Search found 305 matches

by novosibir
Tue Jan 01, 2013 2:48 am
Forum: Technical Discussion
Topic: Lar/Mar PPIMV
Replies: 67
Views: 13299

Re: Lar/Mar PPIMV

Reeltarded wrote:Larry! Happy New Year, buddy!!!
Thank you!

Happy New Year 2013 to all of you out there!
Wherever you are on this planet!

Larry
by novosibir
Mon Dec 31, 2012 5:15 pm
Forum: Technical Discussion
Topic: Lar/Mar PPIMV
Replies: 67
Views: 13299

Re: Lar/Mar PPIMV

Is there some reason that the shielding is connected to the bias voltage? Would it be as effective or even more so if it were attached to ground? I ask because after installing it on an express build I'm getting what is obviously feedback or low frequency (~300Hz) parasitic oscillation when the Mas...
by novosibir
Mon Dec 31, 2012 5:07 pm
Forum: Technical Discussion
Topic: Lar/Mar PPIMV
Replies: 67
Views: 13299

Re: Lar/Mar PPIMV

Using the shield to carry the bias voltage is an interesting idea that was not part of the original design. Off-hand I can't see a problem with that. Usually I don't use shielded wires by putting in a PPIMV into an amp, I just twist the cables and additional I'm running the twisted bundles close to...
by novosibir
Mon Dec 31, 2012 5:00 pm
Forum: Technical Discussion
Topic: Lar/Mar PPIMV
Replies: 67
Views: 13299

Re: Lar/Mar PPIMV

It's the same when it's turned all the way up, but as you lower the volume the resistance to ground will increase, which will change the load on the PI. Thanks Martin. I think I will try it both ways and listen for the difference... dual 250Ks are delayed in transit. Martin is right and it's worth ...
by novosibir
Sat Oct 02, 2010 7:52 pm
Forum: Technical Discussion
Topic: AO 35 into Spitfire master volume issue
Replies: 16
Views: 4704

Re: AO 35 into Spitfire master volume issue

A loud YUPP to the post beyond! Give me a pen, so that I can sign it 8) But... @ Gaz! When your Lar/Mar PPIMV in a marshall-esque fixed bias amp sounded like crap, then there's been either something wrong? Some simply forget to remove the cables from the coupling caps to the output grids :wink: Or y...
by novosibir
Mon Jan 26, 2009 11:47 pm
Forum: Dumble Discussion
Topic: Dumble wrote a chapter for TUT6!?
Replies: 13
Views: 1791

Re: Chapter 6

A noteworthy exception is Dave Funk's book, which was probably from around that time as well. I still have it and I've always had the impression that Dave knows very well what he talks about. So Dave, if you're reading this, hats off to you, my friend. Too bad you never published part 2 of your wor...
by novosibir
Tue Jan 13, 2009 6:54 pm
Forum: Technical Discussion
Topic: 1meg vol. pot vs 500K ?
Replies: 6
Views: 2566

Re: 1meg vol. pot vs 500K ?

tubedogsmith wrote:If you use the 500k pots run a 470k resistor off the wiper. It will slow down the taper a bit but will work fine, you may even like it better.
... and makes the input of the next stage highly sensitive for catching all kind of noise!

Not a good idea IMO!

Larry
by novosibir
Tue Jan 13, 2009 6:49 pm
Forum: Technical Discussion
Topic: Soldering the Unsolderable
Replies: 6
Views: 1521

Re: Soldering the Unsolderable

Dimp the contacts into silver cleaner fluid for a few seconds and then wipe it off w/ a paper towel. Sanding removes the galvanic coating and the basic metal doesn't solder very well.

Larry
by novosibir
Sat Jan 10, 2009 5:04 am
Forum: Dumble Discussion
Topic: 70w Fender OT
Replies: 12
Views: 1015

Re: 70w Fender OT

the prim. impedance is 8k8 , so I could use the 16 ohm tap with my 8 ohm Altec for 4k4.I wonder if anyone of you has experience with this model. Just seen your post. No prob to use the OT w/ 2*6L6 as a 4.4K prim w/ 8 ohms load on the 16 ohms secondary, but it might be, that it saturates earlier as ...
by novosibir
Mon Jan 05, 2009 10:46 pm
Forum: Dumble Discussion
Topic: D'lite 6L6 build: Bright!
Replies: 45
Views: 3763

Re: D'lite 6L6 build: Bright!

Wow that amp must have had a lot of brightness hitting the OD to warrant 390pf snubbers. I went step by step, first raised to 330p both - still brittle. Then 360p both, but still too brittle. Raised only the OD1 to 390p, but not enough - hence both now 390p. After this I've still heared some slight...
by novosibir
Mon Jan 05, 2009 9:47 pm
Forum: Technical Discussion
Topic: mesa inverter bias
Replies: 3
Views: 1192

Re: mesa inverter bias

Wayne wrote:More headroom, maybe?
Exactly!

It's the same advantage as a for the same voltage enhanced supply voltage to the PI's plate R's - but an enhanced supply voltage not always is a benefit tonewise.

Larry
by novosibir
Mon Jan 05, 2009 9:18 pm
Forum: Dumble Discussion
Topic: D'lite 6L6 build: Bright!
Replies: 45
Views: 3763

Re: D'lite 6L6 build: Bright!

Last summer I've refined a Ceriatone for a buddy. Besides other minor tweaks I've put in a slightly lo-cut to the OD section, an additional .022 after the relay to the OD's entrance (with a 4.7M pop suppressing R to ground at the relay's side), to tame the amp's boomyness. But I couldn't get rid of ...
by novosibir
Sun Jan 04, 2009 1:33 pm
Forum: Garage Talk
Topic: I'm broke but you may not be
Replies: 11
Views: 2078

Re: I'm broke but you may not be

gahult wrote:That's the F-14.
Yesss! This one I've meant! Thanks Gary!

Larry
by novosibir
Sun Jan 04, 2009 12:35 am
Forum: Garage Talk
Topic: I'm broke but you may not be
Replies: 11
Views: 2078

Re: I'm broke but you may not be

Aurora wrote:
novosibir wrote:Looks like a F16 from behind :?

Larry
F16 is single blaster..... :D
Ой блин! I'm not an expert concerning military stuff! I've meant the bird, Michael J. Fox was flying in that one film. Was it Top Gun? Was it a F18? A MIG29?

Larry
by novosibir
Fri Jan 02, 2009 12:51 am
Forum: Garage Talk
Topic: I'm broke but you may not be
Replies: 11
Views: 2078

Re: I'm broke but you may not be

Looks like a F16 from behind :?

Larry