The Amp Garage

I have the BPSSC on my main Strat with Lindy Fralin single coils. Sounds great!! I have a no load tone pot that is the one that disconnects itself from the circuit when fully clockwise to get the "brightest" sound possible out of these pickups. When you rotate it away from "10" it adds the tone cap ...

Here's a picture of my Gepco snake for my rig after about 5 years of hard use. The jacked has tightened around the internal cables and then twisted. I very carefully figure 8 ALL of my cables and the Gebco cable is what you see. Some of my other Canare cables I have are 15 years old and going strong...

Just wanted to confirm if anybody knows the truth to the tap percentage on Fender 70's UL amps. I always assumed they were at 43% which is the normal value for audiophile usage. Is it true that they were at 20%? (which gives the most power in UL mode but negates the lower distortion specs which UL i...

Thanks for the UL info on my project ...... I will try it here soon. One more question is biasing now in UL mode. I've been biasing to 70% of 25 watts. At 420volts that would be around 40ma per tube (I actually have separate bias controls for each tube). Does this all change since it is capable of m...

I'm using a 1650K in a EL34 PP amp and have always wondered what UL sounded like...especially for a hyper clean sound. My PT is only putting out 420V after SS rectification and 1st filter cap. Is that a safe voltage to use in UL mode? Do I just need to move the screen connection from choke output ov...

Since your son is drop-D tuning do what Diezel does to really "tighten" up the output section. 10k FB on 8Ω. Absolutely wonderful IMHO. This goes against what a lot of guys post here but it works well if he's using high gain settings and wants the low stuff to articulate and not mush out. You'l...

Included is a pict of the V2 and V3 gain stages in a recto. I know on V3 the cap across the plate resistor is to dump high end (snubber). What is the cap on V2 doing. Is it placed close to the tube to increase high end transients on that stage or something else? Technically it's in the same node as ...

Never mind ...... I see it now. The 4meg tied across the inputs is a really a non-path as the two inputs are directly connected to each other thru the linked jack. I see now that V.1 ends up being 500k input resistance when linked input is used; and in V.2 the 1meg input resistance is maintained usi...

Thanks Kagliostro and tubeswell for the additional info. I've included the 2 schematics off of the HiWatt site. In version 1 the Linked input feeds each of the 68k input resistors which each have their individual 1meg grounding resistors. Normal Y configuration. In version two, 2meg grounding resist...

For what it's worth .... my last Hammond transformer was a 291FX which is the upgraded Twin transformer. The pdf sheet on their site says 640v secondary at 518ma, got the tranny and it says 670v and 450ma on the label. After SS rectifier I got a whole 410v out of it at idle in the twin circuit. Bumm...

I used to own one of the great super gain amps of all time .... the DIEZEL VH4S (stereo). Looking under the hood I noticed that Peter uses a single preamp DC node. The output plates are on their own node, then the screens are on their own node, and then there is a single node to supply the PI’s (2) ...

On my design chassis I have two totally independent preamps that I would like to experiment using together at the same time. One has two gain stages and the other four so they are in phase. What’s the consensus out there on paralleling the inputs together? I know a lot of players of say two channel ...

Thanks man. I'm also interested to see how filtered/stiff you had the PS in the preamp sections. Just curious! Thanks again.

I worked from this schematic made by DBM: [IMG:800:566]http://i46.photobucket.com/albums/f112/gldtp99/Laney%2050%20AFD%20Mod/AFD-DBM.gif[/img] The amp started life as a Laney AOR 50 made in 1987--- i gutted the PCB and built a 50 watt (turret board) version of a Krankenstein from the schematic onli...

Has anyone done any research per the quality of cathode bypass caps in the circuit? It's very apparent that resistor quality/type affects noise down line in audio signal path parts of a circuit as well as coupling cap quality/type affects tone. Are cathode caps and associated resistors actually in t...