[ph0n6]

I got a pair of 8820 myself, sounds very good for the price, I prefer it to the OPA2107.
Anyway, have anyone got their hands on the Muses03? It seems that mouser have them in stock but only in 2000 units reel?

 

[FritzS]

Take a view to MUSES8920 too
http://www.njr.com/MUSES/series/MUSES8920.html
http://www.njr.com/semicon/PDF/MUSES8920_E.pdf

 

[Rroff]

I got a pair of 8820 myself, sounds very good for the price, I prefer it to the OPA2107.

Anyway, have anyone got their hands on the Muses03? It seems that mouser have them in stock but only in 2000 units reel?

 


Showing no stock and 13 week lead time for me (UK version of mouser) - as its a new line possible the minimum order quantity will change when/if they actually have them properly in stock instead of ordered in on demand.

Personally don't really rate them mostly because of the price versus other offerings that are either really close or I can't tell the difference and much cheaper.

 

[Lohb]

  Take a view to MUSES8920 too
http://www.njr.com/MUSES/series/MUSES8920.html
http://www.njr.com/semicon/PDF/MUSES8920_E.pdf

have you compared it vs the newer Muse01/02 ?
Interesting, and a great price.

 

[snellemin]

Bought me something interesting.  Sounds pretty good.  A bit smaller than the Burson V4.  It's uses dual opamps, and one being the buffer to the other.
 

 

[raoultrifan]

Looks originals, pretty hard to find.

 

[Tuluum]

First off, I wanted to thank everyone for their feedback.. It is much appreciated!
 
Quote:

If you like tubes then stuff like the OPA2228 (note its only really stable above gains of 5, not unity stable and fussy about compensation caps, etc.) and OPA1602 are worth a consideration. The 2228 has a rich tube-a-like mid-range but the bass and treble are much more solid state sounding while the 1602 is mellow and neutral slightly rolled off towards the top and bottom.

Personally I wouldn't say the OPA1611 or 1612 and OPA1688 are really for someone who like tubes as in my experience they have a slightly bright and energetic sound.

Topology wise I'd either look at O2 variants or something like the PPA - both are possible to simplify significantly with great sound if you want i.e. miss out the power management circuit on the O2 if its entirely desktop wired in if you want to keep it simpler.

While the O2 type setup is pretty hard to beat without going super high end my current favourite is actually a 4 channel (active ground) setup that is similar to the PPA but omits the outer loop and buffer using AD8066 op amps (as its setup for "balanced" output it uses separate isolated power supplies for each left and right channel).

 
Thank you specifically for this.  I had been eyeing the PPA for a bit, but I'm hesitant to do such an involved build without actually hearing one first.  Ive gotten over that, since I think its just how its going to have to happen right now
 
I'm still debating between the o2 and the PPA, but I think Ill end up going for the PPA.  I need to get some parts, but have a lot on hand and I like that it has a discrete stage and can be class A biased.  I even found a thread about turning it fully discrete, but that will be down the road (if I ever get there).  I'm going with the suggested AD8610, but will also be purchasing pairs of NE5532 (ON semi), OPA2228, and OPA1602. They may not make their way into the PPA, but I think they will be fun to play around with in small cmoy/3-channel cmoy/a47 projects.
 
However, having to etch my own PCB isn't too exciting to me at this point in my life, so that's a big tip of the hat to the o2 (PCB is readily available).  When all is said and done, Ill probably go with the PPA, test it out on a breadboard and never move it into an actual enclosure anyway though..  I like to tell myself I don't do things like that, but I do.
 
Do you have any more info/links on that 4-Channel PPA variant? ETA: Now I'm also looking into the CK2III...

 

[Rroff]

Closest (and its missing quite a bit of what makes the PPA the PPA) is this http://www.head-fi.org/t/553236/pseudo-balanced-amplifier-pba - I came up with my own reworking of the PPA for balanced use which I don't really have committed anywhere as a cohesive thing at this point - I'm still experimenting with what works best.

IMO the O2 type topology is very hard to beat with a relatively simple circuit you have to go very high end even to match it - that said IMO nwavguy kind of sabotaged it in an effort to prove a point - despite it being somewhat subjective some simple modifications at a little more expense largely using "boutique", etc. components does make it far more pleasurable to listen to and tolerant to a wider range of operating circumstances - the original design/component selection performs very well within controlled circumstances but in the wider world you can easily encounter some issues.

 

[adydula]

Someone has looked at the O2 on an AP analyzer....you might find this interesting..

https://www.neurochrome.com/o2-headphone-amp/

Alex

 

[Rroff]

Oh nice not seen that one before.

I've always been sceptical about the NJM4556 on the output - seems to work fine with high current demanding headphones but with my HD600s at times can notice loss of articulation and higher pitched vocals can sound almost "genderless" which I've kind of ascribed to the slew rates though that article tends to imply that the slew rates are just about ok.

You also have to be pretty careful with the power level of the source input versus the amps supply vrms, gain and volume control position as otherwise as per the article its really easy to drive the amp into distortion - within controlled circumstances or with some slight tweaking it works much better.

I made a low voltage version with OPA1612 gain, LMH6643 output op amps, changed C10 (0.22uf film cap) for a 10uf audio grade aluminium electrolytic (in this case elna silmic ii) and uprated the other film caps to polypropylene where appropriate and changed the regulators to a LM317/337TG pair and its far more pleasurable to listen to with noticeably more spacious sound - LMH6643 do kind of degrade the noise performance a bit but keep the current capability intact should I want it.

 

[NCSUZoSo]

 
 

Finally took the plunge and upgraded the first four surface mount opamps on the Creative ZXR (1st stage). I made a mess out of it right out the gate. I had pads lifting off the PCB with the op-amp itself, not realizing I needed 550-600F for the lead free solder used on the board. This lead to me having to repair about 8 pads in total (finding their nearest trace connection point and bridging to the op-amp leg/pad area). In the end, I think it came out decent. When a few people first saw the pic with the opamps removed were like d*mn, he killed his modded ZXR, lol.
 
The stock opamps were  JRC 2114s and I upgraded them to BB 2604AUs. Haven't had enough time with the card using surround sound to give an opinion on a change.


 
Some of my modding rig/engineering tools.


 
 
If I notice enough improvement in the sound I did make a video of the removal and the install, but I think the best option for anyone wanting to upgrade the rear speakers and center/sub opamps is to invest in DIP8 to SOIC8 adapters

$5 + $6 S/H is 1/2 the cost of similar adapters elsewhere and if you buy 4-6 of them, the shipping isn't so bad.


 
 
http://www.ebay.com/itm/361490134147

Just thought I would throw this in here in case someone ever tries to do this and here is the full ZXR thread post: http://www.head-fi.org/t/623079/creative-sound-blaster-new-series-z-zx-zxr/3360#post_13237344

 

[Spider fan]

 
Hi gr8soundz,
 
The STX, ST, and STXII all use the same opamp setup. They use 3-duals so with Sparkos you would need 3-SS3602's (2 for the I/V sockets and 1 for the buffer/LPF). If you are using the headphone out only the I/V opamps are used, if you are using the line out then all 3 sockets/opamps come into play.
 
This is the ebay store to buy from http://www.ebay.com/itm/Dual-Discrete-Op-Amp-SS3602-/141461456047?hash=item20efc284af:g:EqYAAOSwCZ5Vfdzn
That is Sparkos Labs ebay store, they come direct from Andrew and shipping is only $6.00. He also takes offers for them, so you can hit him with a price and if it's close he will counter offer or accept.
 
Just a suggestion, if you are just using the line out, pick up one and use it in the buffer/LPF socket which is only used for the line outs. That is how I started with the Sparkos
by using I/V: LME49720 x 2
LPF: Sparkos SS3602 descrete
That setup got me to move to eventually to using all Sparko's duals in the STXII and the sound to me is incredible.
 
Hope this helps and if you have any questions let me know...
 
Ren

Thanks your post got me researching the Sparkos SS3602 and after reading the reviews online I had to order one to replace my 8820.  Andrew the owner was super helpful answering my multiple questions too. 

 

[zilch0md]

Let's hear it for Sparkos Labs!  
 
I so love the way the SS3602 sound in the input voltage gain stage of my portable iBasso PB2, with dummy buffers (no current gain, but less noise), that this has become my absolute favorite amp. 
 
I find my SS3602-equipped iBasso PB2 portable amp to be:
 

1. Better than my Meier-Audio Corda Stepdance (the SS3602 has a more analog, less "crystaline" sound, yet every bit as neutral and resolving and with the same black noise floor)
2. Better than my CEntrance DACmini CX amp section (the SS3602 isn't as "grainy" in the treble)
3. Better than my Oppo HA-1 amp section (the SS3602 isn't as bright, nor is at as harsh with HD800, which just can't be used with the HA-1)
4. Better than my Metrum Acoustics Aurix (the SS3602 has much better dynamics, but just as neutral and with just as low a noise floor)
5. Better than my iBasso PB2 with any other op-amps, including the Burson V5 Duals, with which I was very content until I heard the SS3602 (which are more resolving, with a lower noise floor, not to mention much better quality control and a smaller form factor).

 
The SS3602-equipped iBasso PB2 sounds so much better than my other amps, I've been using it, with multiple headphones, all with balanced cables (PM-1, HD800, Beyer DT880 600-Ohm)  to beta test the new Oppo Sonica DAC that was just released. Put a good DAC in front of an SS3602-equipped amp and you can really appreciate what Sparkos Labs has accomplished.
 
I think it's primarily due to the low noise of the SS3602 (see the comparison chart below), combined with its power, which allows me to operate at lower gain settings for any given load, combined with the fact that my PB2 is battery powered - having no need for AC power conditioning. The resulting pitch black noise floor allows lots of micro-details to be heard, even at low listening levels. Gone is the tendency to play too loudly, just to enjoy everything the recording has to offer.  
 
It looks silly, using a portable amp with a big desktop DAC, yet my ears say it's anything but silly.  
 
 

 
 
SS3601 (single) comparison chart:

Mike

 

[dukefx]

I also love the SS3602. It has clean bass and an overall very natural sound.

 

[northendjazz]

I've been running the single sparko's SS3601 in a Neco Soundlab V4 Dual Loving every minute but sparko's state "+/- 6V to +/- 18V supply voltage range" while the V4 is a 20V. I'm not going to roll any more opamp's in the V4 so do I ask the amps maker to reduce the supply voltage to 18V to be within the sparko's range?