LobalWarming
500+ Head-Fier
Not that I ever found. Hence the DIY traffo-house. It is amongst the easiest DIY (and cheapest) projects in audio. Hence, even I could complete it.
Eufonika (Valve amps from Poland)
andrewchoppa
500+ Head-Fier
I read this but being a technical idiot, I didn’t understand what you were talking about and too scared to ask. So what is a traffo dooverwhacky??Not that I ever found. Hence the DIY traffo-house. It is amongst the easiest DIY (and cheapest) projects in audio. Hence, even I could complete it.
LobalWarming
500+ Head-Fier
Oh the dooverwhacky is a special upside down version of the traffo-house.
The point of the exercise is to connect a 70V transformer between the OTL (H5) which presents a high impedance that OTLs can work into (250-1k ohm). Through the mysteries of a hunk of iron wrapped in non-connected wires an electromagnetic field is created and low source impedance pops out the other side (4 or 8ohm) that is suitable for driving low impedance phones. The traffo-house is the container for the transformers and the input and output jacks.
Your MiniUltimate works on the same principle but within tougher constraints. The output tubes like 6V6 have a high output impedance and need a higher ratio transformer to transform their output high voltage into usable current for low impedance phones. This requires more complex, heavier and expensive transformers to accomplish. Hence why good OTC/SET amps are usually more expensive than OTL amps. Really good high-ratio transformers are difficult and expensive to make.
With an OTL amp, a high ratio transformer isn't required. 40-to-1 or 80-to-1 is good enough. Compared to the 800-1000+ to 1 ratio required to match the usual SET output tubes. This is over-simplified... but so am I.
edited for more correct traffo winding math
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andrewchoppa
500+ Head-Fier
Well thanks for that bud!!!! I do understand. So making an otl play like an otc so low ohm cans join the party. Thanks for the explanation-much appreciated!!!!Oh the dooverwhacky is a special upside down version of the traffo-house.
The point of the exercise is to connect a 70V transformer between the OTL (H5) which presents a high impedance that OTLs can work into (250-1k ohm). Through the mysteries of a hunk of iron wrapped in non-connected wires an electromagnetic field is created and low source impedance pops out the other side (4 or 8ohm) that is suitable for driving low impedance phones. The traffo-house is the container for the transformers and the input and output jacks.
Your MiniUltimate works on the same principle but within tougher constraints. The output tubes like 6V6 have a high output impedance and need a higher ratio transformer to transform their output high voltage into usable current for low impedance phones. This requires more complex, heavier and expensive transformers to accomplish. Hence why good OTC/SET amps are usually more expensive than OTL amps. Really good high-ratio transformers are difficult and expensive to make.
With an OTL amp, a high ratio transformer isn't required. 4-to-1 or 8-to-1 is good enough. Compared to the 100+ to 1 ratio required to match the usual SET output tubes. This is over-simplified... but so am I.
Mr. Lobal tries to make an OTL become a non-OTL. LOL
andrewchoppa
500+ Head-Fier
Mr lobal is a very clever person!!!!
LobalWarming
500+ Head-Fier
Kind of you to say... however, just clever enough to attempt things that should only be tried at home - and never tried again. But not quite clever enough to not blab about them on the internet.
andrewchoppa
500+ Head-Fier
Haha!!!!!! Don't be so bloody modest man!!!! I didn't even know what a truffleduck was!!!!!!!!Kind of you to say... however, just clever enough to attempt things that should only be tried at home - and never tried again. But not quite clever enough to not blab about them on the internet.
andrewchoppa
500+ Head-Fier
Ok - here goes my completely useless and irrelevant review/comparison from a deaf, old, ugly, fat (but heaps of fun guy)And you still haven't made us a comparison.
I'll compare to the 3x gt for reference too.
FWIW, I asked Wieslaw to make an OTC amp for me as I had all low ohm planars when I commissioned him. He built me one as a prototype, asked me to demo then send back and he would build the final iteration. First one sounded fantastic but had a hum which we couldn't get rid of. He actually let me keep the first amp and he sent out the new one 6 months later, without heat sinks on the side, and it was bloody wonderful. 0 hum, sounds awesome!!!!!! His communication throughout has been second to none - I formed a great relationship with him too!!!
Using my JM Audio xtc 2.5 closed backs, Marco custom copper litz/silver hybrid cable terminated in 6.3mm single ended.
Power tubes in Eufonika are Australian Super Radiotron AWV 6NS7 NOS from the 1950s - matched
Power tubes in McChannson are NOS RCA (not sure of timeline) 6G6G
Listening to Aussie band (hardly ever known) BB Steal - Phil Collen from Def Leppard produced this album in 1991 and it is Hysteria volume 2 (that I promise!!!!!!!)
Eufonika is a lovely warmer, mellow sound without being rolled off in any way. Really good balance across all frequencies. Bass is there, mids are actually probably a tad extra which is great for vocals and treble is there without being too bright. My JMs are bright as that's how I requested them (John tunes to your preference) so the Euf tames that a fraction I guess. The bass is wonderful (JMs have a ton of bass too and are the bassiset of my 3 HPs). The timbre is lovely - everything sounds completely natural and in its place. I tetsed them against my Sparkos Aries and the soundstage on the Euf was wider than the Aries. This is not the case on my 3X GT - about the same. I've tried a few tubes on Euf (including Passion For Sound's Apos Ray 6SN7s) and these aussies are the best (the Rays were a fraction more dynamic) out of my collection. I have some little 12au7s with adapter and they have a ton more power but not quite as nice as the Aussie NOS. Honestly, I am VERY happy with my Euf.
McChannson is wonderful too and maybe just the tiniest bit more dynamic (but this could well be the tubes). Once again, great across all frequencies, with a tiny bit more bass/sub-bass (but only a tiny bit) and a smidge brighter. This gives the impression of better clarity but not sure if it's the case .Once again, everything sounds natural. Both amps perfect for rock/metal imo. ANd I love the aesthetic contrast of both - 1 wood and 1 rose gold (my choice) metal.
I swapped to my VOs for final bit and with the ZMF house sound, a tad less treble on both amps and a tad more mids - completely different to the JMs but easily as good. Bass still there but JMs win on bass. HEK Stealths have the least bass of the 3 btw.
Finished with some electro swing from Jamie Berry (Lost in the Rhythm and Peeping Tom) and the Euf was singing!!! Plenty of bass, treble, clarity and slam. McChannson same but with a tad more treble again and maybe a tad more authority/dynamics. But the Euf was $900 aud, and the McC was $1350 aud.
Quick check of the 3X GT and yes - dynamics, slam, control, bass, separation is all better but this is a $5,000 aud SS amp!!
But I'm a massive tube amp fan so I think both Euf and McC are the more "fun" amps and not terribly far behind the Burson. Each has a place in my setup and each gets an equal turn (so none feel left out haha!).
I have a pretty severe case of Upgraditis but honestly cannot see myself ever parting with my Euf or my McC - well done Wieslaw AND Eric!!!!!!!!!!
Added on - Grandiose from Jamie Berry - check this song out. Bass is HUGE, dynamics massive, clarity is freaking there in spades on Euf and McC!!!!!
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I am after a new amp for my office. I love my H5. Was just wondering what people would recommend for a 2nd set up? I have pared down my collection now to only a few high impedance headphones so can be OTL or not. What other Eufonika options are there?
Definitely not useless. Many thanks. Looking to what I read I think McChanson's is closer to my preference.Ok - here goes my completely useless and irrelevant review/comparison from a deaf, old, ugly, fat (but heaps of fun guy)
andrewchoppa
500+ Head-Fier
Haha - thanks!!! And yes - both wonderful amps. McChannson has more tubes to roll too if that's your thing.
roderickvd
100+ Head-Fier
Can you provide a bit more context on what you're looking for? Something different, or something alike? How big would you like it to be? Integrated DAC? Tubes or no tubes? Budget?
Either another OTL or an OTC. Most of my HPs are high impedance but might get a planar again soon
roderickvd
100+ Head-Fier
Since you're in the Eufonika thread here, why not try the H32 hybrid?
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