SpringReverbFan1234
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- Build Rating
This report is about assembling one of these a second time. The first one sounded so good I had to build another. I posted about the first in another thread: https://forum.pedalpcb.com/threads/griffin-ricochet-surfybear-clone.18862/post-362475
This build came about mainly because I personally consider the Tone and Dwell knobs to be backward on the schematic/board. If you check the Griffin Schematic, these pots have pin 3 toward ground. Which looks like it carried over from the Surfy Schematic. The old 6G15 schematic looks like how I'd want it; pin 1 to ground.
So I mounted long pin pots on the component side and left out the opamp mixer. This technique worked really well. It only required low profile capacitors and flipping some hardware around. The DC jack is on the opposite side, the stomp pcb got flipped too, and the in/out jack wires run a bit further to keep them on the proper sides. Now Dwell and Tone are good because they got pins 1 and 3 flipped. For the Mix knob CCW is Dry, CW is Wet. The knob is more useful on the Dry side though. An audio Log potentiometer would've been perfect here but I used a Linear. Keep in mind I basically flipped everything, mounting the pots the normal way would probably need a C taper for Mix, an A taper might be detrimental.
The enclosure is a cream 1590BB2 from Tayda. I made the drill template by measuring with calipers. All the holes aligned and fit perfectly except the LED. Which still fit ok but the hole is like 2mm to far away from the switch. The extra enclosure height gave room for the pot pins, the board, the in/out wires, and this time two stick on heatsinks. (There's one on the component side that's not visible in the pictures.) The three knobs in an L shape is ugly but I wanted to stick with board mounted pots. The knobs are the mini chicken head kind.
Last time I got lucky that all five 2n5457 I checked were within spec. This time only 6/10 were even close to the spec of -1.58V 3.25mA. I had a low bias voltage at TP1 before, so this time I premptively increased R13 to 56k instead of 47k. Maybe it helped, the bias voltage is 5.76 volts which is higher than before. Probably should've used like a 100k trimmer. I might be wrong but I think increasing this resistor increases the voltage. And R15 is still 1.5 ohms, as it should be. Not 1.5k.
Next time I'd do it flipped like this again but use the opamp mixer and use A taper pots for Dry Cut and Wet Cut. Or C taper pots and cut/swap pins 1 and 3 to make them work normally. And I'd use a trimmer for R13. Two builds is probably enough though. Now I can run them in stereo.
This build came about mainly because I personally consider the Tone and Dwell knobs to be backward on the schematic/board. If you check the Griffin Schematic, these pots have pin 3 toward ground. Which looks like it carried over from the Surfy Schematic. The old 6G15 schematic looks like how I'd want it; pin 1 to ground.
So I mounted long pin pots on the component side and left out the opamp mixer. This technique worked really well. It only required low profile capacitors and flipping some hardware around. The DC jack is on the opposite side, the stomp pcb got flipped too, and the in/out jack wires run a bit further to keep them on the proper sides. Now Dwell and Tone are good because they got pins 1 and 3 flipped. For the Mix knob CCW is Dry, CW is Wet. The knob is more useful on the Dry side though. An audio Log potentiometer would've been perfect here but I used a Linear. Keep in mind I basically flipped everything, mounting the pots the normal way would probably need a C taper for Mix, an A taper might be detrimental.
The enclosure is a cream 1590BB2 from Tayda. I made the drill template by measuring with calipers. All the holes aligned and fit perfectly except the LED. Which still fit ok but the hole is like 2mm to far away from the switch. The extra enclosure height gave room for the pot pins, the board, the in/out wires, and this time two stick on heatsinks. (There's one on the component side that's not visible in the pictures.) The three knobs in an L shape is ugly but I wanted to stick with board mounted pots. The knobs are the mini chicken head kind.
Last time I got lucky that all five 2n5457 I checked were within spec. This time only 6/10 were even close to the spec of -1.58V 3.25mA. I had a low bias voltage at TP1 before, so this time I premptively increased R13 to 56k instead of 47k. Maybe it helped, the bias voltage is 5.76 volts which is higher than before. Probably should've used like a 100k trimmer. I might be wrong but I think increasing this resistor increases the voltage. And R15 is still 1.5 ohms, as it should be. Not 1.5k.
Next time I'd do it flipped like this again but use the opamp mixer and use A taper pots for Dry Cut and Wet Cut. Or C taper pots and cut/swap pins 1 and 3 to make them work normally. And I'd use a trimmer for R13. Two builds is probably enough though. Now I can run them in stereo.