I needed an alternate way to feed digital coax into my RA Opus 21 so just connected a K11. It's the only DAC/HP amp (along with the K3) I could find that offers digital coax out. Was ready to spend more; glad I didn't have to. Switching from HP amp to digital coax out (with USB source selected...

I just received a request for some pics of a D25 dual DAC mod I performed 10+ years ago; thought I'd pop in here and say hello. Found and sent pics of the mod, D25 schematic, PCB layout, etc. I actually still have the D25 and it still works fine. I did however suffer a light tremor thinking back...

A-cats - thanks for posting about the USB battery pack mod; very cool and I plan to do this one. Even as is, the pack was a great buy; was able to charge my cell phone overnight while off the grid; was at 100% next morning. Certainly smaller than the wallwart I'm transporting, and USB charge...

Quote:     Got to ditto these remarks; still listen to the 003 Mk2 at work every day, for a good portion of the day. Getting such an enjoyable music fix during the day that I'm not at all upset if I miss listening to the 007s when I'm home for the evening. Primarily listening to...

Quote: Switching from a battery bypass connection to an active on-board battery charger would be too slick. Be even slicker if said charger also allowed use of the amp while charging. Quote: I bought one as well and had it connected for less than 20 seconds due to the noise.  I...

Internal pics: op-amp area, aux power area, available space around the input caps (with output board in place); battery tray connection area.                    

Quote:   Would you then suspect your 001 opamp roundup applies to the 002? I guess the real question is whether having two power transistors makes any diff in best opamp that can be used without changes in power handling (versus available capacity). Hope that made sense.....

Hey A-Cats,   Thanks for starting a new thread (just seeing...); looks to be a fun mod project with some easier stuff and some hairier SMD soldering for the steady handed.   I'll help kick things off by documenting the op-amp being used (pulled the case this morning); it's the AD822A. I...

Quote: 1700 mAH (noted above in aH). Way above what this little jewel draws. They had a slightly cheaper model with lower max current out, but went with this one as I can always use it later for other current-hungry applications. I'm usually shy about using universals but this one measured...

@shipsup - Thank you; excellent news. Was a misconception on my part after reading earlier in the thread about popping off some part, plus the fact that I had not read where anyone had actually swapped a cable. Good chance I just missed the post.   @AudioCats - Good to see your post. Over...

^^ Cheers, Rudi.     Switching back to topic of cable swapping, has anyone actually disassembled a SR-003 housing, or have specific instructions on how this should be done? Appears to be press-fit together; trick being where exactly to pry first, and how/with what type of tool. Are the...

Quote:     Your external pack looks promising; thanks for posting. If you can share more specific information about the cell used, the pcb (schematic and parts list), and the connections, others looking for a similar solution might choose to build one.    Was that PCB repurposed...

^^ Dat. Pigtail with portable jack on one end and Stax male on the other.    From modifying a SRD-7 Pro to a 727II, I was glad to have the 003 volunteer to have the first listen (and such a great little product to boot).

Quote:     Thanks for posting pics of plug and jack; I am definitely planning on building a portable to 5-pin adapter.   Was actually hoping for more of a straight pin configuration as to perhaps repurpose portions of a molex connector; no such luck. Do please update if you find a...

For work and otherwise, I use the headband with the SR-003 and with proper bending, it provides just enough pressure to keep the tips pressed against my ear canal opening. That is, I want a tip that seats against the outside of my ear canal rather than plug in like an IEM (have plenty of those...

K, Duncan; thanks for the additional information via PM and email. Reads like your mod is best represented by the following very simple MS Paint edit of the solder side of a 727II amp board. Your stated resistor specs: 500k, .1%, .25 watt, 250v, 5 - 10 PPM. And of course, adjust balance and DC...

Quote:   Very little if any, unless they are really cranked up; even then, much less than other open headphones.   It's one of the reasons I use the 003 at the office; can hear phone, co-workers walking in, etc. but can listen at higher volumes when desired.

Yes, Duncan, it would appear I totally missed the mark. I'm sure we'll get it straightened out once we start collaborating off line. BTW - I am looking at the schematic as I try to follow your logic and changes; feel free to write the reference designators and pin numbers to which you are...

9 - It reads like he is replacing the two 150k resistors that are in series with a combination of resistors with different values.    Visualize two resistors in series; oriented vertically. With the current mod, you replace just the lower 150k surface mount res with an axial lead of equal...

duncan1,   Thanks for posting your modifications and thoughts on the 727ii. Those of us with the 727ii, and others looking for a mid-cost electrostatic solution, really appreciate the time and effort you put into typing out your findings, however they may be formatted.   I made my way...

Trends TA-10 series T-amps (speaker amps) are inexpensive and do a decent job. I used a maxed out 10.1 and SRD7-Pro with a pair of HE60s for a while; decent+ sound.   Plus side: You'll then have a nice little speaker amp after you get a dedicated stat amp. Minus: At the same combined price...

Quote: I've been listening to an unmodded 727II and SR-407s since this past Saturday; running balanced out of the warmish Opus 21 (5v goodness); volume pot on amp disabled. Compared to the uber BHSE class, it does have its limitations; however, I've been extremely impressed with the...

Just got a SRM-727II from Justin; shipped in record time. Great sponsor; great guy. Paring the 727 with the bang-for-buck SR-407. Resistors for the mod are on order; even ordered a new soldering tool for the occassion (my old Weller workhorse is from the 80s...). Plan to run-in stock and then...

Quote: Dastardly nature exemplified! Would you believe I was just looking at the 323 specs on Stax site. Also read Dr. Gil and Sprit's comments on the 323 from some time ago. Blast this place... What sent me over the edge was when I replaced a long-blown fuse in the 252 and hooked...

I've been listening to a speaker rig at home and CIEMS at the office, so stopped in to sell a pair of HF-2s I was not using enough. Started browsing the Stax area and before I knew it, pulled the trigger on a pair of SR-407s. They're pretty amazing even through a SRM-252 amp.  Some things never...