Crate V5 mods... anyone?

[jim p]

RE plate power dissipation

It looks like the Weber calculator allows just 2mA for the screen maybe just being conservative. Going by the 11 volts on the cathode if you had a 270 ohm resistor and the voltage stays at 11 volts your cathode current would be 41ma so would be just about bang on 12 watts on the plate ( 319 volts times 38mA = 12.1 watts)

 

[rjohnj]

It looks like the Weber calculator allows just 2mA for the screen maybe just being conservative. Going by the 11 volts on the cathode if you had a 270 ohm resistor and the voltage stays at 11 volts your cathode current would be 41ma so would be just about bang on 12 watts on the plate ( 319 volts times 38mA = 12.1 watts)

yeah that's pretty much what I got just pushing the boundaries slightly with 250 ohms to help with the sound a little.
Not sure why I have to run it so hot to get rid of the 'farting' though. 100ohm resistor sounded good but just ran the tube too hot.

 

[SciHi]

...get rid of the 'farting' ...

I have found that the v1a cathode bypass cap and/or first coupling cap control the flabby bass. For HBs I have used either 0.68 or 1 uF cathode bypass caps, you can go a little higher with single coils, ~2uF. Or use a real small coupling cap, like the vj fender/voxy mod value, 0.0022uF, my v5 has a 0.0047uF coupling cap. I am using 10K R1, added a master volume with 6.8K grid resistor after the mv, and did the screen resistor mod to the el84. My tone stack sucks lots of gain so the amp is very clean and very tight bass but still retains the thick tone. I also tried adding the nfb but it was too thin with my setup. My speaker is also a thick cone Celestion Tube 10 (G10E-30), and doesn't breakup even playing a bass through the amp. I suggest you try to figure out if it is the amp or speaker that is causing the "farting."

Rock_Mumbles posted this on his tech site "zaphod_phil Quote:
I think the moral of the story is to either use a smallish cathode cap (below 100uF) and bias fairly hot with a low cathode resistor value, or use a very large cathode cap (1000uF to 2200uF) and bias cooler with a larger resistor value. In between values will usually sound woofy."

found here:
http://www.18watt.com/modules.php?n...pic&t=17468&postdays=0&postorder=asc&start=15

So maybe as you change the el84 cathode resistor value, you need to change the cap value?

 

[jim p]

output tube bypass cap value?

One thing to keep in mind as you lower the value of coupling caps and bypass caps you are reducing the bass response. So you may just be eliminating the problem by having less bass, ok if the bass response is not important to you. One thing to search out on the web for is blocking distortion you do reduce this by reducing the value of coupling caps but you can also reduce the value of the grid resistor on the control grid of the tube to reduce it.
When you bias hot by reducing the cathode resistor value what may be the reason for better response is the RC time constant (resistance times capacitance) of the cathode bypass capacitor and cathode resistor is reduced. The cathode of the output tube shifts its DC value when driven hard and the recovery time could be a function of the bypass capacitor used. So instead of biasing the tube hot maybe you should try changing C9 to a lower value by calculation you could go as low as 10uf with a cathode resistor value of 270 ohms.

 

[rjohnj]

One thing to keep in mind as you lower the value of coupling caps and bypass caps you are reducing the bass response. So you may just be eliminating the problem by having less bass, ok if the bass response is not important to you. One thing to search out on the web for is blocking distortion you do reduce this by reducing the value of coupling caps but you can also reduce the value of the grid resistor on the control grid of the tube to reduce it.
When you bias hot by reducing the cathode resistor value what may be the reason for better response is the RC time constant (resistance times capacitance) of the cathode bypass capacitor and cathode resistor is reduced. The cathode of the output tube shifts its DC value when driven hard and the recovery time could be a function of the bypass capacitor used. So instead of biasing the tube hot maybe you should try changing C9 to a lower value by calculation you could go as low as 10uf with a cathode resistor value of 270 ohms.

great... I'll give that a go!
thanks
Ryan

 

[rjohnj]

One thing to keep in mind as you lower the value of coupling caps and bypass caps you are reducing the bass response. So you may just be eliminating the problem by having less bass, ok if the bass response is not important to you. One thing to search out on the web for is blocking distortion you do reduce this by reducing the value of coupling caps but you can also reduce the value of the grid resistor on the control grid of the tube to reduce it.
When you bias hot by reducing the cathode resistor value what may be the reason for better response is the RC time constant (resistance times capacitance) of the cathode bypass capacitor and cathode resistor is reduced. The cathode of the output tube shifts its DC value when driven hard and the recovery time could be a function of the bypass capacitor used. So instead of biasing the tube hot maybe you should try changing C9 to a lower value by calculation you could go as low as 10uf with a cathode resistor value of 270 ohms.

Well it looks like changing the bypass capacitor does do the trick. I didn't have a heap of caps at hand but tried a 33uf. Actually seemed worse but then switched to a 3.3uf and guess what, flabby bottom end gone!
Is 3.3uf too low? I still plan to experiment and I haven't yet checked my voltages etc... I don't know what impact this would have?
Also there was a 100volt cap in there and I only have a 50volt - is this okay here?
Thanks Jim and SciHi for the tips on this.

 

[jim p]

3.3uf is a bit low for bass responce

If you have 3.3uf across the 270 ohm cathode resistor that would be a bit low in value equal to -3db at 180Hz. Using 10uf will be -3db at 60 Hz. As far as voltage rating the voltage across the cathode is approx 12 volts max so a voltage rating of 20 volts or more is fine. The bypassing of the cathode resistor on a pentode probably has no big effect on the gain though so it may be no big deal. I need to look at this more to make sure but it is not the same as a triode.

Just checked and the cathode impedance of the EL84 is approx 88 ohms so not bypassing the 270 ohm resistor will drop the gain by about 75%

 

[rjohnj]

miscellaneos cap and resisor values - effect of change

hi again all

Now that I am pretty happy with my amp I am just wondering about a couple of tweaks.
Can anyone tell me if I change R1 to a 1megohm (R2 is removed) if I will expect an increase in signal -and what impact would this have on gain?

What impact does changing the values of c3 or c4 have - can this help further tighten up the bottom end?

thx

Ryan

 

[chris2002rock]

Schematic anyone?

The good news is that it looks like there are no SMDs on the board.

One thing I would check is the bias. If the schematic I have is correct, the cathode bias resistor is only 100 ohms. It seems like it should be bigger.

You will want to check the plate voltage as well.

What are you trying to accomplish by modding your amp?

tung

Where did you find a schematic for this amp?

FWIW, I am getting to the point where I might just replace the whole schematic with a hand-wired replacement. If possible, I wanted to just replace the tone stack (I doubt the solid state components are entirely to blame)...but I also believe the guy who said he replaced the entire circuit (save the tubes and transformers).

I was hoping for a glance at the schematic before I rip the guts out).

Thanks in advance for any help on this.

 

[SciHi]

Where did you find a schematic for this amp?

Right here: http://www.thefret.net/showpost.php?p=120172&postcount=28

 

[SciHi]

Can anyone tell me if I change R1 to a 1megohm (R2 is removed) if I will expect an increase in signal -and what impact would this have on gain?

What impact does changing the values of c3 or c4 have - can this help further tighten up the bottom end?

So what else did you do? I put R11 (1M) across the input jack, removed R10 and everything between it and R1 (including R2), so R1 is the input grid resistor which should be in the range of 68K - 10K in most peoples opinion. A 1 M should reduce signal.

I removed C3 but also moved the grid resistor (R31) after R16. C3 should drain some highs. C4 is part of the strange tone control, I reworked the tone control to a Marshall 18 watt normal channel tone control.

 

[rjohnj]

mods so far....

So what else did you do? I put R11 (1M) across the input jack, removed R10 and everything between it and R1 (including R2), so R1 is the input grid resistor which should be in the range of 68K - 10K in most peoples opinion. A 1 M should reduce signal.

I removed C3 but also moved the grid resistor (R31) after R16. C3 should drain some highs. C4 is part of the strange tone control, I reworked the tone control to a Marshall 18 watt normal channel tone control.

I've bypassed the opamp (jumpered d10 to r2/c25 junction to get to pin 7, top of vol pot to junction to junction of r15, r29 and c28, middle of vol pot to r27 to get to pin 2 and bottom of pot to grnd)
changed c1 to 1uf - after trying many values. Helps control the farty bottom end without getting too thin.
pulled out r2, r7, r15, d9, d10, r28, c27.
cathode resistor is 270ohm and bypass cap is 0.47uf - also best after trying many to help control flab in bass.
cut board at c27 to r28
Tried pulling C5 and lowering value but got to much treble.
Amp voltages are all okay and amp sounds quite marshall-ish (or more-so than a fender) and overall pretty nice. Break-up is not over the top but I was hoping for it to be a little louder. If it's on 5 it's a nice clean tone but too quiet.
speaker is now an eminence ragin cajun and tubes are jj's (at7 instead of ax7)

I've just put in the 1M resistor at r1 to try - i think it works?.. sounds fuller maybe?? it's definitely not louder which I was originally hoping for but not much quieter either, if any. Shoud I drop this back down?

I don't mind the tone control to add a little versatility.

what do your mods between input jack and r1 do?
any other suggestions??? louder and more sustain would be good. (nb.I know it's only 5watts)

 

[SciHi]

cathode resistor is 270ohm and bypass cap is 0.47uf - also best after trying many to help control flab in bass.

I wonder if you haven't cut some volume by too low of bypass cap value on the EL84. I know lifting the cathode bypass cap is like a 1/2 power switch, I think this is what JimP was getting at with his post. I actually went higher value on the EL84 bypass cap, you can get low voltage 220 or 470 uF at the Rat Shack. Higher values are described as tightening up the bass response, I believe more than cutting it. My personal preference is to cut or limit bass in the preamp, and tighten up bass in the power section. I did go with 1uF bypass caps on both preamp valves.

 

[rjohnj]

I wonder if you haven't cut some volume by too low of bypass cap value on the EL84. I know lifting the cathode bypass cap is like a 1/2 power switch, I think this is what JimP was getting at with his post. I actually went higher value on the EL84 bypass cap, you can get low voltage 220 or 470 uF at the Rat Shack. Higher values are described as tightening up the bass response, I believe more than cutting it. My personal preference is to cut or limit bass in the preamp, and tighten up bass in the power section. I did go with 1uF bypass caps on both preamp valves.

I don't think it's the bypass cap because I tried everything from 1000uf down to the 0.47 and the level was around the same. Maybe it's about as loud as it gets?

I'm interested in the 1uf bypass caps on both preamps - what positions are these caps?

 

[jim p]

maximum volume

For what it is worth to get the maximum volume you should look into biasing the amplifier if you have not already. The other thing affecting the volume is the transformer having a 20:1 ratio which is more suited for a 16 ohm speaker then an 8 ohm speaker. So if you need the maximum power transfer out of the amplifier you need to either use a 16 ohm speaker or get a new output transformer. So that means spending 30 to 60 bucks for a new transformer or whatever the speaker will run you. For transformers there is Hammond 125 series, Edcor, OT8SE and OT10SE as a few choices. Look over the stuff at Sewatt web site for the Valve Jr to get an idea of the differences. On output transformers the higher the primary inductance the better the bass response but it is not specified in most cases so rule of thumb is the bigger and the heaver the better the bass.

 

[rjohnj]

For what it is worth to get the maximum volume you should look into biasing the amplifier if you have not already. The other thing affecting the volume is the transformer having a 20:1 ratio which is more suited for a 16 ohm speaker then an 8 ohm speaker. So if you need the maximum power transfer out of the amplifier you need to either use a 16 ohm speaker or get a new output transformer. So that means spending 30 to 60 bucks for a new transformer or whatever the speaker will run you. For transformers there is Hammond 125 series, Edcor, OT8SE and OT10SE as a few choices. Look over the stuff at Sewatt web site for the Valve Jr to get an idea of the differences. On output transformers the higher the primary inductance the better the bass response but it is not specified in most cases so rule of thumb is the bigger and the heaver the better the bass.

Yeah I don't think I'll be putting any more money into this thing. It's a good little practice amp as it is but I don't think it will ever get loud enought to gig with - unless it's mic'd up. Do you guys think yours are?
Also, to buy speakers and transformers over here (in Australia) is much more expensive than there.
I'll be heading to the UK on Monday for the next 6 months and can't take an amp anyhow - think I'll tackle a Tweed Twin build when I get home.

 

[SciHi]

Yeah I don't think I'll be putting any more money into this thing. It's a good little practice amp as it is but I don't think it will ever get loud enought to gig with - unless it's mic'd up. Do you guys think yours are?

I mic mine in church but only run the preamp gain on about 3 or 4.

I spend a lot of time on SEWATT valve junior forum, most of the technical discussions are relavent to the v5 or any single ended amp. Here is a quote from cGil in regards to the EL84 (discussion is about vj, C5 = C9 on v5);

"C5 is a bias bypass cap. This is required to get the max available power out of your tube. Go below the stock 25uF/35v, and you lose power. The bottom end tone will be softer and loose with the stock 25uF bypass cap. Depending on the speaker used, the bottom end can sound a bit flubby. Increasing this value makes the bottom end tighter. 1000uF/50v caps are very popular for tightening up a flabby bottom, but any value between 22uF and 2200uF will suffice." http://www.sewatt.com/comment/191746

VJ's come with 220R cathode resistor, the reverse problem to the v5. The 1000uF EL84 bypass cap is heavily used in various vj mods.

 

[SciHi]

I'm interested in the 1uf bypass caps on both preamps - what positions are these caps?

For the preamp v1a and v1b cathode bypass caps are C1 and C8, so I run both of these at 1uF on the v5. I have dark HBs (DiMarzio) and really need to keep a tight bottom end and use the coupling cap (C2) and tone stack to limit the bass/gain in the preamp. The tone stack reduces significant gain, so much that I never get any of the buzzy preamp overdrive even when dimed. I put in a master volume because I wanted the extra control, but mostly run the amp with low preamp gain setting and master volume dimed (maximum clean and EL84 chime).

I am really not interested in an OT upgrade either. I have used the amp through other speaker cabs, 1 and 2 12's, and it was a significant improvement. As jim stated on the OT, with a single 16 ohm Jensen Mod 12-70, the amp sounded particularly good. I already had a selection of speakers so it was no cost to try. I ended up with a Celestion Tube 10 in the v5, it was just best of what I had on hand that would fit into the cab. I have put little to nothing into the amp after the initial $79 purchase price (free shipping), I already had parts from other projects. Best investment in an amp I have made!

On others amps I have used 0.68uF cathode bypass caps on v1a. On my value junior I don't even have the v1b bypass cap, but I run it without a tone control. But on both amps I am running small coupling caps on v1a, 0.0047uF. I got a range of Mallory and orange drop (715, 716, 225s) caps from 0.001 to 0.0068uF to fine tune the amp to the guitar. I use mostly HBs so that is how I set up my amps. I have the split-single coil switch on my HBs so I can go to a thin "nfb like" rhythm tone.

A large group of us are all doing 5e3 builds (or vj conversions) from PPWATT. This was headed up by a fellow country man of yours, jamesrr, it is around 14 watts with 6v6's. You might want to check it out. (I may need to get a single coil tele for that amp!) http://www.ppwatt.com/node/16476

 

[SciHi]

tubes are jj's (at7 instead of ax7)

Missed this earlier, but many say that you should not use the 12at7 in preamp gain stage (designed for 12ax7), even more important in v1 position and with only one preamp tube. The 12ax7 may be too much gain, I would recommend going with 5751 if you want a lower gain tube (or reduce gain with tone stack/divider, etc). I think the 12at7 is a drive tube, used as PI, tremelo, or reverb, etc. It has a different current draw, bias, etc. Maybe Jim P or Rock_Mumbles can quote some of the specs on that tube. So put back in the 12ax7 and see how it sounds...

EDIT: OK, here is a data sheet on the 12at7; http://tubedata.milbert.com/sheets/093/1/12AT7.pdf

 

[rjohnj]

Missed this earlier, but many say that you should not use the 12at7 in preamp gain stage (designed for 12ax7), even more important in v1 position and with only one preamp tube. The 12ax7 may be too much gain, I would recommend going with 5751 if you want a lower gain tube (or reduce gain with tone stack/divider, etc). I think the 12at7 is a drive tube, used as PI, tremelo, or reverb, etc. It has a different current draw, bias, etc. Maybe Jim P or Rock_Mumbles can quote some of the specs on that tube. So put back in the 12ax7 and see how it sounds...

EDIT: OK, here is a data sheet on the 12at7; http://tubedata.milbert.com/sheets/093/1/12AT7.pdf

It may be due to poor quality tube as stock but the 12at7 sounds 10 times better. of course the ax7 is a little louder and has more gain but it is more brittle and colder sounding. the at7 is sooo much nicer, rounder and warmer. All my voltages and bias measurement is okay. Unfortunately I'm off overseas for a while in a day or so and can't take the amp to keep messing around with it so will have to wait til I get back. Though will try the 5751 - can't hurt.

 

[jim p]

Peavey valve king for 99 bucks

Well being the Crate V5 has gone away here is a 99 buck tube amp with a bad speaker you can buy.
http://www.music123.com/Peavey-ValveKing-Royal-8--5W-1x8-Tube-Combo-Amp-481661-i1383113.Music123

 

[jim p]

squish?

Going back to the posts about farty bass sound and the cathode bypass capacitor value by this article http://www.aikenamps.com/Sag.html in the last paragraph about squish. It looks like the lowest value of bypass capacitor would be the way to correct this on the output tube. Also all the fixes you would use for blocking distortion lower value coupling caps or lower value grid resistors to lower the time constant if a DC shift occurs in the amplifier. The thing to note when you lower the coupling cap values or the grid resistor values you are also lowering the bass response.

On blocking distortion Aikens amps also has a posting on that you may want to check out.

 

[rjohnj]

Going back to the posts about farty bass sound and the cathode bypass capacitor value by this article http://www.aikenamps.com/Sag.html in the last paragraph about squish. It looks like the lowest value of bypass capacitor would be the way to correct this on the output tube. Also all the fixes you would use for blocking distortion lower value coupling caps or lower value grid resistors to lower the time constant if a DC shift occurs in the amplifier. The thing to note when you lower the coupling cap values or the grid resistor values you are also lowering the bass response.

On blocking distortion Aikens amps also has a posting on that you may want to check out.

hmmm.... some of this is still a bit beyond me but I get the concept and I've come along way since I started on this amp a few weeks back. I think in a way I kind of fluked getting my amp to where it is with quite a bit of experimentation and some good advice on this thread pointing me in the right direction.
Other than wanting a little more volume for louder playing clean (bigger amp needed for that obviously), it sounds great. I'm sure there is dozens of combinations of resistors and caps that could get rid of the muddy bottom end I was getting but it is pretty much gone now with the mods I made. Just one of my guitars had issues with the neck pickup and after lowering it on the bass side it is fine.
I plugged in my pedals to it last week for the first time and I was blown away - for one I could get a great volume boost but it sounded better than I could have imagined. My tube screamer and London fuzz worked unbelievably well through it and I couldn't have been happier. If I whacked a different badge on this and put it in a store there's no doubt it'd sell for a bucket load more.
Thanks again for helping me get there.
As for that new combo I'm just not sure what Crate are trying to do. Coming from a Marketing strategy background I can't quite figure it. It looks cheap and nasty and to me I think starts to position the brand in the budget end - whereas crate have historically made some good amps. If they wanted to make money and have a great reputation for a 5w amp - they'd just modify the circuitry a little, like we have, and perhaps throw in a better speaker. A few bucks extra but 10 times the amp that would sell like hot cakes and reinforce the brand as a quality one - whether budget priced or not.

Ryan

 

[jim p]

Differential reverb recovery amplifier

I have made a change to the reverb recovery amplifier circuit from what I originally used when adding reverb to the Crate V5 on these posts http://www.thefret.net/showthread.php?t=9379&page=11
For the recovery amplifier it looks like the best op amp to use at a reasonable cost is the NE5532. Also to reduce noise I am using both op amps in the dual package to make the recovery amplifier a differential amplifier to help lower noise pickup from the tank to the recovery amplifier. So another change that needs to be made will be to isolate the RCA jack on the output of the reverb tank as well as the input of the reverb tank. Also a ground wire will need to be added from the reverb tank to the chassis of the amplifier. Along with this if you are into making up your own cables would be to use a twisted pair inside of a shielded cable for the reverb tank output. The twisted pair should be connected to the inner and outer connectors of the RCA jack on the reverb tank while the outer shield would be connected to ground near the recovery amplifier the shield should be left floating on the reverb tank side.

So if you have not yet added reverb or have some noise pickup that you would like to try and eliminate you may want to go with this differential recovery amplifier.


If you have ever built a jfet buffer for your guitar output where you install a jfet right on the output jack of the guitar I just realized how to apply this to the reverb tank output. I have simulated a differential jfet buffer located in the tank that should balance and lower the output impedance of the reverb tank. With this as the input to a differential amplifier the noise from the tank should be close to none. I will test this out and if it works out will post the schematic.

 

[timmer114]

I accidently pulled up a solder pad on C24 - no power to led or preamp now..

I think I burned something on mine. I had the v5 working just the way I wanted it, and when I went to change the c24 cap, the trace pulled up from too much heat soldering. I tried to make a jumper but I dont get any power light now,or preamp tube glow. Power tube works, amp turns on, just no power light or preamp tube, I wonder if frying the C24 trace caused this, though the jumper seems fine, or... if I bumped a nearby resistor or op amp with the soldering iron if that is what is causing the issue..

I can't seem to track down where I went wrong here. Let's say C24 socket is toast, the trace/pad came off the pcb...I should be able solder a hair up the trace itself and get a connection no?

Anyone have any ideas why I cant get power to the LED or to the preamp? The preamp is getting some voltage, it just won't come on. checked all fuses and connections, this all started when I pulled up C24, and the leg snagged on the pad and tore it up from the pcb. I wonder if there is a place I can jumper past the C24 pad..

Desperate here lol.

 

[jim p]

Look for short on +/- 15 volts

Look to see if one of the supplies that go to the op amp is shorted this would be the +14.7 and -14.7 volt supplies. Check for blown fuses on F1 and F2 this is the ac secondary that supplies the +/- low voltage supplies

I was just looking over your problem again I am guessing you tried to remove the capacitor with the PCB installed in the amplifier? The component leads are bent on the bottom of the board so you need to straighten them before you remove them. If you don’t there is plating in the hole that the component is soldered to that may be ripped out when you pull the component lead out. If you did that you may need to make repairs to both sides of the board.

 

[rock_mumbles]

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 "amplification". Do you have +/-14V on diodes D9 and D10, according to the schematic this should be on the striped end of D9 and on the not-striped end of D10? The LED power comes off of the same power supply as D9 and D10. IF you don't have +/- 14V maybe check the two fuses on the low voltage power supply F1 and F2.

If you want to test the rest of the circuit, the preamp tube on, you could use a jumper wire from R10 (off of input jack) to R1 (input to preamp tube), note the amp will NOT have a volume control so it will be full volume

 

[timmer114]

Thanks for the replies guys, I really appreciate it.

Your right, I did pull up C24 from the top, big mistake. I checked the fuses, nothing blown there. I am thinking your right in that I will have to repair both top and bottom. Top seems simple enough to repair as I can visually see the traces. The bottom though.. im not so sure what I can do as the traces don't show through the bottom.

I'll have to pull the PCB tonight and see what I can figure out.

Okay so as Rock points out, the LED and C24 are on the same circuit I take it? I wish I had the board in front of me but I am on lunch break at work. I think there is hope here, I did get 300 volts off the preamp with the multi tester, so it is getting some power, guessing that the circuit is open though with C24 trace damaged. I'll drain the caps tonight and pull the board out. I think I need to figure out how to get C24 working again. I can still use the mounting holes and the top traces seem ok, it's the trace underneath that is giving the problem. So.. even if I do have the top traces soldered as I do right now, it's not going to work until I can figure out how to close the circuit underneath the board in C24.

Thanks again, your giving me some hope here =)

 

[rock_mumbles]

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. Then from what you can see on top check for continuity on each side of C24 to the "neighboring" component(s). Then you can find out where your trace problem is.

 

[timmer114]

Well, I did some continuity testing and found that two fuses did indeed blow, though they don't look it. I replaced them, and I do have power now to the LED and preamp, however I just get an annoying hiss. I am guessing this is where c24 comes into play.

I can see the top traces, but have no idea what was going on underneath the board, as you look at the board, underneath c24, it doesn't appear the bottom pads are hooked to anything.

But at least I have power again, just no sound. My tone cut control I made however, does adjust the tone of the hissing, just no input signal coming from my guitar.. I'll keep workin on it. Still looking to see if there is somewhere else I can jumper C24.

I wonder if the op amp blew, that would account for the lack of input signal and hissing I think.. hrmm I do have a burr brown op amp laying around somewhere, or I can just grab a new TL072 from radio shack. Thanks guys, still workin it out =)