greenskull wrote:I didn't have a 5M pot so I went with a 330k fixed resistor and a 1M pot.
Green, I have a 1M pot, which resistor did you replace for the 330k? I think you change this:
Now my SFM works... a little, there's a sound like a bird when I play my guitar with the effect, what could it be?
Thanks to Rhandy, Green, Lucifer!
When I'm attacked by Christians, I proudly repond: Your GOD was nailed to the cross, mine has a hammer in his hand, draw your own conclusions... Nergal (Behemoth)
Yes, change that to 330k. This effect is REAL sensitive and touchy to picking attack..... setting the sensitivity control for high strings is too much for low strings sometimes!!
The "bird sound" is a mystery. Does it make the sound when not playing or does sound like the effect is wrong when plucking strings?
greenskull wrote:The "bird sound" is a mystery. Does it make the sound when not playing or does sound like the effect is wrong when plucking strings?
This "bird sound" appears when plucking strings. I think there's something wrong with the IC2 because if I put the 50k pot in 3 o'clock, this "bird sound" doesn't appear and the effect works but if I turn left to right, that sound appears with high volume and the effect dissapear
I replace the IC and transistor that I used first for new ones, and still making that sound...
Any suggestions?
When I'm attacked by Christians, I proudly repond: Your GOD was nailed to the cross, mine has a hammer in his hand, draw your own conclusions... Nergal (Behemoth)
Well, maybe just a wild guess, but make sure you have that pot wired correctly. Also as last resort check to make sure there are no shorts between traces on your pcb as well.
You can get some weird sounds with this thing by hitting the strings too hard if you aren't careful with sensitivity setting...... your signal can disappear!
Maybe not the best envelope filter to begin with. Good it's a low parts count build, but there are better circuits out there now.
Thanks Green, this pedal is for a friend who plays bass, and is a challenge to me!
Tomorrow I will check the pot wiring.
Thanks a lot my friend!
When I'm attacked by Christians, I proudly repond: Your GOD was nailed to the cross, mine has a hammer in his hand, draw your own conclusions... Nergal (Behemoth)
Well... I check the pot wiring and is correct... I made a new one and makes the same "bird sound"... the pcb is ok... i tried to change 2M2 resistor for less value and the "bird" stands still... I don't know what else to try...
When I'm attacked by Christians, I proudly repond: Your GOD was nailed to the cross, mine has a hammer in his hand, draw your own conclusions... Nergal (Behemoth)
negrosinfe wrote:Well... I check the pot wiring and is correct... I made a new one and makes the same "bird sound"... the pcb is ok... i tried to change 2M2 resistor for less value and the "bird" stands still... I don't know what else to try...
Could be oscillation caused by the long length of your wires. You could shorten them quite a bit, like you would if installed in pedal box. Worth a try before giving up.
Dear friends: I surrender... I try to shorten the cables and the "bird" sound continues... i don't know what else to do...
The 10k resistor among collector and emmiter... is that correct?
Thanks for all the information!
When I'm attacked by Christians, I proudly repond: Your GOD was nailed to the cross, mine has a hammer in his hand, draw your own conclusions... Nergal (Behemoth)
negrosinfe wrote:Dear friends: I surrender... I try to shorten the cables and the "bird" sound continues... i don't know what else to do...
The 10k resistor among collector and emmiter... is that correct?
Thanks for all the information!
Sorry to hear that. You mean 10k across base and emitter? That is correct.
If you have the 10k across collector and emitter, that could the problem!
negrosinfe wrote:Dear friends: I surrender... I try to shorten the cables and the "bird" sound continues... i don't know what else to do...
The 10k resistor among collector and emmiter... is that correct?
Thanks for all the information!
Sorry to hear that. You mean 10k across base and emitter? That is correct.
If you have the 10k across collector and emitter, that could the problem!
2N5088 has 1: Collector, 2: Base, 3: Emitter, right? So if I'm correct the 10k goes across C and E:
Besides I was thinking if could try to put a 220 ohm resistor across emitter and ground... could it be possible to eliminate the bird sound?
When I'm attacked by Christians, I proudly repond: Your GOD was nailed to the cross, mine has a hammer in his hand, draw your own conclusions... Nergal (Behemoth)
i'm still building you one but, i've got some other jobs to do and life gets in the way of things sometimes.
cheers.
Rhandy: take it easy my friend! In the meantime I will try to make it work! (or not? )
Thank you very much!
Max
When I'm attacked by Christians, I proudly repond: Your GOD was nailed to the cross, mine has a hammer in his hand, draw your own conclusions... Nergal (Behemoth)
Just found this site while searching the internet to show my little grandson, who is very interested in electronics, some of my 70's designs and modifications including the frequency shift and aluminum case of the existing Seamoon Funk Machine, creating the V2. (I designed the Seamoon TCP and the Seamoon Studio Phase, first FET based then Reticon BBD) and was surprised to find there is still interest in building a Funk Machine type effect.
The transistor is a simple NPN. There was a package of 2N3565 's at Seamoon with a higher hfe used and the house numbered 40006's were inexpensive over runs purchased from Godbout electronics. The direct connections on the board to the transistor are; Base = to 33K and 10 K junction, Emitter = to ground, with the10K ground. Collector = to 47K and .005 cap junction. So the transistor has a 10K across the base and emitter. The only ground connection to the transistor is the emitter.
Negrosinfe post diagram has a RED arrow with a question mark, that is the INPUT. The other post reference has an added a RED line grounding the whole Collector trace. Remove Red line and if required reverse position of that particular transistor. The RED letters on the diagram should read C, B, E. I hope this helps a little.
P.S. The reason a 5 meg pot was incorporated is simple, it's what they had in stock and wanted to use if it worked. When I added the 5 meg pot to circuit the gain resistor was reduced from 470 K in the original circuit to 47 K. I had added multiple features to expand and improve the function of original circuit however they had a large number of old PC boards in stock from their vender ready to load so any added improvements had to be shelved temporarily. So we decided to modify the old boards with only the Frequency Shift control and fill incoming orders to do a final run of the V2's, then layout the new board with the circuit additions and create Funk Machine V3. The problem, the case was to small for the new controls which meant designing a new wider case. Jerry Pynckel
Wow, not very often you met people who invented all the stuff we're discussing here.
Feel welcome to come over here again to chat und discuss and maybe improve and invent old and new stuff. I know many people here would appreciate that.
Dear Jerry: it's an honour to share this forum with you, your Funk Machine is the best envelope filter that i've ever heard.
When I'm attacked by Christians, I proudly repond: Your GOD was nailed to the cross, mine has a hammer in his hand, draw your own conclusions... Nergal (Behemoth)
Have to say I really appreciate the positive response from everyone interested in the Funk Machine V2 and look forward to more discussions in the future. I also like the idea of you actively constructing and experimenting with the circuits. Hey Bart, it has been a while, will contact you this weekend. In our storage we did find a list I had written and left for John in September '75 on the improvements that could be made or implemented to the Funk Machine to produce the V2.
I enjoyed designing at Seamoon, it was a good work environment plus John and Michael wanted to use all the effects I had designed before joining Seamoon. This would have given them a full line of effects. You might also be interested to know that to test a new products/effects function, I would take the prototype and use it in our little 3 piece rock band on different instruments, while playing around the bay area on weekends. If it lived up to to design specs and live performance, in other words did what it was supposed to, we would take it next door to the Cosmos Factory and have Credence Clearwater test out the unit. Jerry Pynckel