Search found 104 matches

by darkbluemurder
Fri May 04, 2018 10:17 am
Forum: Vintage Amps (Before 1991)
Topic: Speaker recommendations
Replies: 4
Views: 1926

Re: Speaker recommendations

If you can get one the Eminence MOD 12 is a great speaker for the small combo cab. If you want something lighter weight, Jensen Neo Tornado, the 100 watt version.

Cheers Stephan
by darkbluemurder
Fri May 04, 2018 10:10 am
Forum: Mark Series
Topic: How to mod mark III blue stripe to III++?
Replies: 12
Views: 4047

Re: How to mod mark III blue stripe to III++?

Many thanks Jon for sharing all this.

cheers Stephan
by darkbluemurder
Wed Mar 21, 2018 1:11 pm
Forum: Mark Series
Topic: '81 Mark IIB Troubleshooting - blowing fuses
Replies: 10
Views: 4769

Re: '81 Mark IIB Troubleshooting - blowing fuses

The diodes appear to be OK. Next things to check would be the filter caps in the power supply for shorts as already mentioned. In order to check the power transformer you have to disconnect any secondary wires from the circuit, tape them so that they cannot short against anything, put in a new fuse ...
by darkbluemurder
Thu Mar 08, 2018 4:48 am
Forum: Mark Series
Topic: Mark III to Mark II mod
Replies: 74
Views: 23295

Re: Mark III to Mark II mod

Fwiw a lot of folks out there are misinformed about what Mark series amps can be modified to a C+ and which can't (and why). From what I have read the IICs can be upgraded to a IIC+, which is what MB have offered as a factory upgrade. I also know that the first Mark IIIs (no stripe/dot/black stripe...
by darkbluemurder
Mon Mar 05, 2018 8:22 am
Forum: Off Topic
Topic: Post No. 100
Replies: 0
Views: 1204

Post No. 100

Thanks for this forum and thanks for having me here.

Cheers Stephan
by darkbluemurder
Mon Mar 05, 2018 8:21 am
Forum: Foot Pedals & Misc Mesa Stuff
Topic: Flux Drive Review
Replies: 1
Views: 2189

Flux Drive Review

I will review the pedal in the context of the manufacturer's description and the way I tested it (standalone before clean amp, push a driven amp and clean boost after overdrive). This is how Mesa Engineering describes the pedal: The FLUX-DRIVE™ is the overdrive pedal for those who want more of all t...
by darkbluemurder
Mon Mar 05, 2018 8:05 am
Forum: Mark Series
Topic: Mark III to Mark II mod
Replies: 74
Views: 23295

Re: Mark III to Mark II mod

Can't be done. Most notably because the IIC(+) and Mk-III have different pre-amp circuit boards. Never mind the PT etc.... I guess you meant by "can't be done" "can't be done exactly", and if so, I agree. Different circuit boards have different stray capacitances. I also agree that power transforme...
by darkbluemurder
Mon Mar 05, 2018 7:59 am
Forum: Mark Series
Topic: Electrolytic Caps
Replies: 5
Views: 1863

Re: Electrolytic Caps

The smaller electrolytics are mostly in parallel to the cathode resistors on the preamp stages. They increase gain. Unless they are faulty you will probably not notice much of a difference between one electrolytic and another.

Cheers Stephan
by darkbluemurder
Tue Feb 27, 2018 5:59 am
Forum: Mark Series
Topic: Mark III to Mark II mod
Replies: 74
Views: 23295

Re: Mark III to Mark II mod

Here is what I did to my purple stripe: 1. Change C30 from 0.002uf to 0.001uf. 2. Change C516 from 0.01uf to 0.0047uf (this cap is in the feedback circuit in the output section) Check whether the output of the lead circuit has the 220k II 250pf to 100k II 500pf voltage divider. My amp had it but the...
by darkbluemurder
Tue Feb 27, 2018 5:43 am
Forum: Vintage Amps (Before 1991)
Topic: Mark IIC+ 60 Watt
Replies: 16
Views: 10795

Re: Mark IIC+ 60 Watt

That purple headshell rocks.
by darkbluemurder
Fri Feb 23, 2018 4:24 am
Forum: Mark Series
Topic: Mark III schematic
Replies: 15
Views: 6773

Re: Mark III schematic

Hi Jon,

Thanks for your great work. Can you please upload one schematic as standard pdf-file? I have difficulties downloading it.

Thanks,
Stephan
by darkbluemurder
Fri Feb 23, 2018 4:09 am
Forum: Mark Series
Topic: Updated Mark III+ Info
Replies: 23
Views: 8291

Re: Updated Mark III+ Info

One big myth is that the Blue Stripe is the same as the Red stripe minus the C30 mod. There are lots of component values that were changed between them. The Green and Blue stripes also have a different resistor alongside the C27 capacitor that is supposed to have as much if not more of an effect th...
by darkbluemurder
Thu Feb 15, 2018 5:56 am
Forum: Vintage Amps (Before 1991)
Topic: MarkIII Blue stripe overdrives.
Replies: 2
Views: 1388

Re: MarkIII Blue stripe overdrives.

Given that the Mark amps are Fender based they are an excellent pedal platform. One of my favorite drives with them or any other clean amp is the Barber Direct Drive (any variant of it).

Cheers Stephan
by darkbluemurder
Wed Feb 14, 2018 4:16 am
Forum: Vintage Amps (Before 1991)
Topic: The best substitutes of MESA STR-415 & 416
Replies: 11
Views: 6019

Re: The best substitutes of MESA STR-415 & 416

GJgo wrote:When I asked Mike B. for my 105 PT he recommended the TAD 6L6GC-STR as one that can take the voltage. If you read up on it it's loosely designed after the old 415.
I used those when I retubed my Mk III a few weeks ago. Too early to comment on the reliability but no problems so far.

Cheers Stephan
by darkbluemurder
Wed Feb 14, 2018 4:14 am
Forum: Mark Series
Topic: Mark III schematic
Replies: 15
Views: 6773

Re: Mark III schematic

Jon, Many thanks for sharing! The lead circuit is quite similar to my purple stripe 60 Watt, except that - the resistor in parallel with the lead drive pot is 470k instead of 150k, which would provide for a bit more bass at higher settings. I think the 150k is actually beneficial as it tames bass be...