Newbie GlassWare Aikido All in One Questions
I am fairly new to DIY electronics and I am fairly weak in theory. I have successfully completed several Elliott Sound Products projects and built a Ceriatone guitar amp but both of those companies have very good instructions and support.
I have just purchased a GlassWare All in One 9 Pin line stage board. I apparently got the newest revision board and a previous revision user guide. There are a couple of changes that I can not figure out on my own. I emailed GlassWare but no reply.
The main thing I have a problem with is there is now a RC filter on the output of the HV bridge rectifier and the board came with a selection of resistors for the filter. The resistor go from 10R to 1K and I don't know how to choose the correct one.
Problem two is a definate newbie question. I ordered the GlassWare stepped attenuator. I ordered it after the board order and it has been ten days with no word from GlassWare. Assuming I ever get the attenuator where would it go? Before the input or after the output?
Any help will be greatly appreciated.
Solder on,
George
I am fairly new to DIY electronics and I am fairly weak in theory. I have successfully completed several Elliott Sound Products projects and built a Ceriatone guitar amp but both of those companies have very good instructions and support.
I have just purchased a GlassWare All in One 9 Pin line stage board. I apparently got the newest revision board and a previous revision user guide. There are a couple of changes that I can not figure out on my own. I emailed GlassWare but no reply.
The main thing I have a problem with is there is now a RC filter on the output of the HV bridge rectifier and the board came with a selection of resistors for the filter. The resistor go from 10R to 1K and I don't know how to choose the correct one.
Problem two is a definate newbie question. I ordered the GlassWare stepped attenuator. I ordered it after the board order and it has been ten days with no word from GlassWare. Assuming I ever get the attenuator where would it go? Before the input or after the output?
Any help will be greatly appreciated.
Solder on,
George
Last edited:
Reverse order: before the input.
The resistor is chosen by looking at the current draw of the circuit. If that current draw is I, the raw supply voltage before the resistor is V1, and the desired supply output voltage is V2, then R = (V1 - V2)/I. Wattage should be 3 or 4 times bigger than I*(V1 - V2).
If you want to do trial and error, start with a lower value of resistor- the Aikido circuit works best with higher supply voltages. If the supply isn't clean enough (e.g., you can hear buzz on the preamp output with the volume turned down), you can increase the resistor.
The resistor is chosen by looking at the current draw of the circuit. If that current draw is I, the raw supply voltage before the resistor is V1, and the desired supply output voltage is V2, then R = (V1 - V2)/I. Wattage should be 3 or 4 times bigger than I*(V1 - V2).
If you want to do trial and error, start with a lower value of resistor- the Aikido circuit works best with higher supply voltages. If the supply isn't clean enough (e.g., you can hear buzz on the preamp output with the volume turned down), you can increase the resistor.
Thanks for the replies.
As far as delivery of the board is concerned I believe that it was pushing three weeks from the date of order. I get boards from Elliott Sound Products quicker than that and ESP is in Sydney, Australia and I am in Pennsylvania, USA.
I still need an answer on where to insert the level control? For some reason I think that it would go before the input.
Assuming that I eventually get the GlassWare level control, I may not use it anyway. I am not wild about the three knobs so I may cough up the big bucks for a Goldpoint. What value would I want? 100K audio?
Solder on,
George
As far as delivery of the board is concerned I believe that it was pushing three weeks from the date of order. I get boards from Elliott Sound Products quicker than that and ESP is in Sydney, Australia and I am in Pennsylvania, USA.
I still need an answer on where to insert the level control? For some reason I think that it would go before the input.
Assuming that I eventually get the GlassWare level control, I may not use it anyway. I am not wild about the three knobs so I may cough up the big bucks for a Goldpoint. What value would I want? 100K audio?
Solder on,
George
I found a schematic of the current All in One power supply on the TubeCAD blog. I am going to use a 200V, .13A (no center tap) transformer (AnTek) which should give me about 281V raw DC. I am guessing that the transformer is more than adequate to run four 12AU7's. I don't know what R13 - R16 are for? They are 10R.
I am shooting for 250V plate voltage so I am guessing that I need to juggle R17, R12A, and R12B to get 250V?
R17 could be a choke. What advantage, if any, would that be?
Solder on,
George
new question
I've got the boards done and procured most of the parts so it is time to do the chassis layout and start drilling and milling. I would like to have two pairs of output jacks, one pair for a future subwoofer. How would I wire that? Just parallel the two pairs of output jacks?
Thanks in advanced to anyone who replies.
Solder on,
George
I've got the boards done and procured most of the parts so it is time to do the chassis layout and start drilling and milling. I would like to have two pairs of output jacks, one pair for a future subwoofer. How would I wire that? Just parallel the two pairs of output jacks?
Thanks in advanced to anyone who replies.
Solder on,
George
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