Search found 153 matches

by Henz
Fri Oct 09, 2020 11:06 am
Forum: Vintage Amps (Before 1991)
Topic: Weird.
Replies: 0
Views: 193

Weird.

Ok, the other day I was playing my DRG C+. It sounded ok. Occasionally, with amp on, I'll unplug input and get a pencil and very gently tap on preamp tubes to check for microphonics and other noises. I also turned all of the front knobs just to loosen things up. Put settings back exactly where they ...
by Henz
Wed Jul 29, 2020 10:57 am
Forum: Rack Pieces
Topic: Stereo 2:90 Versions differences
Replies: 3
Views: 299

Re: Stereo 2:90 Versions differences

Hello. I've had the opportunity to only try version one, which I've owned since the mid 90's. I don't have a triaxis tho. I slave my C+ to it. No, it's never been noisy. Of course if you crank up the levels all of the way, with no input, you will hear a very slight hiss. And of course certain power ...
by Henz
Sat May 09, 2020 6:07 pm
Forum: Mark Series
Topic: Mesa Boogie MK2C+ EQ Transistor question?
Replies: 9
Views: 2736

Re: Mesa Boogie MK2C+ EQ Transistor question?

Thanks for the schematic. A short while ago I had a chat with Mike B. about my C+ DRG. I was asking him why my amp still had C21 , 1000pf, and C10 was a 10 pf while the schematics said otherwise. He told me that those caps are a bright reduction mod in earlier C+'s. Mine still has C25, 500pf, but di...
by Henz
Sat May 09, 2020 12:31 pm
Forum: Mark Series
Topic: Mesa Boogie MK2C+ EQ Transistor question?
Replies: 9
Views: 2736

Re: Mesa Boogie MK2C+ EQ Transistor question?

Thanks for the reply and info and link! I'll give it a good once over! :) Blessings, Jim
by Henz
Sat May 09, 2020 12:26 pm
Forum: Vintage Amps (Before 1991)
Topic: Orange drops
Replies: 3
Views: 1349

Re: Orange drops

Thanks for the reply. Thanks for the link. It is interesting. The video that I watched on that very well known site, the tech tested them the same way with an o scope. But still, that link does ,in most part, does say that they need to be installed a certain way in amps. So yes, I do agree with you....
by Henz
Sun May 03, 2020 2:50 pm
Forum: Vintage Amps (Before 1991)
Topic: Master One pot value
Replies: 2
Views: 1192

Master One pot value

Sorry for flaming. But I need input. I have a factory C+ DRG . Mike B. repaired it a while back. He replaced some pots. He put a 250k pot in the Master One. Some schematics says a 1meg. What's the difference and what should I go with. Thanks for your time.
by Henz
Sun May 03, 2020 2:22 pm
Forum: Vintage Amps (Before 1991)
Topic: Orange drops
Replies: 3
Views: 1349

Orange drops

Hello. I recently seen a video about Orange drop caps. How the foil end (the black band mark, Mallory's have them but not Sprague s) should be installed in amps . When going down the assembly line, it's not sure , when inked, that the banded side is correctly marked. The tech in this video used an o...
by Henz
Thu Apr 23, 2020 12:12 pm
Forum: Rack Pieces
Topic: fix blown 50/50 amp
Replies: 12
Views: 2153

Re: fix blown 50/50 amp

Another quick way to determine if it is a bias issue ( resistor hopefully) is to check the socket while amp is on stand by. But please, there is dangerous voltages inside. If you choose this, be very careful and take your time. Get your volt meter, put it on DC . Take the red probe and attach it to ...
by Henz
Thu Apr 23, 2020 10:52 am
Forum: Rack Pieces
Topic: fix blown 50/50 amp
Replies: 12
Views: 2153

Re: fix blown 50/50 amp

Sure. I'll try. Locate socket inside amp. The screen grid resistor will be very close to the lead wire from pin 3 on socket. 470 ohm. It will, or most likely be, a large ,brown carbon composition resistor 2 watt.( yellow, purple, brown color bands). From there, nearby, off of pin 5, there will be a ...
by Henz
Sat Apr 18, 2020 1:27 pm
Forum: Mark Series
Topic: Mesa Boogie MK2C+ EQ Transistor question?
Replies: 9
Views: 2736

Re: Mesa Boogie MK2C+ EQ Transistor question?

I forgot to mention something that kinda bothers me. Why didn't Mike and Doug build all of the C+'s the same? I've seen picts of Mallory's in the tone stack, some Sprague. All throughout amps. I remember reading Boogie Babies saying that no two C+'s sound the same due to this. That bothers me. Let's...
by Henz
Sat Apr 18, 2020 1:07 pm
Forum: Mark Series
Topic: Mesa Boogie MK2C+ EQ Transistor question?
Replies: 9
Views: 2736

Re: Mesa Boogie MK2C+ EQ Transistor question?

Nice to hear from ya! I may have been a bit hasty when saying a few inconsistencies. I just now looked at the Slocone version and saw in lower right that it is for a C+ DSN. Not sure what s n means. Anyway ,the D is for Simul Class and in my SC, there's a diode on pin 3 of inner sockets going to gro...
by Henz
Mon Mar 30, 2020 9:34 am
Forum: Rack Pieces
Topic: fix blown 50/50 amp
Replies: 12
Views: 2153

Re: fix blown 50/50 amp

Try to locate and measure bias resistor . Pin 5 . 220k (red,red,yellow bands). Screen grid resistor as well 470 ohm (yellow,purple,brown) . If it's just one socket, that's what I would do. Maybe .1 coupling cap to that socket (Orange drop).It also would have been good to put two new bias caps in (47...
by Henz
Fri Mar 13, 2020 12:41 pm
Forum: Mark Series
Topic: Mesa Boogie MK2C+ EQ Transistor question?
Replies: 9
Views: 2736

Re: Mesa Boogie MK2C+ EQ Transistor question?

Here's another one. But as I mentioned , there are a few errors when I traced my C + with it. Between this one and Slocones, there are some inconsistencies. Slocones PI circuit is pretty accurate. https://drive.google.com/file/d/1ieTnML ... LAcUQ/view
by Henz
Mon Mar 09, 2020 5:46 pm
Forum: Rack Pieces
Topic: fix blown 50/50 amp
Replies: 12
Views: 2153

Re: fix blown 50/50 amp

Greetings WoodButcher, I'm glad I caught you here. This is off topic but I need your advice. I repaired my 26 yr old 2:90. First,let me itemize what I did. Hard wired PT leads directly to PCB,replaced two Orange drops (C16, C20),replaced cracked 2.7k 2 watt carbon comp resistor with a wirewound (res...
by Henz
Fri Mar 06, 2020 6:42 pm
Forum: Vintage Amps (Before 1991)
Topic: Foam in verb?
Replies: 0
Views: 3555

Foam in verb?

Hello, so I was reading some older posts and read one about MB going over an amp and servicing it. He posts what Mike did to his amp. One that I'm wondering about is that Mike replaced the deteriorating foam inside verb tank. Does anyone know what function that foam does? Why is because I recently p...