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Here is a schematic of the modification I discussed above, it's similar to Deafelectromark's mod except I wanted to re-voice the preamp, replace the tone control with a mid-cut tone control and instead of cutting the traces to the volume pot I pulled it from the pcb (be careful if you aren't...

It's completed, to tame the highs a bit I ended up putting a 680pf cap across R6, that did the trick. I pulled the Weber Ceramic Sig 10 (smooth cone) and replaced it with a new Jensen C10Q I picked up for $20 ... I decided I wanted to keep the Weber Sig 10, it sounded a lot better in the Crate...

I used a 240 ohm cathode resistor and wish it was still a bit smaller, although I do have a 100 ohm (not-a) sag resistor that drops a few volts. My plate voltage is now 297V and the screen is 289V, prior to reworking the dropping resistor and screen resistor the screen was about 310V and the...

What I did on my CV 50's Tele was I added a ground wire to the neck pickup cavity ... it was painted with shielding paint but it wasn't connected to the control area shield ... so I took a couple of short small screws and added a wire to connect the front cavity to the control cavity.

My brother and I each have modded V5's and I've modded two for a friend. As far as I'm concerned a simple tube swap or speaker swap will help, but it won't fix the problem. The V5 does not have a volume control, it has a op-amp gain control, and as you have experienced it's OK at low volumes...

Check for continuity I don't have a V5 to look at (it's loaned out), but before you tear out C24 again, looking at the top traces you can see, where do they connect, one end of C24 connects to the op-amp pin 1, to one side of C26 and to one side of R12. The other side of C24 connects to R14...

Standard Tube Amp High Voltage Warning ... there is in excess of 300V inside the chassis!!! I wouldn't use "only" solder to repair a pcb trace, I'd solder a wire to complete the circuit. C24 is a signal cap, in the op-amp circuitry, without it "carrying signal" there will be no...

RE: post #278 :: Split Resistor Treble Boost Hi Jim, I just did this on my "Home Bake" (5F1 ???) scratch built amp and I really like it. I previously had a 1.5K cathode resistor bypassed with a 2uf film capacitor. With the split resistor treble boost the tone was evened out, it helped to...

You could make any of them work... (my opinion) The third one would probably be the easiest to fit into the PCB I would expect it to be the smallest of the three caps and it has radial leads. The second and third are probably both higher quality caps than the third one but installing them...

I use wire from a burned out computer power supply to connect volume or tone pots and for runs of a few inches on a circuit board. A friend bought a professionally modded amplifier and all of the jumpering was done with single conductor stranded wire. In my V5 I jumped around the OP-amp with a...

Conjunctive Filter question ... Hi Jim, since you know and really understand this stuff and I'm just a hack ... I read a post on sewatt.com about using a conjunctive filter to keep the grid at the proper voltage in reference to the plate voltage. Can you explain this a bit more??? Thanks!

Conjunctive Filter Hi Jim, I have put Conjunctive Filters (CF's) on two amps. I've used a 1nf capacitor on one amp and a 2.2nf capacitor on the other, the 2.2nf is used by a high end amp builder. You just want the CF to take out some of the EL84 harshness without changing the overall sound...

Valve Junior vs Crate V5 (long winded...) I'll chime in on this one... IMO a modded V5 is probably a better bedroom amp as it's not quite as loud and has a cabinet designed for a 10" speaker, a miked up modded Valve Junior head with a decent cabinet is a usable moderate volume stage amp...

Should I (could I) add another filter cap? Hi Jim, Would it help to add a 22uf 450V filter cap (to ground) in the B+ supply where R18 was connected to J4? I just happen to have several caps without amp "homes". Thanks

Like Scihibmxer posted, unfortunately the Crate V5 is not as easy to mod as some other amps I've modded in the last year, you won't gain much by just changing out a resistor or cap like other amps. We both thought - a nice little combo amp for a decent price, only 5 watts so it won't make quite...

Yes that is the volume/tone control I used. I got the amp working like I want it today, I put a 150K resistor between C2 and the volume pot and a 470K from the volume pot side of the 150K to ground (effectively have a 250K volume pot). Now the amp works fine! BTW, I have removed C3. Now I...

Thanks for the info about C3 and R16 in post #111. I now have a blue eminence alnico 1028 speaker in my amp, and it's probably not really the amount of high end that bothers me it's the level of overdrive. I have bypassed the op amp and have replaced C2 with a 0.022uf 715 Orange Drop which...

C3 and placement of R16 Hello guys, A couple of things, I've modded 3 Valve Juniors (all different) I like the sound of all three, the V5 has a lot more high end (too much to my ears) and also has a bit more gain than I'd like. So, can anyone tell me what the purpose of C3 is? It's the...

Hi Jim, first thanks for all the modding info ... I think that the above statement was addressed to me. With the V5 I played with yesterday, the 10" ceramic sig in the V5 cabinet sounded more "megaphone" like (boxy - unnatural midrange from too small of a cabinet) than the alnico 8" sig that...

Crate v5 speaker A friend has an all tube (modded) V5 with a Weber Sig 10 ceramic in it, it sounds a whole lot better than the stock speaker, but today just for grins I hooked up his custom made harp amp cabinet with a Weber sig 8S alnico, it sounded a lot less "boxy" than the crate v5 with the...