Tuning a V5?

[jrcorp]

 

I've modded my V5 ... the speaker problem isn't the 10" speaker it's the too small open cabinet that functions as a megaphone ... I have had a C10Q in mine they really need to be really broken in to sound OK ... I also have had a Weber Sig 10 Ceramic in it, I think it does sound a bit better than the C10Q but my C10Q isn't really broken in, check this out: http://www.unclespot.com/C10Q.html I've totally changed the circuit and it's pretty decent now but still limited. I bypassed the op amp input stage, pretty much made the preamp like a simple Marshall-like circuit with a Framus mid-cut control. The tone control is the 'character/drive control' turned down it's Fender-ish scooped mids and cleaner, open it up and it's more Marshall like with lots of mids and has more distortion.

 

 

Cool tip about the speaker. I've read that before but I don't have a variac to use... I think I would be fine apart from that though. The Jensen I have sure could use a little more bass. I'm not sure if mine is broken in. It's a clear improvement over the stock speaker, but I don't think it's a good choice to even out the sound.

 

If you have any details about your modding that you'd like to share, that would be great. This is my first time nodding an amp and any ideas would be great. Thanks.

[rock_mumbles]

 

Cool tip about the speaker. I've read that before but I don't have a variac to use... I think I would be fine apart from that though. The Jensen I have sure could use a little more bass. I'm not sure if mine is broken in. It's a clear improvement over the stock speaker, but I don't think it's a good choice to even out the sound. If you have any details about your modding that you'd like to share, that would be great. This is my first time modding an amp and any ideas would be great. Thanks.

 

I don't use a variac to break in speakers I use a 9V AC wall wart (transformer) I picked up at Goodwill ... from an old Nintendo I think ...

 

A decent op amp front-end is fine, most current pedals are op amp based until you get into the expensive discrete ones, the issue I had with the stock amp was it sounded to me like the gain control was overdriving the op amp which was then overdriving the tubes.

 

I have close to zero understanding of op amps ... so follow Verne's op amp mods ... first off I'd turn on the amp and play it listening carefully taking the gain control through its range. Then open it up and make sure that caps are discharged, then cut out C21 the cap he shows removed from the op amp circuit, change C27 to the larger 390pf cap and jumper C25, then plug it in and try it again with the same settings and listen to the difference. It's a pain but do only one section of mods at a time, then if you have issues you can fix it easier. Then the next step is to replace the op amp, I'd cut the old one out desolder the pins and clean the vias (pcb solder holes/pads) at this step I'd usually install an 8-pin socket but you can just solder the new op amp into the pcb. Make sure you have it oriented correctly and don't over heat it with your soldering iron. Also use good solder. You will have a hard time removing components/ desoldering because all new pcbs are manufactured with lead-free solder, it's hard and doesn't melt very well. Heat up the joint add some good new 60/40 or 63/37 solder (not lead free) let the joint flow and then desolder etc.

 

Verne's preamp is biased to be really creamy!!!

One thing to be aware of the amp will need C2 installed or a proper tone control that has capacitors that function as (include) the coupling cap(s) in their circuit. The tone control Verne used does that.

 

If you jumper C2, or use the C2 via (pcb solder hole) on the plate and take that to the tone control you are sending high voltage from the pcb to the tone control circuit, use good wire and don't go poking around inside with the amp on ... if you do want to poke around use a 'chopstick' or wooden dowel , not a pencil etc.

 

I'll keep checking in ...

[jrcorp]

 

I don't use a variac to break in speakers I use a 9V AC wall wart (transformer) I picked up at Goodwill ... from an old Nintendo I think ... A decent op amp front-end is fine, most current pedals are op amp based until you get into the expensive discrete ones, the issue I had with the stock amp was it sounded to me like the gain control was overdriving the op amp which was then overdriving the tubes. I have close to zero understanding of op amps ... so follow Verne's op amp mods ... first off I'd turn on the amp and play it listening carefully taking the gain control through its range. Then open it up and make sure that caps are discharged, then cut out C21 the cap he shows removed from the op amp circuit, change C27 to the larger 390pf cap and jumper C25, then plug it in and try it again with the same settings and listen to the difference. It's a pain but do only one section of mods at a time, then if you have issues you can fix it easier. Then the next step is to replace the op amp, I'd cut the old one out desolder the pins and clean the vias (pcb solder holes/pads) at this step I'd usually install an 8-pin socket but you can just solder the new op amp into the pcb. Make sure you have it oriented correctly and don't over heat it with your soldering iron. Also use good solder. You will have a hard time removing components/ desoldering because all new pcbs are manufactured with lead-free solder, it's hard and doesn't melt very well. Heat up the joint add some good new 60/40 or 63/37 solder (not lead free) let the joint flow and then desolder etc. Verne's preamp is biased to be really creamy!!! One thing to be aware of the amp will need C2 installed or a proper tone control that has capacitors that function as (include) the coupling cap(s) in their circuit. The tone control Verne used does that. If you jumper C2, or use the C2 via (pcb solder hole) on the plate and take that to the tone control you are sending high voltage from the pcb to the tone control circuit, use good wire and don't go poking around inside with the amp on ... if you do want to poke around use a 'chopstick' or wooden dowel , not a pencil etc. I'll keep checking in ...

 

 

Thanks for the advice. The tip about trying things out after each few steps is especially helpful. I have yet to work at the circuit, but I pulled the chassis out to measure for a head cab. I sketched out a scale drawing and I'm hoping to go to a hardware store tonight or tomorrow. I have a few days off, so hopefully I get a lot done. I also printed out the schematic for the V5 as well as Verne's so I can try to understand them better and use them for reference.

 

I have no experience working with wood, so any advice there would be good too. Using a few resources online to help, I'm planning for a 3/4" pine cab, constructed with butt ends, glued and either screwed or nailed together. I'll probably have the store cut the wood for me, as it'll save me a little work doing it well. The cab will leave a space beneath the chassis and transformers about the same height as the tallest transformer, and will end up about half the size of the combo. There will be a lot of details to work out, but if I take my time I think I'll be okay. My main concern now is routing the corners with room to put the wood together, or vice versa. I'm guessing I'll route 1/4" curve to make it easier.

 

Also, if the speaker mod/break-in is as easy as hacking up a wall wart, I'll have to try that soon too.

[rock_mumbles]

 

... Also, if the speaker mod/break-in is as easy as hacking up a wall wart, I'll have to try that soon too.

 

 

It has to be an AC (output) wall wart, not DC. DC will fry the speaker.

[jrcorp]

Update! Yesterday I managed all of the mods on the V5 that I had adapted from Verne's work. I was a little uncertain of some of the component values as I'm not experienced and was making half-educated guesses, but everything seems to have worked out well. I even added in a capacitor present in the V8 not included in the V5's circuit.

 

The results are great. First of all, I can crank the volume fully without any unpleasant noise that I wouldn't expect. There's a lot more low end that sounds great; actually, I think the low E might sound a little flabby now. I had a blast playing around with humbuckers, and I strung up my Tele last night so I'll fool around with that shortly. I was so excited to fire it up and even more to turn it up fully and get some beautiful distortion. I feel like the distortion sounds pretty compressed... from what I've read and heard this is the natural sound of tubes but I wonder if it could be helped a bit. Either way, huge thanks to Verne for all his time and effort that went into his schematics and mods.

 

Next up, I would love to work in a legitimate tone control. I'll probably copy Verne again, but I'm curious what my options are. I might run to the store and grab supplies to start on the head cabinet, and I have a speaker on the way. Though I may try the speaker break-in for more low end later on, I like what I'm hearing so far after working on the circuit. Hopefully I get my act together and record something to show how far the amp has come, and maybe I'll take pictures of the "after."

[jrcorp]

Installed the Alnico speaker, and I have mixed feelings about it. There seems to be an improvement in mids and a smoothness that I don't get with ceramic, but there's a loss of crispness and brightness. I'm not much of a tone connoisseur, so it's tough to put in words. I might switch back and forth a few times, and I have another 1x10" combo to try the speakers in too.

 

Still have yet to make a parts order, and recording will wait too because my computer's on the fritz.