Battle of the Champs
- Thread starter S-Man
- Start date
How do you define the differences of modulus implementation in contrast with the normal 3886 ?
@S-Man, I can't figure out what's the first one, can you elaborate ?
toprepairman
pfm Member
Wasn't it Fender who did champs? Usually just the one 6V6, though you'd need 2 for stereo. Ok then, back to the pub....
S-Man
StrivingON
Well it's obviously not that interesting 
The top one is an Akitika which is an LM3886 amp with a regulated single rail supply and with capacitor coupled output (like a Quad 303). The grounding scheme is a bit unusual and the board layout is not conducive to gettting a neat result.
I had previously built it with a different physical layout but decided to fit it in a smaller chassis. Of course it's impossible to be sure, but I think it sounds significantly better now. Initial listening impressions are that it is very good indeed!
Further listening required, but it's interesting to compare an LM301/LM3886 composite amp that's had many 100s or hours of development by a DIYAudio committee and built with the finest audiophile bits to an unusual implemtation of an LM3886 built with budget bits. I think one stark B naked resistor on the composite amp cost more than all the resistors on the Akitika put together!
The top one is an Akitika which is an LM3886 amp with a regulated single rail supply and with capacitor coupled output (like a Quad 303). The grounding scheme is a bit unusual and the board layout is not conducive to gettting a neat result.
I had previously built it with a different physical layout but decided to fit it in a smaller chassis. Of course it's impossible to be sure, but I think it sounds significantly better now. Initial listening impressions are that it is very good indeed!
Further listening required, but it's interesting to compare an LM301/LM3886 composite amp that's had many 100s or hours of development by a DIYAudio committee and built with the finest audiophile bits to an unusual implemtation of an LM3886 built with budget bits. I think one stark B naked resistor on the composite amp cost more than all the resistors on the Akitika put together!
Interesting to me! Just couldn't figure out what the first amp was. I look forward to your comparison with the MyRef, but I'd be surprised if you found it as good.
By the way, I highly recommend swapping the LM318 in the MyRef for a ADA4627, then bypassing C9 the feedback cap - it's a big jump forward.
By the way, I highly recommend swapping the LM318 in the MyRef for a ADA4627, then bypassing C9 the feedback cap - it's a big jump forward.
S-Man
StrivingON
I was not impressed with the MyRef at first. It's taken quite a lot of fiddling with the system to get it to sound really good. The Akitika really is not far behind in sound quality, if at all.
My feedback cap is a Black gate PK. What are you using ? Bypassed by?
What didn't you like about the MyRef at first? What did you do to improve it?
Re. bypassing, I mean take it out of circuit completely with a wire link. It's no longer needed if you use an opamp that has good DC offset performance, and you get a nice performance boost. The big change though is replacing the LM318 with the ADA4627.
S-Man
StrivingON
Must admit I'm nervous about admitting what I did in case the fun police come and tell me all the technical reasons why I'm deluded, but here goes; I changed interconnect and mains cables.
The issue I orginally had was a rather forward upper midrange, which was fine with good recordings but unkind to lesser recordings.
Ah, see what you mean about bypassing. That makes a lot of sense. If you mention that on DIYAudio you will have the self appointed community special constable trying to save you from eternal damnation for daring to run a dc coupled amp
sq225917
Bit of this, bit of that
Ramon, well it's using both channels of an lm4780 wrapped up in an error correction loop with an lme49710 and a dc servo.
https://www.neurochrome.com/parallel-86/
It's a very good amp, quieter than anything else I've owned and seems to have no real signature of its own. If I could point to any failing it's not quite as tight as an ncore in the sub 100hz region. But it's also considerably sweeter in the treble and mids. So I'm doing a bridged pair to see if they deliver that last ounce of bass grip thst would make it a truly stunning amp.
It's the best amp I've had by quite a margin.
https://www.neurochrome.com/parallel-86/
It's a very good amp, quieter than anything else I've owned and seems to have no real signature of its own. If I could point to any failing it's not quite as tight as an ncore in the sub 100hz region. But it's also considerably sweeter in the treble and mids. So I'm doing a bridged pair to see if they deliver that last ounce of bass grip thst would make it a truly stunning amp.
It's the best amp I've had by quite a margin.
Must admit I'm nervous about admitting what I did in case the fun police come and tell me all the technical reasons why I'm deluded, but here goes; I changed interconnect and mains cables.
The issue I originally had was a rather forward upper midrange, which was fine with good recordings but unkind to lesser recordings.
Ah, see what you mean about bypassing. That makes a lot of sense. If you mention that on DIYAudio you will have the self appointed community special constable trying to save you from eternal damnation for daring to run a dc coupled amp
Ha, yeah he did, but got the error of his ways explained to him by someone else. I just ignored him. It's prefectly safe as long as there is no DC at the input, plus the board has got a DC protection relay.
So you are using Z foils? I recently fitted one for the 12k feedback resistor, a really useful improvement.
S-Man
StrivingON
I went for the "audiophile cost no object" build straight off, as below, but with C9 as BG PK and no (shorted) input cap C13.
1. C9 (Cerafine)
2. R12 (Z-Foil)
3. C30, C32, C12 (Amtrans AMCH)
4. C13 (Mundorf Supreme)
5. R7 and R10 (Z-Foil)
6. C101, C201 (Mundorf MLythic AG)
7. R37 (Z-Foil)
My Z-foils are the Chrarcroft ones from hifi collective. The ones with a pitch that's slighlty too big for the pcb :-(
1. C9 (Cerafine)
2. R12 (Z-Foil)
3. C30, C32, C12 (Amtrans AMCH)
4. C13 (Mundorf Supreme)
5. R7 and R10 (Z-Foil)
6. C101, C201 (Mundorf MLythic AG)
7. R37 (Z-Foil)
My Z-foils are the Chrarcroft ones from hifi collective. The ones with a pitch that's slighlty too big for the pcb :-(
Ncores are very well speced but numbers don't tell the whole story. There is a huge gap between them and Naim-likes, they sound completely different to me, old vs new. They have the bass but you have to be on neutral side of sound to really like them. The LMs in the other hand were always very musical although relative new technology and with very good drive (could almost drive maggies) but I never thought they had the specs.
I very curious about Mod86 against normal LM or a well specs AB amplifier
I very curious about Mod86 against normal LM or a well specs AB amplifier
S-Man
StrivingON
Naim and Naim-likes are quite coloured. Not an ideal reference (even if some like the sound effect).
sq can tell you about Mod86P versus AB amp(s).
I have been listening to the Akitika for the last 3 days. No compulsion to change to the MyRef or my KT88 amp or any others at the mo. Still early days though and sometimes I take weeks to make my mind up.
FW specs AW:
Akitika - 0.004% THD
MyRef about 10X lower
MOd86 about 5X lower again (but it's hard to find a like for like comparison)
sq can tell you about Mod86P versus AB amp(s).
I have been listening to the Akitika for the last 3 days. No compulsion to change to the MyRef or my KT88 amp or any others at the mo. Still early days though and sometimes I take weeks to make my mind up.
FW specs AW:
Akitika - 0.004% THD
MyRef about 10X lower
MOd86 about 5X lower again (but it's hard to find a like for like comparison)
sq225917
Bit of this, bit of that
Ramon, I have no measurements for the mod86p other than those Tom provides, which I have no reason to doubt. I did have the chance to try a pair of ncore, back to back with my mod 86p with the same gain and using the same balanced pre, source and wires throughout. Also tried back to back with my Muse 200 class ab as well. The ncore are somewhat ruthless, a touchy grainy in the treble perhaps and have vicelike control of the bass. Though maybe a touch one note under 100hz. The mod86p are a little sweeter, seem a touch more resolved in the bass in terms of timbre and decay but font have the effortless stop start ability of the ncores with plosives. The Muse is way behind in all measures and enjoyment.
With the pre at usual volume level on the dial, Im not a loud listener, thete is no noise from any driver on my speakers. Even with my paradise selected as the input with the needle lifted, there's not even hiss. I have to wick it up a good 20db on the pre before transistor roar is audible even with ears on the tweeters. It really is remarkably quiet and my pre and powers aren't even boxed up, they're just draped over my rack.
No fancy parts, no boutique bits.
I shall complete the bridged pair and case them up in next couple of weeks
With the pre at usual volume level on the dial, Im not a loud listener, thete is no noise from any driver on my speakers. Even with my paradise selected as the input with the needle lifted, there's not even hiss. I have to wick it up a good 20db on the pre before transistor roar is audible even with ears on the tweeters. It really is remarkably quiet and my pre and powers aren't even boxed up, they're just draped over my rack.
No fancy parts, no boutique bits.
I shall complete the bridged pair and case them up in next couple of weeks
themystical
pfm Member
I could fancy building something like this. I know my skills are up to it, I designed and built similar stuff when I was a 6th former, got quite into it and still have odd bits of test gear and the like that I made. SQ, I'd be very interested to hear what you've built and how you get on with it.
misterdog
Not the canine kind
I'm building the same bridged pair as Si, so we can compare into ESL's and Yammies.
Though mine are Monoblocks.
I also have N-Cores and find that the N-Cores are neutral while the chip-amps are natural.
Interesting that Tom talks about the distortion 'profile' even with such low distortion.
Though mine are Monoblocks.
I also have N-Cores and find that the N-Cores are neutral while the chip-amps are natural.
Interesting that Tom talks about the distortion 'profile' even with such low distortion.