Since we have no takers I will ask a different question. With regard to the Underwood Hifi mods they describe replacing the input and output buffers with Dexa Opamps. I am curious what people think the value is of installing opamps which are even better than Dexa in these postions. Burson, Sonic Imagery, Sparkos for example.
W4S STP-SE DIY mods
Greetings,
I've got my STP-SE inhouse and researching my upgrade mods. I understand both Underwood and W4S sell mods as a service but I would like to keep costs down and exercise my soldering iron.
Does anyone have specifics on values/locations for updating the volume ladder resistors, diodes, and inductors that would be awesome.
I believe I have details around the PS caps, voltage regs and opamp chips.
Anyone have specific recommendations for parts to swap vs leave as is? Any specific pitfalls or gotchas I should be aware of?
Thanks much,
I've got my STP-SE inhouse and researching my upgrade mods. I understand both Underwood and W4S sell mods as a service but I would like to keep costs down and exercise my soldering iron.
Does anyone have specifics on values/locations for updating the volume ladder resistors, diodes, and inductors that would be awesome.
I believe I have details around the PS caps, voltage regs and opamp chips.
Anyone have specific recommendations for parts to swap vs leave as is? Any specific pitfalls or gotchas I should be aware of?
Thanks much,
Showing 5 responses by vfrpilot
Very interesting and enlightening feedback Auxinput. Much appreciated. I am surprised to see that you would reference a monolithic opamp as being more transparent than a discreet one much less the SOTA ones. STP-SE contains two input buffers and one output buffer. any idea the role and relative importance of the two input buffers? one SE and the second for Balanced? Two stages? |
Your right. i mixed it up. :-) http://www.underwoodhifi.com/modifications/wyred-4-sound "We add 1 DEXA Technologies “discrete” DUAL op amp module to the input buffer. Two additional DEXA Technologies “discrete” DUAL op amp modules. One for each output buffer." thanks again for your recommendations, they seem inline with my thinking and research. sounds like you have listened extensively to what i have only read and thought about. Cheers! |
Quote: "I have also had benefits when soldering a 47uf Nichicon Muse + 0.1uf to the +/- power pins of an opamp." Question: would i add this to each opamp individually or just to the dual DIP8 pins on the adapter? It seems obvious that it would be a single .1uf mkp cap across the adapters pins itself and not each opamp but just checking. |
"One theory would be that you mixed it up and there is only one input buffer with two output buffers. The one input buffer would only be used to create the "inverted" balanced signal when a single-ended RCA input is used. Then it goes to the discrete FET stage, which should be fully balanced/differential. Then there are two output buffers for both the normal and inverted signals of the XLR connection." So upgrading the input buffer would only improve the sound of the RCA inputs and have no affect on the balanced input signals? |