I have 4 of the src2496... I have a mod process that works well and sounds amazing!
1) replace first opamp after dac with lm4562, bias to class a with 2.2 k resistors
2) remove 2'd and 3d opamp after dac - I simply cut them off the board
3) solder 12" rca cable hot wire to + of c25 and c26, ground to common audio ground on PCB
-this leaves only a few millivolts of DC offset on output - I use a tube pre so no issue. If you must have no DC whatsoever then a 1uf vitQ bypassed with .22uf 600v Russion teflon sounds quite nice as well but slightly less detailed.
4) solder 3 pairs of short wire leads to pcb where power supply feeds it. Add 3 1800uf 35v Panasonic FC to each rail bypassed with 1uf vitQ, .22uf russian teflon and .01uf GE polyprop on main pcb where wires attach.
5) Coat entire underside of top lid and sides with hot melt glue for damping
7) replace iec input jack with filtered iec jack
7) listen and **** pants
I remove one of the xlr output connectors for a path to route the rca cables. I use hotglue to fill the hole and hold the cables in place. I use "premium" gold connector Radio Shack rca cables for the interconnect. Being only 12 - 15" long hopefully lowers cable losses and the direct solder connection on the src is better than an rca plug. The filtered iec jack actually made the unit sound different in my application - a "softer" sound would be the best way I could describe it.
Once you get past the 100' wide stereo image the next most noticable quality is the extremely tight bass, I assume due to the massive increase of power supply capacitance. Deeper and much much tighter. Tons of midrange detail and natural timbre and texture. Treble sounds more natural as well. Watching movies and tv, the ambient sounds and distant dialog are shocking. Would love to hear with akm4396!
1) replace first opamp after dac with lm4562, bias to class a with 2.2 k resistors
2) remove 2'd and 3d opamp after dac - I simply cut them off the board
3) solder 12" rca cable hot wire to + of c25 and c26, ground to common audio ground on PCB
-this leaves only a few millivolts of DC offset on output - I use a tube pre so no issue. If you must have no DC whatsoever then a 1uf vitQ bypassed with .22uf 600v Russion teflon sounds quite nice as well but slightly less detailed.
4) solder 3 pairs of short wire leads to pcb where power supply feeds it. Add 3 1800uf 35v Panasonic FC to each rail bypassed with 1uf vitQ, .22uf russian teflon and .01uf GE polyprop on main pcb where wires attach.
5) Coat entire underside of top lid and sides with hot melt glue for damping
7) replace iec input jack with filtered iec jack
7) listen and **** pants
I remove one of the xlr output connectors for a path to route the rca cables. I use hotglue to fill the hole and hold the cables in place. I use "premium" gold connector Radio Shack rca cables for the interconnect. Being only 12 - 15" long hopefully lowers cable losses and the direct solder connection on the src is better than an rca plug. The filtered iec jack actually made the unit sound different in my application - a "softer" sound would be the best way I could describe it.
Once you get past the 100' wide stereo image the next most noticable quality is the extremely tight bass, I assume due to the massive increase of power supply capacitance. Deeper and much much tighter. Tons of midrange detail and natural timbre and texture. Treble sounds more natural as well. Watching movies and tv, the ambient sounds and distant dialog are shocking. Would love to hear with akm4396!
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highest level of modification with tube.. improve based on Dr.Lampizator..
Check my high end setup!
lol. the picture of modding is not mine. currently my dac is still under progress to a to a highest level of modification as possible. instead of analogue stage, digital input will be tweaked with rare blackgate caps.
First main power is using Phillips Ultrafast diode for dc rectification. A new dedicated 60va transformer for digital and CLOCK . As well as the digital power, a higher capacitance of blackgate standard 16v/4700uf will be replace too. then replace dirty 7805 with lm2940 with blackgate FK 16v/470uf smoothing. some digital filter or other caps will be replaced with blackgate FK 16/47uf instead of ciplak 25v/10uf. hehe..... cool huh..
For the digital signal input, extra dedicated SwitchCraft RCA socket for coaxial. Bypassing the dirty multiplexer where significantly improve the quality of digital signal from Transport.
Digital section last stage improvement mod, replace the clcok with LCaudio LCLOCK XO3 because it has two output of the same frequency. Where my transport has the same too!!! this would compensate the greatest advantage to sound accuracy. Next, LCLOCK became the house clock in entire digital transmission. the clock with dedicated power supply CLCLC design, same Hexfred 19ns(trr) dc rectification with Nippon chemicon KMH 35v/8200uf caps. Moreover, the clock itself will be fully added blackgate decoupling capacitor.
For the analogue Output, 50va transformer for tube power. same, hexfred for dc rectification. tube power filtering with CLC design, Obbligato Film Oil cap for front and back stage then Nippon chemicon electrolitic KMH for middle stage. resistor for tube circuit will be using Kiwame although my fren told me it sucks.. anyway let see and listen then only decide wat to change again loh.. Legendary Russian OTK grade 6H6P for the tube. then output coupling capacitor with Mundorf Silver oil 2.2uf till special ETi RCA gold plated socket.
Picture of my mods will be posted when the dac is done.. and i will keep u update.. thanks for ur interest.
Check my high end setup!
lol. the picture of modding is not mine. currently my dac is still under progress to a to a highest level of modification as possible. instead of analogue stage, digital input will be tweaked with rare blackgate caps.
First main power is using Phillips Ultrafast diode for dc rectification. A new dedicated 60va transformer for digital and CLOCK . As well as the digital power, a higher capacitance of blackgate standard 16v/4700uf will be replace too. then replace dirty 7805 with lm2940 with blackgate FK 16v/470uf smoothing. some digital filter or other caps will be replaced with blackgate FK 16/47uf instead of ciplak 25v/10uf. hehe..... cool huh..
For the digital signal input, extra dedicated SwitchCraft RCA socket for coaxial. Bypassing the dirty multiplexer where significantly improve the quality of digital signal from Transport.
Digital section last stage improvement mod, replace the clcok with LCaudio LCLOCK XO3 because it has two output of the same frequency. Where my transport has the same too!!! this would compensate the greatest advantage to sound accuracy. Next, LCLOCK became the house clock in entire digital transmission. the clock with dedicated power supply CLCLC design, same Hexfred 19ns(trr) dc rectification with Nippon chemicon KMH 35v/8200uf caps. Moreover, the clock itself will be fully added blackgate decoupling capacitor.
For the analogue Output, 50va transformer for tube power. same, hexfred for dc rectification. tube power filtering with CLC design, Obbligato Film Oil cap for front and back stage then Nippon chemicon electrolitic KMH for middle stage. resistor for tube circuit will be using Kiwame although my fren told me it sucks.. anyway let see and listen then only decide wat to change again loh.. Legendary Russian OTK grade 6H6P for the tube. then output coupling capacitor with Mundorf Silver oil 2.2uf till special ETi RCA gold plated socket.
Picture of my mods will be posted when the dac is done.. and i will keep u update.. thanks for ur interest.
My SRC2496 has developed a fault ... one analogue output channel has become severely attenuated. Took the back off, can't see anything obviously wrong. It is the right channel near the voltage regulators that get rather hot. I can do easy soldering but my electronics knowledge is not great ... any ideas?
Tim
Tim
hmm..
check analog part from dac output.. check whether short circuit or not. if otherwise ... do this to tube output..
check analog part from dac output.. check whether short circuit or not. if otherwise ... do this to tube output..
lol. the picture of modding is not mine. currently my dac is still under progress to a to a highest level of modification as possible. instead of analogue stage, digital input will be tweaked with rare blackgate caps.
Do I understand correctly that you're terminating one output of the DAC with a 300k load and the other terminal with (roughly) a 200R load? If so, can you give some insight into that, uhhh, unusual choice?
Anything lower than 600 ohm AC impedance or 1k DC impedance on those DACs will raise non-linearity.
That said, Stuart, not being a tube geek, but it seems its even worse than 330 ohms I think, that cathode looks like a short almost to that poor DAC. Or is that accounted for in the 200 ohms you quoted?
jd
That said, Stuart, not being a tube geek, but it seems its even worse than 330 ohms I think, that cathode looks like a short almost to that poor DAC. Or is that accounted for in the 200 ohms you quoted?
jd
It will be the cathode resistor in parallel with the input impedance at the cathode. The cathode impedance looks like the plate resistance plus load resistance divided by (mu + 1). I was too lazy to look up the numbers for the tube he gave, but we can estimate. Throwing in some likely numbers, we have a 10k load, let's guess a 5k plate resistance and a mu of 20. That's 750 ohms, paralleling the 330R.
My question on tube output stages for voltage DACs (like the AKM) is:
What is there to be gained?
Do you need voltage gain? The AKM in the Behringers outputs 1.75V RMS at full scale. That's plenty for me. But if you need more, I understand. How much more?
Do you need current gain? That would sure be handy, but is the tube really supplying more current? As far as I can measure, the AKM as an output impedance of ~100 ohms. So is a tube stage really giving any current gain?
Also these chips are balanced out. They are designed to work best when you use the differential signal, not just one side. Is using just one side better? Different?
I don't meant to be difficult here, but I think these are legitimate questions for a voltage DAC like the AKM. What benefits does the tube stage bring?
What is there to be gained?
Do you need voltage gain? The AKM in the Behringers outputs 1.75V RMS at full scale. That's plenty for me. But if you need more, I understand. How much more?
Do you need current gain? That would sure be handy, but is the tube really supplying more current? As far as I can measure, the AKM as an output impedance of ~100 ohms. So is a tube stage really giving any current gain?
Also these chips are balanced out. They are designed to work best when you use the differential signal, not just one side. Is using just one side better? Different?
I don't meant to be difficult here, but I think these are legitimate questions for a voltage DAC like the AKM. What benefits does the tube stage bring?
i have done my DAC with tube out put
tube out put gives u analog sound..
check this.. and hope to see ur comment .
i am a malaysian, in malaysia forum they all trust only branded stuff.
this is too bad.. this shows that their listening experience is too low or limited..
i hope ur all will reply in my malaysia post and tell ur country origin too.
so they can know there are lots of pro among the world..
MY FULLY MODDED BEHRINGER SRC2496 WITH TUBEOUT AND CLOCK IN MALAYSIA
tube out put gives u analog sound..
check this.. and hope to see ur comment .
i am a malaysian, in malaysia forum they all trust only branded stuff.
this is too bad.. this shows that their listening experience is too low or limited..
i hope ur all will reply in my malaysia post and tell ur country origin too.
so they can know there are lots of pro among the world..
An externally hosted image should be here but it was not working when we last tested it.
MY FULLY MODDED BEHRINGER SRC2496 WITH TUBEOUT AND CLOCK IN MALAYSIA
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