark IV version A owner questions

2) mystery jack I found the answer in the Mark IVa manual. I should have looked there before experimenting. The "Satellite" powered amp & speaker systems have a similar GEQ jack. By connecting the two via a cable, the GEQ on the Satellite is enabled whenever the GEQ on the Mark IVa is enabled. 3) fu...
by SquierJVs
Wed Jul 30, 2014 9:22 pm
Forum: Vintage Amps (Before 1991)
Topic: New Mark IV version A owner questions
Replies: 3
Views: 847

Re: New Mark IV version A owner questions

Congrats on the MkIVa. 1) Reverb Try reversing the reverb cables. On my amp, the thicker cable (grey on mine) is plugged in the RCA closer to the amp front and the thinner (white) is plugged into the RCA closer to the back. Also check the cables for continuity. BTW the tubes seem reversed (That's no...
by SquierJVs
Mon Jan 28, 2013 8:31 pm
Forum: Mark Series
Topic: Mark IV troubleshooting, popping, volume fluctuating
Replies: 4
Views: 852

Re: Mark IV troubleshooting, popping, volume fluctuating

Lots of things can cause the symptoms that you describe. Take it to a good tech to find which one is causing the problem. With my Mark IV, the push-pull pots had worn out (although they did not make scratchy noises when they were used). Once the first one was found, I had all of them double checked ...