northpaw
Super Member
I’ve been looking around for an inexpensive DAC with optical, coax, and USB inputs and a headphone amp for use in a bedroom system. I’ve been intrigued by descriptions here (especially numerous posts by mjw21a) and elsewhere of boards with 8 paralleled recycled Philips TDA1387 DACs, which are made by some Chinese manufacturers from old sound cards.
These DAC boards have been around in various forms for at least 5 years, but the one I decided to try is a made-up device from an eBay seller that seems to be a relatively new variant, fitted with a “Solo” based circuit for the headphone amp, at $69. This one is listed as capable of delivering about 200mW into 32Ω (more than adequate for my small collection of earphones with similar impedance) and drops to 43mW at 600Ω. In contrast to the earlier devices I saw using the 8x 1387 DACs, this unit uses a higher voltage 24VDC power supply, presumably required by the headphone amp.
The physical quality of the DAC is quite good. Its an all-metal extruded Al case very similar to those used for some 2.5” computer drives. Overall it is pretty light, so it can be a bit tippy with 2 RCA cables on the outputs and another on coax input. The volume pot has a solid, viscous feel. The device comes supplied with a 24VDC 2amp power brick (although the eBay listing did not state that explicitly). Its light, so I am sure it is a switching type; I measured well below 1 mVAC of ripple on it.
Inside, it looks good as well. Of note is that what look like the coupling caps on the RCA outputs are axial Philips KO 22µF/40V, of a paler lavender color. I don’t believe these are current production, and could be recycled or NOS components. The other electrolytic caps inside include Nichicon PA, Rubycon PK, JCCON low ESR caps; these all appear to be 105° rated. There are two voltage regulators for 12V and 18V (STMicro 7812 and 7818) and three “shunt” linear regulators (Advanced Monolithic AMS1117). The one opamp I saw was an Analog Devices AD823 JFET input opamp. The digital receiver is a Cirrus Logic CS8416. All in all, some thought seems to have been given to the design and components used (i.e., not the cheapest possible parts).
Soldering quality looks very good, the board was clean of residual flux, and there is no glue on the caps
. The unit gets ever so slightly warm to the touch after playing for a few hours. The power brick stays cool to the touch.
Soundwise, I find this DAC very pleasing. Bass extension is very good (I was surprised by this as I thought I read that strong bass was not a forte for these DACs) and not muddy; shimmer on cymbals was delicately rendered. Violins sound clear and sweet where they should be sweet (e.g., The Lark Ascending by Vaughn Williams) and piercing where they should be so (e.g., the opening of Winter by Vivaldi), and without grit or harshness. Clarinets and trumpets similarly. Cellos and saxes had the deeper sonorous tones I expect to hear from them. Everything I played sounded engaging and non-fatiguing, always a good sign. Overall, for me, for relatively low-complexity music such as piano and violin sonatas, female vocals, etc., it provided as reasonable an approach to an in-the-room feel as I can expect from the system I tried it on (Nak SR-3A receiver and DCM TW1 speakers). I need to spend more time with it to evaluate how it renders more complex symphonic music over long passages, but it sounds promising so far. So does the headphone amp. Like the RCA outputs it is dead quiet (disclosure: my hearing tops out at 10kHz), and there is a fairly gentle response to the volume pot, allowing fine adjustment.
I am agnostic about the R2R vs DS debate (and have no desire to engage in that here); presently I have good examples of both (Adcom GDA-700 and Cambridge Audio DacMagic) and find them both very satisfying. It is early days yet for me with the 8x L1387Solo DAC (I’ve played it just for a couple of days), but at present I am finding myself happy to listen to any of these 3 DACs, and find them much more similar than different. Virtually all my non-radio listening is Red Book CDs. If my needs change in the future, the DacMagic and this L1387 (on its coax input) can accept higher resolution feeds, although I have no idea if they will be competitive in that arena with DACs based on more modern chips.
Quirks:
— The case is mislabeled for 15VDC power instead of 24VDC. Seems to be an oversight, or perhaps they have just recently been making the Solo amp version and have not yet produced an updated end plate; the case and its labeling are in fact identical to the L1387 DAC version with the JLH 1969-based amp circuit; you would not know which one it was without opening it up..
— For CD playing via coax input, I hear a slight pop (via the RCA outs to an amp) when the DAC unlocks/locks on the signal (e.g., when opening/closing the CD drawer). I haven’t yet fully explored if this is present for other players (I am using a Pioneer DVP-V7400 as a transport at present) or on other inputs, but I do not recall getting a pop when I hooked up a CCA to the optical input and initiated a radio station stream (listening with earphones in this case).
— The 4 LEDs (three for source indication, one for signal lock) are quite bright, a bit much for a dark room. At least they are red.
These DAC boards have been around in various forms for at least 5 years, but the one I decided to try is a made-up device from an eBay seller that seems to be a relatively new variant, fitted with a “Solo” based circuit for the headphone amp, at $69. This one is listed as capable of delivering about 200mW into 32Ω (more than adequate for my small collection of earphones with similar impedance) and drops to 43mW at 600Ω. In contrast to the earlier devices I saw using the 8x 1387 DACs, this unit uses a higher voltage 24VDC power supply, presumably required by the headphone amp.
The physical quality of the DAC is quite good. Its an all-metal extruded Al case very similar to those used for some 2.5” computer drives. Overall it is pretty light, so it can be a bit tippy with 2 RCA cables on the outputs and another on coax input. The volume pot has a solid, viscous feel. The device comes supplied with a 24VDC 2amp power brick (although the eBay listing did not state that explicitly). Its light, so I am sure it is a switching type; I measured well below 1 mVAC of ripple on it.
Inside, it looks good as well. Of note is that what look like the coupling caps on the RCA outputs are axial Philips KO 22µF/40V, of a paler lavender color. I don’t believe these are current production, and could be recycled or NOS components. The other electrolytic caps inside include Nichicon PA, Rubycon PK, JCCON low ESR caps; these all appear to be 105° rated. There are two voltage regulators for 12V and 18V (STMicro 7812 and 7818) and three “shunt” linear regulators (Advanced Monolithic AMS1117). The one opamp I saw was an Analog Devices AD823 JFET input opamp. The digital receiver is a Cirrus Logic CS8416. All in all, some thought seems to have been given to the design and components used (i.e., not the cheapest possible parts).
Soldering quality looks very good, the board was clean of residual flux, and there is no glue on the caps
. The unit gets ever so slightly warm to the touch after playing for a few hours. The power brick stays cool to the touch. Soundwise, I find this DAC very pleasing. Bass extension is very good (I was surprised by this as I thought I read that strong bass was not a forte for these DACs) and not muddy; shimmer on cymbals was delicately rendered. Violins sound clear and sweet where they should be sweet (e.g., The Lark Ascending by Vaughn Williams) and piercing where they should be so (e.g., the opening of Winter by Vivaldi), and without grit or harshness. Clarinets and trumpets similarly. Cellos and saxes had the deeper sonorous tones I expect to hear from them. Everything I played sounded engaging and non-fatiguing, always a good sign. Overall, for me, for relatively low-complexity music such as piano and violin sonatas, female vocals, etc., it provided as reasonable an approach to an in-the-room feel as I can expect from the system I tried it on (Nak SR-3A receiver and DCM TW1 speakers). I need to spend more time with it to evaluate how it renders more complex symphonic music over long passages, but it sounds promising so far. So does the headphone amp. Like the RCA outputs it is dead quiet (disclosure: my hearing tops out at 10kHz), and there is a fairly gentle response to the volume pot, allowing fine adjustment.
I am agnostic about the R2R vs DS debate (and have no desire to engage in that here); presently I have good examples of both (Adcom GDA-700 and Cambridge Audio DacMagic) and find them both very satisfying. It is early days yet for me with the 8x L1387Solo DAC (I’ve played it just for a couple of days), but at present I am finding myself happy to listen to any of these 3 DACs, and find them much more similar than different. Virtually all my non-radio listening is Red Book CDs. If my needs change in the future, the DacMagic and this L1387 (on its coax input) can accept higher resolution feeds, although I have no idea if they will be competitive in that arena with DACs based on more modern chips.
Quirks:
— The case is mislabeled for 15VDC power instead of 24VDC. Seems to be an oversight, or perhaps they have just recently been making the Solo amp version and have not yet produced an updated end plate; the case and its labeling are in fact identical to the L1387 DAC version with the JLH 1969-based amp circuit; you would not know which one it was without opening it up..
— For CD playing via coax input, I hear a slight pop (via the RCA outs to an amp) when the DAC unlocks/locks on the signal (e.g., when opening/closing the CD drawer). I haven’t yet fully explored if this is present for other players (I am using a Pioneer DVP-V7400 as a transport at present) or on other inputs, but I do not recall getting a pop when I hooked up a CCA to the optical input and initiated a radio station stream (listening with earphones in this case).
— The 4 LEDs (three for source indication, one for signal lock) are quite bright, a bit much for a dark room. At least they are red.
