Sorry mate, I don't understand what you mean by 1.23v? We are measuring resistance or continuity from the junction of R20 and 37 and C15. There is no voltage to measure.
I just got confused, my bad, can you show me or explain how I am supposed to measure it using my multi meter or otherwise?. I ordered the resistors, but I won't lie I am considering just giving up on this. I must've done something really bad to this. I just don't know how much longer I should go on before it's like "yeah I replaced everything in this"
Hey, no worries, don't let it go now, there is light at the end of the tunnel. With your meter in resistance mode or continuity measure from the junction of R20 and 37 to the positive post of C15. It's the short trace only about 1 cm. We want to confirm there is still a connection there.
If you think the resistors are okay, they didn't look burned as the tracks on the PCB, you can put them back in to at least test it again. It may just have been a dry solder joint that caused the chaos on the pads.
If you go ahead first check then voltage at R37, it it back up to similar to what you are getting on the negative side you can then go back to check the voltage at the opamp pins 4 and 8.
If you think the resistors are okay, they didn't look burned as the tracks on the PCB, you can put them back in to at least test it again. It may just have been a dry solder joint that caused the chaos on the pads.
If you go ahead first check then voltage at R37, it it back up to similar to what you are getting on the negative side you can then go back to check the voltage at the opamp pins 4 and 8.
I think you should unsolder everything from that PCB, check the correctness of each part separately, get a new PCB and start from the beginning. There was thermal overload in many places and that PCB is no longer reliable. Maybe there was carbonization of the PCB locally that now conduct current past the electronic parts.
That's certainly not necessary, at this stage anyway.
1nfinity, have close visual inspection of both sides of the PCB. Can you identify any other burned areas? If so we can have look at those but so far all we have seen is this area around R20 and 37 and there is nothing there stopping this project from working.
They brought me a couple of similar things, DIY burned devices, burned PCBs and parts. The fastest and safest fix is always a new PCB (if feasible). If not, then I patch it because I have no other choice. I remove all the parts fast with a vacuum desoldering gun, measure everything, discard the defective parts, and when I reassemble with the correct components it works immediately, no time wasted. And it looks the best and is reliable in the long run.
R21 and R38 kinda look a little burned, I sent previous pictures, sorry hard to see.
I want to at least try and see where I can get with this in hopes that things work. I am also learning a lot of things to check because I am doing this
Absolutely 1nfinity, I reckon the fix is just around the corner and as you say, doing is learning. You built this to start with and you will get it working again.
Check all around the board where you have already replaced burned resistors near the mosfets for damaged tracks on the PCB. Once all is checked and the parts are back in you can go through the voltage test points you have measured before to see if they are where they should be.
Check all around the board where you have already replaced burned resistors near the mosfets for damaged tracks on the PCB. Once all is checked and the parts are back in you can go through the voltage test points you have measured before to see if they are where they should be.
Can I suggest you clean this board with a PCB cleaner, then investigate further ? It's difficult to see the track to pad connection. I've had the great pleasure of repairing several Musical Fidelity amplifiers which have been slowly cooking themselves over the years and now I use a scalpel to gently scrape away burnt board then clean it with a brush and Fluxclene from Electrolube. It's not a nice chemical but it does clean everything from a board very easily and leaves it sparkling and it's very easy to then see the condition of tracks and pads. You might just about get continuity with a meter but when the amp is running the joint doesn't work.
I'd also suggest doing what Zum911 said, join the leads but also use a cut off lead to join to the capacitor too, in case the track is poor.
Black PCB, hardly anything will be seen. Looks cool, but that paint is opaque. Also, the heatsinks are not separated from the PCB (1-2mm), there may be short circuits through the protective paint.
Well, further testing, I've not changed the capacitors on the voltage regs yet, Sparkos recommend a particular 100uF Panasonic but I've left the Audio Notes in place, so nothing has changed between op amps, apart from moving a couple near the op amp so I can fit adapters and the Bursons in there.
The Sparkos voltage regs are running at about 47C, the output mosfets about 40C and the Burson V7 is getting up to just under 50C, warmer than I expected but still sensible.
OPA2134 - probably the best value, cheap and sounds really good, very balanced, if didn't want to spend anymore, I'd be happy that I had probably 90+% of the benefit for about 5% of the cost compared to more expensive op amps. I've used these before but not heard them sound quite so good as in whammy.
OPA2227 - similar to 2134 but might have more treble detail, difficult to tell because the midrange was a slightly muddled. Not worth the extra few euros over the 2134 but if you've already got one, a good option.
Muses02 - the bass is a bit bloaty, it often over shadows the lower mid too which then also sounds a bit too warm. Overall for Jazz, folk and vocal it's a really nice choice, does add warmth to the music, but possibly too much for some electro and modern music. I'd probably not buy it over the 2134, given it's about 60 euros.
The Burson V7 vivid is just stunning in Whammy, it's better overall than any of the other op amps I've tried so far. The bass is better than Muses02, full and detailed but tight and defined, the treble is more detailed, especially with cymbals and all the echos they often produce. It seems some op amps can do one or the other but the Burson V7 seems able to pull everything together at the same time. Even some Dave Brubeck sounds more lively and engaging and some of those recordings are not great.
Aljamiado on the album Beyond the Double Bass by Renaud Garcia-Fons, is beautifully presented, the bass is full and deep, with the other instruments layered on top like a french salad. It's the best I've heard Whammy, really impressive.
At about 90 euros, it's not cheap but the sound quality does justify the extra over the Muses02. I almost got a shock at how the vocal version of Tom's Diner sounded with the V7, Suzanne Vega's voice was warm and very detailed and the echo and reverberation was much clearer than I'd heard before.
I just need to add some ventilation to the case so there's some air flow to stop it getting too hot with the Sparkos regs and V7, then try the Sparkos recommended Panasonic caps on the regs.
The Sparkos voltage regs are running at about 47C, the output mosfets about 40C and the Burson V7 is getting up to just under 50C, warmer than I expected but still sensible.
OPA2134 - probably the best value, cheap and sounds really good, very balanced, if didn't want to spend anymore, I'd be happy that I had probably 90+% of the benefit for about 5% of the cost compared to more expensive op amps. I've used these before but not heard them sound quite so good as in whammy.
OPA2227 - similar to 2134 but might have more treble detail, difficult to tell because the midrange was a slightly muddled. Not worth the extra few euros over the 2134 but if you've already got one, a good option.
Muses02 - the bass is a bit bloaty, it often over shadows the lower mid too which then also sounds a bit too warm. Overall for Jazz, folk and vocal it's a really nice choice, does add warmth to the music, but possibly too much for some electro and modern music. I'd probably not buy it over the 2134, given it's about 60 euros.
The Burson V7 vivid is just stunning in Whammy, it's better overall than any of the other op amps I've tried so far. The bass is better than Muses02, full and detailed but tight and defined, the treble is more detailed, especially with cymbals and all the echos they often produce. It seems some op amps can do one or the other but the Burson V7 seems able to pull everything together at the same time. Even some Dave Brubeck sounds more lively and engaging and some of those recordings are not great.
Aljamiado on the album Beyond the Double Bass by Renaud Garcia-Fons, is beautifully presented, the bass is full and deep, with the other instruments layered on top like a french salad. It's the best I've heard Whammy, really impressive.
At about 90 euros, it's not cheap but the sound quality does justify the extra over the Muses02. I almost got a shock at how the vocal version of Tom's Diner sounded with the V7, Suzanne Vega's voice was warm and very detailed and the echo and reverberation was much clearer than I'd heard before.
I just need to add some ventilation to the case so there's some air flow to stop it getting too hot with the Sparkos regs and V7, then try the Sparkos recommended Panasonic caps on the regs.
Hey sorry, I just took a break from this, I'll be back on it tomorrow. I've been addicted to some video games haha
That's what I concluded too (V7 Classic), but it's heated up a lot for my taste. Maybe I'll get it back, you never know. In autumn, when the heat passes. 😁
The Muses02 has everything that the Signetics NE5532 has in the bass section, but is cleaner in the mids and especially in the highs. If someone likes a bassy sound, and can tolerate a bit more muddy mids and highs, the Signetics 5532 (or OPA2604) is probably the best choice among cheap opamps. The final impression depends a lot on headphones, or speakers if it is used as a Line preamp (my case).
Muses02 requires compensation (33pF for my version and 68pF for @mikorist version). It can sound weird without it. An oscilloscope and generator are necessary to determine the exact value.
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Another whammy coming right up. Looks like i did not mess up the measurements.
Custom PCB? Nice looking and compact. Heatsinks for output transistors can be smaller. It all depends on how much quiescent current you planned.
Are those boards available to buy ? Are you running with more power ? I've got a Lehmann BCL (genuine) to fix then I'm building a Lehmann BCL clone, but I was considering a Whammy from scratch, rather than fixing somebody else's with a new board. If the boards are available I'd be interested.
Yeah the heatsinks are overkill(like to eversize them) but this was the only one in stock and my design goal was that the E12 had to fit between the heatsinks.
I dont even know if it will work without major issues. My last two project ended in faliure as on paper it looked fine but then after assembling them i realized that i created horrible ground loops and channel crosstalk. I'm gonna run then underpowered but this was the only heatsink in stock. Sorry its not for sale.