I'm thinking about selling my modified Music Hall 25.2 DAC to finance upcoming projects. I've been listening to it for a little over a year now. It has got a very sweet sound with plenty of punch thanks to the modifications to the power supply and the beefy decoupling caps.
Here are some of the main features of the DAC:
And here's a list of modifications that I've made to the DAC:
Some reviews of the (unmodified) DAC can be found at 6moons audio reviews: 32Ohm Audio Review Series N°.1 and Music Hall dac25.2 D/A processor | Stereophile.com and also https://system.netsuite.com/core/me...a2c9b63281&_xt=.pdf &addrcountry=US&gc=clear (pdf!).
The DAC comes with the original packaging. I'll ship worldwide from Austria/Europe at cost.
If you are interested in this versatile D/A-converter, make me an offer per PM. Comments, praise, criticism and questions are always welcome.
Here are some of the main features of the DAC:
- Electro-Harmonix 6922 (ECC88, 6DJ8) tube single-ended (RCA) output
- solid-state differential balanced output
- TI PCM 1796 24bit/192kHz DAC
- TI SRC 4192 asynchronous sample rate converter
- user selectable 96kHz or 192kHz upsampling
- asynchronous reclocking and anti jitter control system
- 8 x oversampling digital filter
- 4 digital inputs: coax (s/pdif), optical Toslink, XLR (AES/EBU), or USB via Burr Brown PCM2704
- single ended RCA and balanced XLR outputs
- headphone output with adjustable analog volume control
- 110v/220v voltage selectable transformer
And here's a list of modifications that I've made to the DAC:
- twisted all cables for minimized stray fields
- changed all resistors in the I/V-stage to PRP Precision metalfilm resistors
- changed all film capacitors in the I/V-stage to Styroflex/FKP film types
- changed all capacitors of the DAC-chip to Panasonic OS-CON Aluminum-Polymer-Capacitors
- changed all decoupling caps of the opamps to 470uF/35 Panasonic FR (ultra low impedance) electrolytic caps
- changed all voltage regulators (instead of common 7815/7915 and 7805 regulators) for analog and digital circuits to precision-LDO regulators
- two DIYINHK 1.0uV Ultralow noise DAC power supply LT3042 regulators 5.0V 800mA
- DIYINHK 4.17uV Ultralow noise DAC power supply TPS7A4700 regulator +-15V 1A
- LINEAR Technology LT1963 SOT-223 LDO regulator 3.3V 1.5A
- changed all opamps in the I/V-stage to TI LM4562MA SOIC8 on DIP8 adapters with 0.1uF Wima MKP4 decoupling capacitors directly at the chip
- changed all filter capacitors in the tube heater circuit (Panasonic FR) and the high voltage supply (ELNA)
- changed voltage reference in high voltage supply to low noise Zener diodes with 0.1uF Wima MKP4 filter capacitor
- changed resistors in the tube buffer stage to high power PRP Precision metalfilm resistors and the gate stopper resistors to Ohmite carbon composite resistors
- changed all coupling capacitors in the tube buffer stage to Mundorf MCap EVO Aluminum 3.3uF 450V
- changed the decoupling capacitors for the headphone amplifier to 100uF/35V Panasonic FR
- changed the input and output coupling capacitors of the headphone amplifier to Panasonic ECW 2.2uF 450V Polypropylen and Nichicon 100uF 50V KZ Muse
- changed the RCA/Phono Jack to gold plated Neutrik NYS367
- changed the front panel LEDs from blue to warm white LEDs with adjusted (non-blinding) brightness
Some reviews of the (unmodified) DAC can be found at 6moons audio reviews: 32Ohm Audio Review Series N°.1 and Music Hall dac25.2 D/A processor | Stereophile.com and also https://system.netsuite.com/core/me...a2c9b63281&_xt=.pdf &addrcountry=US&gc=clear (pdf!).
The DAC comes with the original packaging. I'll ship worldwide from Austria/Europe at cost.
If you are interested in this versatile D/A-converter, make me an offer per PM. Comments, praise, criticism and questions are always welcome.
Attachments
I have to say, you did a marvelous tasteful tune to this. Very clean work as well. I am thinking you will miss this once released 😉 GLWS
BUMP
In the course of this bump I'd like to add some info on the raw materials for the mods:
For just the parts added to the DAC, I've spent around 60USD for the +-15V reg, 2* 50USD for the +5V regs, 30USD for the Mundorf Mcaps, around 30USD for all the caps and another 20USD for the resistors, plus opamps (genuine LM4562MA sourced from Mouser), adapters, jacks, ultrafast diodes and so on.
Furthermore, I've looked up the shipping costs for shipping to the US, they should be around 40USD (with tracking and insurance) and shipping would take around 10 days.
Hope this helps, if anyone has any questions, feel free to ask here or drop me a PM!
In the course of this bump I'd like to add some info on the raw materials for the mods:
For just the parts added to the DAC, I've spent around 60USD for the +-15V reg, 2* 50USD for the +5V regs, 30USD for the Mundorf Mcaps, around 30USD for all the caps and another 20USD for the resistors, plus opamps (genuine LM4562MA sourced from Mouser), adapters, jacks, ultrafast diodes and so on.
Furthermore, I've looked up the shipping costs for shipping to the US, they should be around 40USD (with tracking and insurance) and shipping would take around 10 days.
Hope this helps, if anyone has any questions, feel free to ask here or drop me a PM!
- Status
- Not open for further replies.