[StarTreker]

SP200 is primarily designed to AMP On Ears and Over Ears, it's not meant for IEMs, which is why your experience is not ideal. Good to hear at least 1-pair worked ok however.

With these guys messing around with chip and caps replacements on here, I bet they could build a custom SP200 for IEMs.

 

[Cableaddict]

@Cableaddict I have checked the Nichicon LKG1E152MESBCK caps, but they will be available next year So I will replace the caps only on the inputs. That's sad

Wow. Mouser USA had said they will be in stock by Sept 15th, when I ordered, and I have 10 on backorder. Now (as you say) they've changed it to June 2022!
- And they are the USA's main Nichicon retailer, so this is bad.

Elna doesn't have 1500 in their RFS series (Simic 2) but they do have 1000uf / 25v and it looks like it will easily fit. (sideways)
That might be worth a try, though it would be nice to have a scope and test for ripple afterwards. Still, your ears are the best test equipment so maybe worth an experiment. They are certainly excellent caps, sonically.

Or maybe try the (still very good) Nichicon UFG1E222MHM (Muse) which is 2200uf. Lots of high-end studio equipment uses UFG's, so they can't suck.

Maybe someone has another idea? - Or maybe just adding mf and hf bypass caps to the stock 1500's would be enough. I have no idea.

 

[animalelder]

Would using an iEMatch+ by iFi with a 1/4” adapter allow for using IEMs with the SP200? It reduces gain by 12 or 24db via switch. Or is the issue somehow output impedance related? I thought that this amp’s output impedance is near 0 ohms…

https://ifi-audio.com/products/iematch-plus/

 

[Cableaddict]

"Near zero ohms" can mean anything, it's just marketing.
There must be a reason they don't actually give the impedance in their specs.
One very credible source tested and found 1.3 ohms, which would perfectly explain the sound I get with my 9 ohm IEMs.

Another fairly credible source says the output impedance is significantly lower, but I suspect they made a mistake.
--------

As for inline resistor networks: (H-pads, L-pads, etc) Realize that they typically do NOT (theoretically) change impedance, just resistance. (Including that IEM Match device, which does not claim to help with impedance issues.) - Although I would not bet my life on this, and there ARE a few different ways to construct such a network, so some might be better than others. So Far I have only tried an 80 ohm unit from Ebay-China. It brought my IEM's to "approximately" the same volume as my 600 ohm cans, and it did seem to bring back some LF and remove the harsh mids.
However, it also kills a significant amount of HF. - Enough that I can't stand to listen this way.

I'm in the process of trying a modified H-pad design I recently found on some DIY forum. I have the parts, just have to find the time.....

FWIW, that iEMatch unit is a bit overpriced, though I guess it's convenient for some users. Being passive, it can't be anything more than two separate resistor networks, with a switch. Maybe $20 worth of parts, all-in.
Such is the Hi-Fi world ......
Still, if anyone has used this device, I'd live to know if their claim about "no HF loss" is really true. (I doubt it.)
If so, then there is hope, but numerous negative revues on Amazon say it ruins the sound. so ......

I wish there was some simple, ACTIVE device that could act as a non-coloring, unity-gain (or ideally gain drop) "impedance lowerer." High input impedance & maybe 0.1 ohm output. - But nothing seems to exist, nor can I find any plans for one.

 

[JoeSlovakia]

@Cableaddict have you thought about replacing the 4 SMD caps right after the PSU? What are those? 470uF 25V?

 

[Cableaddict]

@Cableaddict have you thought about replacing the 4 SMD caps right after the PSU? What are those? 470uF 25V?

Working on smd stuff scares me. Pretty easy to damage your circuit board, IMO.

Those appear to be Panasonic TC-V series aluminum electrolytics (I think) which are far from audio grade. Yes, 470uf / 25v and polarized.
I neglected to trace the leads when I had mine open, but from the top they seem to be the first filter caps after the tranny, in which case, (AFAIK) the following caps are more important. Except usually (AFAIK) the first caps are the largest. Maybe someone could reverse-engineer a schematic of just the psu section?
It might even be worth bypassing those from underneath. - But bypassing psu caps is supposedly a bit harder than coupling caps. I may try it with 2 values, one for MF and one for HF, but I will be guessing. (It won't blow anything up if I get it wrong.) Or I may not bother.
- What am I saying? Of COURSE I will try it eventually. I won't be able to help myself. lol.... Maybe a 5 uf film cap for mids and a 0.1 PET for highs? Maybe somebody out on this forum can suggest better values?

Anyway, bear in mind that I know just enough about electronic theory to destroy some pretty expensive gear. I'm REALLY not the right person to make any decisions about these things. Swapping a high-end cap with the right specs (in this case, a good ripple current rating) for a cheaper cap of the same value is easy. Adding bypass caps (without owning a scope) is fairly easy as long as you use your ears and are prepared to remove them when needed. - And that's about as far as I can go. I don't even swap op amps, unless the replacement is known to have the right properties for that particular circuit.

The one thing I DO know (after 30 years of modding high end recording studio gear with help from the best techs in the business) is that the psu absolutely does matter in terms of audio quality. It stuns me that many audio techs don't understand that.

 

[JoeSlovakia]

Thats why I want to replace those 4 smd caps right after the PSU and also the two 1500uF caps to have the best result.

-----------------------------------------
Edit: My dad is able to replace those SMD caps. thinking about these Nichicon UKZ1E471MHM but maybe some Philips 25SEK470M or 25SVPK470M os-con caps would be better. what do you think @Cableaddict ?

 

[Kezter]

Hi all,
I was wondering if anyone has ever had problems with their SP200 overheating? I have noticed sometimes with mine, when the volume is on high side I will hear a relay click inside the unit and the sound stops coming out.. then after a few seconds it clicks back on, and off again, etc. The higher the volume, the more often it will click off. Yesterday was very hot and it was clicking off very consistently, whereas today is much cooler and I can't get it to happen at all.. so it feels like it might be a thermal issue?
I have done some googling and haven't seen any other examples of this problem.

 

[Cableaddict]

Thats why I want to replace those 4 smd caps right after the PSU and also the two 1500uF caps to have the best result.

-----------------------------------------
Edit: My dad is able to replace those SMD caps. thinking about these Nichicon UKZ1E471MHM but maybe some Philips 25SEK470M or 25SVPK470M os-con caps would be better. what do you think @Cableaddict ?

Again, I really don't know. If they will fit (along with those other rather large 1500's you will eventually install) then sure, why not? But they may NOT fit, @ 16 x 25mm.
And again, it might be just as good, or even better, to just add MF and HF bypass caps. I have no idea.

 

[JoeSlovakia]

Again, I really don't know. If they will fit (along with those other rather large 1500's you will eventually install) then sure, why not? But they may NOT fit, @ 16 x 25mm.
And again, it might be just as good, or even better, to just add MF and HF bypass caps. I have no idea.

But which would you recommend?

 

[StarTreker]

Hi all,
I was wondering if anyone has ever had problems with their SP200 overheating? I have noticed sometimes with mine, when the volume is on high side I will hear a relay click inside the unit and the sound stops coming out.. then after a few seconds it clicks back on, and off again, etc. The higher the volume, the more often it will click off. Yesterday was very hot and it was clicking off very consistently, whereas today is much cooler and I can't get it to happen at all.. so it feels like it might be a thermal issue?
I have done some googling and haven't seen any other examples of this problem.

We have talked about how sometimes the SP200 will get quite warm, while other times it remains cool. We're not quite sure why that happens, and have been waiting for an electronics engineer, to do some audio science to figure it out.

What I haven't heard of however, is the relay clicking on and off as if it's entering a thermal protect mode, that hasn't happened to me yet.

Other then volume, what kind of load are you putting on it? How many ohms is the cans? I'm trying to figure out if your overloading the amp or it just simply is defective.

I will say that I only sometimes put my volume past 50 to 60%, but not for headphones. When hooked up to a self amplified Bluetooth speaker in wired mode, while watching a stream in a noisy room ya.

But it's not good to run an amp beyond 50% on a permanent basis, not the best on the internals. We got these guys in here wanting to replace chips and caps, you'd think they'd be perfectly qualified to figure it out.

 

[Kezter]

Thanks for the response. I am mostly using HiFiMan Sundaras which are 37ohm, however once the problem starts it can happen very consistently and at lower volumes with cans like SHP9500.

It's weird cause today I have been deliberately trying to push them, my Fostex T50RP mk3 are probably the headphones I can run the highest on this amp and still be comfortable (which is only around 50% in high gain). I have been listening to them pretty loud all day and it's been fine, the amp is warm but today has been much much colder than yesterday when it was happening a lot.

One other thing is I am using XLR Y splitters from my DAC to two headphone amps (the other is an Arcam rHead). It is my understanding that this should be fine? It's hard to test as the problem is very intermittent.

 

[JoeSlovakia]

So I made a list of caps, that I will buy and test out:

4x Panasonic EEH-AZS1E471B - Aluminium Organic Polymer Capacitors 25VDC 470uF 20% LG HiRip/LoESR for the power supply part
2x Nichicon LKG1E222MESYCK - Aluminium Electrolytic Capacitors - Snap In 2200uF 25 Volts 20% as a replacement for the 1500uF caps and as an upgrade
2x Panasonic EEU-FS1E222 - Aluminium Electrolytic Capacitors - Radial Leaded 25VDC 2200uF 10000H - same as the mentioned Nichicon but with lower ESR and high Ripple current
For inputs I will order some Nichicon FG caps, I have 6x KZ caps that can be used, but in a Facebook DIY thread they wrote, that I should use FG and not KZ, as FG caps have better sonic performance. Has anybody tested the difference between the KZ vs FG?

EDIT1: I think that I will use the Panasonic caps for the power, as they have lower ESR and high ripple current. Also the 2200uF caps will be an upgrade.
EDIT2: Even those stock 1500uF Panasonic caps after the PSU are high Ripple, low ESR. From what I can see those are FM series caps, so not bad at all for the PSU. Those stock 470uF SMD caps are worse, ripple current 850mA, the impedance is arround 0,08Ohm, the replacement caps have a nice 3500mA ripple current, ESR of 0,014Ohm.

 

[Cableaddict]

Good list, Joe. It should help a lot of folks who wanted to try this.

Thoughts on the psu caps:

1: I don't know that you need to get so hung up on having the highest ripple current rating. AFAIK, you only need high enough to deal with the particular circuit being worked on. This psu is pretty tiny, compared to something in a high-powered tube amp.
------------

2: UFG better sounding than UKZ? I doubt it. In my research, I found that ONE thread where ONE guy claims this. No one else does, and Nichicon themselves say the UKZ was always their premium AUDIO cap. Many guys used them instead of Black Gates. The downside is they don't come in very large values.
Having said that, I own two super-premium pieces of recording studio gear that use FG, but that's probably due to size restrictions inside the 1U chassis.

As of this year, their new premium audio line is the LKG. They also have pretty high ripple current ratings.
Oddly, they only seem to come as snap-in in values under 8200 uf.
------------

3: Going to 2200 is not necessarily an upgrade, unless 1500 is starving for power on peaks, and it sure doesn't sound like it to me with either 600 ohm cans or 9 ohm IEMs. Going bigger might actually end up sounding slower, unless you do a MF and HF bypass. Wait, you ARE doing bypass with those organic polymers, so very good then. I think it's worth a try IF THERE'S ROOM. (I could JUST barely make the 1500's fit, so good luck! )

Of course, probably, there won't even be a sonic difference between the two, and either will be an improvement over stock.
Too bad you don' have a second SP200 to keep stock, so you can compare. I'm not sure how you can audition various caps, otherwise.
----------------------------------------

I'm a huge fan of Panasonic FM caps, BTW. excellent sound for the money, and they seem to last forever.

 

[JoeSlovakia]

Yes, we don't need to have the highest ripple current capability. I talked to my dad who said, that I can have higher ripple, but I should search for the lowest ESR possible. Those 470uF are oscon caps if I am not wrong and those should be pretty good.

The 2200uF caps from Panasonic are smaller then yours and there is no 1500uF version of it available. 1,85A ripple for those LKG is far enough for this application, but what is the ESR?

And I want to find one stock unit somewhere in Slovakia/Czech Republic to borrow. We will see.

The Facebook group did not recommended to replace those caps, as there is no point. It will not have better sound etc. Everybody there was afraid to solder those SMD caps, because it can damage the board bla bla bla.. my father, who does this kind of job on a daily basis is not afraid so neither am I