The Amp Garage

Another way to increase even (harmonious) harmonics is to use 68K to 82K plate load resistors. I have done it on several builds and it does sweeten up the sound. It does decrease stage voltage gain relative to the typical 100K-220K load, but I am assuming you have multiple gain stages and are using ...

Another option is to go high velocity pellet gun in .17 or .22 cal. I can shoot the wings of of a gnat at 100m with mine (not really, but heard Jed Clampett could) I have a lot of fun with mine and it relatively quiet for a 1000f/s. CB caps in a .22 rifle are very quiet, but that doesn't help if you...

+1 on Voodoo's advice. My builds have a centrally located #10 bolt long enough to accommodate all my grounds. I place a ring terminal on all ground wires and separate them with washers. I use a locknut to hold the bolt to chassis and then one locknut on top. Have had good results with Mr Blencowe's ...

Like the other guys suggested - if you want a specific feel, try something in the 0.47u to 22uF range. 22uF across a 1500 Ohm cathode resistor creates a low frequency corner at ~ 5 Hz. It's not likely that your guitar amp has flat response down to 5 Hz. For me personally, I'll plug in a value and th...

There are many grounds schemes out there. My last build used a 12guage copper wire for preamp/pots/input jack ground. That ground, together with output cathodes, speaker gnd, reservoir gnd caps, screen caps, and PT center taps are connected to a centrally located chassis bolt. I solder lugs to each ...

Here's a interesting senior project including analysis and suggested improvements for the Tweed Deluxe.

http://courses.physics.illinois.edu/phy ... Deluxe.pdf

I corrected a similar problem with a newer Marshall amp with an effects loop: one of the jacks was bad and would intermittently cause the amp to cut out because the unused effects loop was opening up. I verified it by running a patch cord from effects loop out to effects loop in.

rob

So it has to be before (viewing from where signal comes) the grid load resistor, 1M in case of typical 12AX7 input stage, so the grid stoppers are in before the cap? That's right. For a cathode bias input stage, input jack is connected to first grid through a coupling cap. Typical value 1M resistor...

Some guys add a fairly large (by speaker impedance standards) across the output transformed to protect amp in the event that it is played with no speaker attached. A 220 Ohm power resistor soldered across speaker outs won't shunt significant current from speaker.

rob

I made probes for my scope from small diameter coax, bnc connector and two EZ hooks. You don''t really need an expensive probe. Bandwidth on a guitar amp is ~10kHz. If you'd rather use a manufactured probe, they are cheap on ebay. Be sure you order a RoHS probe, cuz we all know how insanely toxic ti...

Adjusting the reservoir cap will have the most effect on your sound. Increasing the screen filter cap size will give you a more stable B+2, but that could affect your sound. IMO, increasing the three preamp capacitors will only improve things - it would keep the power tube current draw from modulati...

Original screamer - how about this deal? I bought the same unit from Ray Henning's Heart of Texas music in Austin when I was in college in '81. It was $25. http://www.ebay.com/itm/1981-VINTAGE-IBANEZ-TS-808-TUBE-SCREAMER-OVERDRIVE-PRO-w-RARE-TI-RC4558P-CHIP-/290852453060?pt=Guitar_Accessories&hash=i...

Reeltarded wrote:Dood, my teeny terror mods are awesome. Grrrr..

Reel,

Have you posted them on the Tiny Terror Mods sub-forum?

rob

Don't mean to cast aspersions, but isn't using these BFTs - some how, some way - an attempt to compensate for some other shortcoming? [Freud mode = off]



rob

Agree with chief: Merlin's ground scheme works very well. Hoffman has a good scheme too - his basically busses all the preamp grounds into a single point (transformer bolt) where filter, output cathodes and other grounds are tied.

I have used both and had good results.


rob