Hello everyone, i have recently just built a SB4000 next generation Gssl and i have got an SRPP to use an input drive stage for teh unit (university project)
however, i now have all the parts in front of me and i have come to a stand still.
Here is the advert for what i have including schematic.
STEREO 6DJ8 ECC88 6922 E88CC SRPP TUBE PREAMPLIFIER KIT on eBay (end time 04-Apr-11 16:30:30 BST)
I was advised to get a dual gang 100k log pot and connect the input from xlr on the sb4000 to one leg of the dual gang pot,
wiper to pin 2 of the tube, and other pot leg to ground.
However there is + and - wires for the xlr's and only one leg to connect to each side of the pot.???
Do i just connect the + wire to the pot leg and leave the - wire out???
And above all will this work as a volume drive for the unit??
Any suggestions or help will be very much appreciated
Thanks again
Shea
😱
however, i now have all the parts in front of me and i have come to a stand still.
Here is the advert for what i have including schematic.
STEREO 6DJ8 ECC88 6922 E88CC SRPP TUBE PREAMPLIFIER KIT on eBay (end time 04-Apr-11 16:30:30 BST)
I was advised to get a dual gang 100k log pot and connect the input from xlr on the sb4000 to one leg of the dual gang pot,
wiper to pin 2 of the tube, and other pot leg to ground.
However there is + and - wires for the xlr's and only one leg to connect to each side of the pot.???
Do i just connect the + wire to the pot leg and leave the - wire out???
And above all will this work as a volume drive for the unit??
Any suggestions or help will be very much appreciated
Thanks again
Shea
😱
If J3 is your XLR, then it does not appear to be wired correctly; which would explain why R6 is shorted and also why pin 2 of U2 is grounded. With XLR's: pin 1 is ground, pin 2 is hot , and pin 3 is return.
The kit on eBay uses a 6N1 not the 6N2.. I have no idea what a SB4000 next generation GSSL might be either - is it a power amp or a source? I'm assuming it is an amplifier in which case you really would be better off driving it with a balanced device.
Note that there are no XLR connectors on this board, just barrier strips to which you can wire your inputs, outputs, and power supply connections.
Note that if you really need balanced drive you could use two of these - one per channel to drive an amp, but in that case you would still need a balanced source, and the volume control would have to be wired in a shunt configuration across the inputs.
Note that there are no XLR connectors on this board, just barrier strips to which you can wire your inputs, outputs, and power supply connections.
Note that if you really need balanced drive you could use two of these - one per channel to drive an amp, but in that case you would still need a balanced source, and the volume control would have to be wired in a shunt configuration across the inputs.
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Thanks for the replys guys!
The sb4000 is a stereo compressor, it works really well wen driven.
The unit is a balanced unit and the srpp is not so it would make the input of the sb4000 unbalanced.
Im trying to see if this hot pin only connection would work
The sb4000 is a stereo compressor, it works really well wen driven.
The unit is a balanced unit and the srpp is not so it would make the input of the sb4000 unbalanced.
Im trying to see if this hot pin only connection would work
Those little PCBs that allow B9A tubes to be mounted at right angles are interesting. I have seem something similar in the Vintec mega tube console. I notice the kit ones use regular PCB tube sockets but Vintec appears to solder the tubes directly to the PCB and then plug in the PCB.
Apart from the convenience of orientation, is there any real advantage to this method of mounting?
Cheers
Ian
Apart from the convenience of orientation, is there any real advantage to this method of mounting?
Cheers
Ian
Best I can figure it just allows a really low profile for mounting in a 1U high rack chassis or similar.. In some ways it may be less optimum due to additional solder joints, and somewhat longer signal path lengths. Certainly not a problem thermally speaking with small signal tubes with very limited dissipation, but higher power types are harder to cool and often have restrictions on their horizontal orientations as well. (Things like certain pins having to be placed on the vertical plane, etc.) I would guess in this particular instance it is more for cool factor than anything else and I actually do like the idea on some level.
For some reason I too find the idea quite attractive. I thought there might possibly be some microphony advantages due to the lower coupling of the tube to the main PCB but I expect that is just wishful thinking.
It is certainly interesting from a packaging point of view since it provides at least one more degree of freedom. It does not seem to be very common and I wondered if any DIYers had tried it?
Cheers
Ian
One of the reasons i got this one was for its horizontal layout, saves space vertically plus as i am soldering to pin 2 of the tube socket, its easier to get to for a newb like me.
Has anyone got any more opinions on my connections for the 100k pot for volume on this thing?
Has anyone got any more opinions on my connections for the 100k pot for volume on this thing?
If you are driving a balanced input from an unbalanced source then you connect XLR + to signal, and XLR - to ground. If you want to put a volume pot in, then check the input impedance of your unit, and the stated load impedance of the SRPP stage.
Why did you choose SRPP? I doubt if it is the best option for a preamp, even though the Chinese seem to love it.
The heater and HT supplies look a bit marginal to me. Also, there is no DC isolation on the input, and no DC grounding on the output. I would treat this, as is often the case for Chinese stuff on ebay, as a starting point for modifications - not a tried and tested reliable design.
Finally, when you write up this work, don't forget to mention the help you received here.
Why did you choose SRPP? I doubt if it is the best option for a preamp, even though the Chinese seem to love it.
The heater and HT supplies look a bit marginal to me. Also, there is no DC isolation on the input, and no DC grounding on the output. I would treat this, as is often the case for Chinese stuff on ebay, as a starting point for modifications - not a tried and tested reliable design.
Finally, when you write up this work, don't forget to mention the help you received here.
Thank you! And of course i will be quoting from this site! Really appreciate the help i am getting from you guys
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