No Schematic?? WTF
I was really looking forward to the schematic for this unit. Randy, please keep us posted on the outcome of your negotiations with the publisher of the user manual.
I have put off the following questions hoping the schematic would provide insight.
Vinnie, how did you determine which Caps to swap out?
Compared to Bobwire's mods your increase in capacitance seems very moderate. I understand why this may be so fo the switching PS, but why such moderation on the audio boards?
What would benefit if any would be gained from increasing capacitance?
I have used small panasonic polypropylene caps (0.1 and 0.01) on electrolytics caps near opamps and I have found that there is a speed (snap on snares etc) that is lacking in the 3590 mods.
Would bypass caps be beneficial on the Panasonic caps?
If so which caps?
I have not received the ICs from TI yet to try the blackgate and the IC portion of the Vinnie mod, yet. I am currnetly using Dayton caps for the Swenson mods for the output.
Any insights you could provide would be appreciated.
I was really looking forward to the schematic for this unit. Randy, please keep us posted on the outcome of your negotiations with the publisher of the user manual.
I have put off the following questions hoping the schematic would provide insight.
Vinnie, how did you determine which Caps to swap out?
Compared to Bobwire's mods your increase in capacitance seems very moderate. I understand why this may be so fo the switching PS, but why such moderation on the audio boards?
What would benefit if any would be gained from increasing capacitance?
I have used small panasonic polypropylene caps (0.1 and 0.01) on electrolytics caps near opamps and I have found that there is a speed (snap on snares etc) that is lacking in the 3590 mods.
Would bypass caps be beneficial on the Panasonic caps?
If so which caps?
I have not received the ICs from TI yet to try the blackgate and the IC portion of the Vinnie mod, yet. I am currnetly using Dayton caps for the Swenson mods for the output.
Any insights you could provide would be appreciated.
Re: No Schematic?? WTF
Dave,
I swapped out the electrolytics used for the power supply rails (on the power supply unit and the audio PCB). I don't believe that putting in huge increases in capacitance is the way to go
You mainly want quality, not quantity (ie, low ESR is better than just large capacitance). You could use even larger sized caps than I did, but I'm not sure if it is worth it because I don't think you really need it. Also, if you use a ton of capacitance, you will get large in-rush current surges upon power up, and this can lead to damage to the diodes and possibly other parts of the power supply.
>>and I have found that there is a speed (snap on snares etc) that is lacking in the 3590 mods.
Well you haven't done all the mods that I have done including changing the opamp and signal caps with the black gates. You might feel differently after you try them. BTW, what is your Tosh driving (what preamp) ?
>>Would bypass caps be beneficial on the Panasonic caps?
There are already bypass caps (surface mount type) across all the electrolytics. I don't think extra bypass caps are necessary, but feel free to experiment.
>>I am currnetly using Dayton caps for the Swenson mods for the output.
Try other brands like Auricaps. You'll know when you find the ones with the best synergy with your system. What value are you using? Are you also using the 300pF caps from the outputs to GND?
-Vinnie
Davet said:
Dave,
I swapped out the electrolytics used for the power supply rails (on the power supply unit and the audio PCB). I don't believe that putting in huge increases in capacitance is the way to go
You mainly want quality, not quantity (ie, low ESR is better than just large capacitance). You could use even larger sized caps than I did, but I'm not sure if it is worth it because I don't think you really need it. Also, if you use a ton of capacitance, you will get large in-rush current surges upon power up, and this can lead to damage to the diodes and possibly other parts of the power supply.
>>and I have found that there is a speed (snap on snares etc) that is lacking in the 3590 mods.
Well you haven't done all the mods that I have done including changing the opamp and signal caps with the black gates. You might feel differently after you try them. BTW, what is your Tosh driving (what preamp) ?
>>Would bypass caps be beneficial on the Panasonic caps?
There are already bypass caps (surface mount type) across all the electrolytics. I don't think extra bypass caps are necessary, but feel free to experiment.
>>I am currnetly using Dayton caps for the Swenson mods for the output.
Try other brands like Auricaps. You'll know when you find the ones with the best synergy with your system. What value are you using? Are you also using the 300pF caps from the outputs to GND?
-Vinnie
.Vinnie mod cap quality
Vinnie,
Thanks for the response. I have my Tosh feeding a heavily tweaked Bottlehead Foreplay tube preamp. For the moment, I am using Dayton 0.47 MFD coupling caps with 390 pf ceramic caps connecting to ground. I have a set of Auricaps on order, as well as, opamps from TI. I already have the Blackgates, and I am awaiting the extra parts to complete the Vinnie mod.
The overall increase in bass, and broadened and deepened soundstage I attribute to the lower ESR and the increase in capacitance.
I am thoroughly enjoying modding the 3590 and looking forward to completing the rest of the mod. I have yet to work on dampening and isolation. I will let that wait until after I complete the electronic mods.
I also plan to build a copper cage for the PS and to place copper shields on all the audio board ICs. The IC shields will all be star grounded. This may be over kill, but on my tweaked Sony CDP IC shielding seemed to have lowered the noise floor.
Thanks for all the guidance you and John have provided. It has been a great ride so far!
Vinnie,
Thanks for the response. I have my Tosh feeding a heavily tweaked Bottlehead Foreplay tube preamp. For the moment, I am using Dayton 0.47 MFD coupling caps with 390 pf ceramic caps connecting to ground. I have a set of Auricaps on order, as well as, opamps from TI. I already have the Blackgates, and I am awaiting the extra parts to complete the Vinnie mod.
The overall increase in bass, and broadened and deepened soundstage I attribute to the lower ESR and the increase in capacitance.
I am thoroughly enjoying modding the 3590 and looking forward to completing the rest of the mod. I have yet to work on dampening and isolation. I will let that wait until after I complete the electronic mods.
I also plan to build a copper cage for the PS and to place copper shields on all the audio board ICs. The IC shields will all be star grounded. This may be over kill, but on my tweaked Sony CDP IC shielding seemed to have lowered the noise floor.
Thanks for all the guidance you and John have provided. It has been a great ride so far!
Swenson Mod'ed SD3960
All,
This is my Swenson Mod'ed SD3960. I though I would post a picture because I soldered pins to where the original coupling caps were - makes for a very clean mod and people may find useful. Using pins allows very easy connection of the new coupling caps from the front side of the pcb as well as ability to experiment. Pins are snipped from a standard single row pin strip (3 pins) with the center pin pulled out. Fit where the caps were perfectly. Also, absolutely agree with what people are saying about the sonics of the SD3960 - sounds way better than it has a right too
-ALBQ
All,
This is my Swenson Mod'ed SD3960. I though I would post a picture because I soldered pins to where the original coupling caps were - makes for a very clean mod and people may find useful. Using pins allows very easy connection of the new coupling caps from the front side of the pcb as well as ability to experiment. Pins are snipped from a standard single row pin strip (3 pins) with the center pin pulled out. Fit where the caps were perfectly. Also, absolutely agree with what people are saying about the sonics of the SD3960 - sounds way better than it has a right too
-ALBQ
Attachments
well, today I finished my initial (and probably ony) mods to my spanking new Toshiba 3950. Because of the low cost of the unit and uncertain longevity I decided to go with the 'less is more' approach (a la Swensen).
Instead of removing the DAC output coupling capacitors (C910 & C912) and tapping in wires that ran outside the unit to large (physically) .47 uF caps that were attached to 'hanging RCA jacks, I decided to make internal mods that were not so homely.
First I removed C910 & C912 to disconnect the DAC from the final digital filter and OpAmp (as did Swenson). Instead of removing the circuit board (as Swenson did) I decided to make the entire mod above the board. The main reason is that the flat strap wiring harnesses are built so flimsily that I decided that taking them apart may cause permanent problems.
I removed the capacitor by grasping with flat nosed pliers and twisting them in a constant circular motion until they snapped off. The first one I tried to snip with dikes but the left over lead was a little short. By experimentation I found the twisting left enough lead to work with.
I used the same removal method to take outC918 and C20 to disconnect the OpAmp from the RCA jacks.
There are two small yellow caps next to the RCA jacks that go between the RCA jacks and ground. Another DIY post claimed by others the removal further enhance the output signal of the Swenson mod, so I performed the twisting removal of those. Starting to be fun by now!
In the (6) capacitor removal, what was left was their leads flat against the circuit board and touching each other at the center. I used a small flat blade screwdriver to pluck the remainig wire away from the board for tinning.
The inner leads of the two small yellow capacitors connect to the signal lead of the RCA jacks so I decided to take advantage of them for my added capacitor connections.
The remaining proceedure is simply to tin the capacitors, and the upright short ckt bd leads and attatch new coupling capacitors.
I ordered .68 Uf poly German made ERO's and the man on Ebay sent a couple of extra samples of ERO .47Uf caps. The .47's were somewhat smaller than the .68's so I decided to use them (they are the size Swnson used anyway). Even tho I had previously figured the .68's were more suited to my Technics SU8600's preamp in, I think the size difference justified using the .47's.
I installed the new ERO's to the short leads left from C910 & C912 and the RCA jack side of the leads left from removal od the small yellow caps.
Because the ckt bd leads were so short (about 3/16") I could not make a mechanical connection prior to soldering and had to rely on a good solder job. This is difficult with two hands and help would be advised to make sure there is no movement while the solder sets.
That's it! Initial sound trials were very satisfying. I have no good reference to what the stock 3950's great sound was like, but It seemed to me that there was a noticeable improvement. I am a opera fanatic so I put on some standards like Rene Fleming and others that I had been listening to for years and I do love what the little unit does for the.....especially when they hit their highs.
sorry for the long wind and no pic's. Every time I try to upload a pic I use way two many bits of info and get rejected. Chuck
--------------------------------------------------------------------------------
Last edited by AK 47 : Yesterday at 08:39 PM.
Instead of removing the DAC output coupling capacitors (C910 & C912) and tapping in wires that ran outside the unit to large (physically) .47 uF caps that were attached to 'hanging RCA jacks, I decided to make internal mods that were not so homely.
First I removed C910 & C912 to disconnect the DAC from the final digital filter and OpAmp (as did Swenson). Instead of removing the circuit board (as Swenson did) I decided to make the entire mod above the board. The main reason is that the flat strap wiring harnesses are built so flimsily that I decided that taking them apart may cause permanent problems.
I removed the capacitor by grasping with flat nosed pliers and twisting them in a constant circular motion until they snapped off. The first one I tried to snip with dikes but the left over lead was a little short. By experimentation I found the twisting left enough lead to work with.
I used the same removal method to take outC918 and C20 to disconnect the OpAmp from the RCA jacks.
There are two small yellow caps next to the RCA jacks that go between the RCA jacks and ground. Another DIY post claimed by others the removal further enhance the output signal of the Swenson mod, so I performed the twisting removal of those. Starting to be fun by now!
In the (6) capacitor removal, what was left was their leads flat against the circuit board and touching each other at the center. I used a small flat blade screwdriver to pluck the remainig wire away from the board for tinning.
The inner leads of the two small yellow capacitors connect to the signal lead of the RCA jacks so I decided to take advantage of them for my added capacitor connections.
The remaining proceedure is simply to tin the capacitors, and the upright short ckt bd leads and attatch new coupling capacitors.
I ordered .68 Uf poly German made ERO's and the man on Ebay sent a couple of extra samples of ERO .47Uf caps. The .47's were somewhat smaller than the .68's so I decided to use them (they are the size Swnson used anyway). Even tho I had previously figured the .68's were more suited to my Technics SU8600's preamp in, I think the size difference justified using the .47's.
I installed the new ERO's to the short leads left from C910 & C912 and the RCA jack side of the leads left from removal od the small yellow caps.
Because the ckt bd leads were so short (about 3/16") I could not make a mechanical connection prior to soldering and had to rely on a good solder job. This is difficult with two hands and help would be advised to make sure there is no movement while the solder sets.
That's it! Initial sound trials were very satisfying. I have no good reference to what the stock 3950's great sound was like, but It seemed to me that there was a noticeable improvement. I am a opera fanatic so I put on some standards like Rene Fleming and others that I had been listening to for years and I do love what the little unit does for the.....especially when they hit their highs.
sorry for the long wind and no pic's. Every time I try to upload a pic I use way two many bits of info and get rejected. Chuck
--------------------------------------------------------------------------------
Last edited by AK 47 : Yesterday at 08:39 PM.
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