I've got the same problem as ZirconiumZephyr. I built my VSPS point to point. I'm using a 570 ohm feedback resistor. the volume is very low, but the lows and highs are in proper proportion to each other. the problem is the same in both channels, which leads me to believe that it is not just a wiring error. My VSPS feeds a Pass B-1 buffer. I'm using a dual opamp with 14.5 volts +/- on pins 8 and 4. I've checked my solder joints 3 times. Could leaky caps in the feedback cause this? I checked them with a capacitance meter to match channels, and they tested fine.
What Protos wrote, with the following to add: the VSPS300 and VSPS Kit boards have very heavy copper planes that wick away the heat from the pad area, so you have to heat the pad with a hot iron for a few (perhaps as long as 10) seconds before heating the component lead and trying to make the join.
Good to use a relatively powerful iron for the job, of if you have a variable temperature model, turn it up a bit for those pads that are set in the ground plane.
Good to use a relatively powerful iron for the job, of if you have a variable temperature model, turn it up a bit for those pads that are set in the ground plane.
LM7812 and LM7912 are different. I do list them individually and labelled in the instruction parts list that ships with each VSPS kit. The parts list is intended as a "preflight checklist" so you tick off each and every part from the list as you find and identify them. As you go thorugh you are also supposed to note where each component goes on the board layout diagram printed opposite the checklist.
@decker: if you have power to the opamp and the opamp is the right way round (pin 4,8 is not pin 1,5) then the op amp is dead (it happens) or the the layout has the wrong connectivity. You can easily check the latter by measuring the AC voltage directly at the output pins of the opamp with music playing on the input. You should see 10's to 100's of mV peaks. If you get signal at the opamp output and not at the RCA output then the connectivity is messed up. If both are near zero the opamp is dead.
If the capacitors in the RIAA had failed the signal would not be equalized and would anyway appear at full volume at some frequency.
@decker: if you have power to the opamp and the opamp is the right way round (pin 4,8 is not pin 1,5) then the op amp is dead (it happens) or the the layout has the wrong connectivity. You can easily check the latter by measuring the AC voltage directly at the output pins of the opamp with music playing on the input. You should see 10's to 100's of mV peaks. If you get signal at the opamp output and not at the RCA output then the connectivity is messed up. If both are near zero the opamp is dead.
If the capacitors in the RIAA had failed the signal would not be equalized and would anyway appear at full volume at some frequency.
Phonoclone enclosure
Hello,
Just finished building Phonoclone in its final enclosure. I use cabinets from hifi2000, powersupply and amp separated as advised. One of the smaller cabinets seem to be perfect in size for 2 pcb's Phonoclone, little bigger than the 2 pcb's..
Powersupply consists of 2 oversized EI core transformers, diodes are BYV types.
Components of Phonoclone are all standard, no fancy audiophile parts (wouldn't fit anyway..). Sound is excellent! I use a Denon DL103 in a wooden body (Uwe body). R1 560ohms, R2=1K2.
Hello,
Just finished building Phonoclone in its final enclosure. I use cabinets from hifi2000, powersupply and amp separated as advised. One of the smaller cabinets seem to be perfect in size for 2 pcb's Phonoclone, little bigger than the 2 pcb's..
Powersupply consists of 2 oversized EI core transformers, diodes are BYV types.
Components of Phonoclone are all standard, no fancy audiophile parts (wouldn't fit anyway..). Sound is excellent! I use a Denon DL103 in a wooden body (Uwe body). R1 560ohms, R2=1K2.
Attachments
Good thing you decided to keep those EI trannies well away from the phonoclone circuit in a separate enclosure. Could have been problems otherwise.
Interesting arrangement of the lead wires. Not necessarily a brilliant idea to have the inputs and output wrapped around each other like that, as the strong output signal gets fed back into the inputs via capacitive coupling.
Interesting arrangement of the lead wires. Not necessarily a brilliant idea to have the inputs and output wrapped around each other like that, as the strong output signal gets fed back into the inputs via capacitive coupling.
Hum
My VSPS is now a Phonoclone. I made the changes. But now I have a problem: Hum! Shurely I'm not the first one who has this problem. When I disconnect the TT, the hum is the same. Is one of the Plugs (Binder 3-pol-connectors, symmetric wire) not plugged in to the pre-amp, there is more hum. The only thing I tried not yet ist to cut the grounding between TT - in and Phonoclone out.
My VSPS is now a Phonoclone. I made the changes. But now I have a problem: Hum! Shurely I'm not the first one who has this problem. When I disconnect the TT, the hum is the same. Is one of the Plugs (Binder 3-pol-connectors, symmetric wire) not plugged in to the pre-amp, there is more hum. The only thing I tried not yet ist to cut the grounding between TT - in and Phonoclone out.
o.k. I found the pages 128, 129... in this thread... Now I tried some things and the hum is now only a minimum on the right channel. The noise is now less, too. I tried two 12 V Batteries. That was the best. No hum!
The sound with my DL 103 modified by Heiko Wingender (stereolux Karlsruhe/Germany) and the PC is wonderful. Much better than with the VSPS.
My OP for input are two OPA 627(with adapter for dual op-amp), second stage ist the OPA 49720.
All ICs are lacquered with Ennemosers C37 varnish
The sound with my DL 103 modified by Heiko Wingender (stereolux Karlsruhe/Germany) and the PC is wonderful. Much better than with the VSPS.
My OP for input are two OPA 627(with adapter for dual op-amp), second stage ist the OPA 49720.
All ICs are lacquered with Ennemosers C37 varnish
