Triad VPM24-1040 would be my first choice, or VPT-1040 or whatever R-core or toroidal you can find with 12 V secondaries. Plenty of nice R-core sold on ebay.
I used VPM24-1040 as suggested by Richard for both phonoclone and sapphire line preamp.
However, for a recent amp and crossover project I bought from Transformatory toroidalne - Producent transformatorow Toroidy.pl
These are top quality trafos for very reasonable prices. The audio-grade series
Toroidal transformers AUDIO GRADE - Shop Toroidy.pl
it's just fantastic, and if you want really impress your mates, these may be even better
Toroidal transformers SUPREME AUDIO GRADE V2 - Shop Toroidy.pl
A friend that works in medical equipment PSUs told me that their company made measurements and these transformers are on a pair to the well-respected Plitron
However, for a recent amp and crossover project I bought from Transformatory toroidalne - Producent transformatorow Toroidy.pl
These are top quality trafos for very reasonable prices. The audio-grade series
Toroidal transformers AUDIO GRADE - Shop Toroidy.pl
it's just fantastic, and if you want really impress your mates, these may be even better
Toroidal transformers SUPREME AUDIO GRADE V2 - Shop Toroidy.pl
A friend that works in medical equipment PSUs told me that their company made measurements and these transformers are on a pair to the well-respected Plitron
Assuming they are not complete charlatans those look to be fine. I'd stay away from the metal potted ones because of the leads coming out the bottom - the transformers will be inconvenient to mount unless you put them on the outside of the case.
They are not charlatans, 😀 the products are ok. I used some models for electron tubes amplifiers.
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Hi Richard, I think you remember me (Pietro), you assembled the low gain version (3,6,9dB) of the Sapphire preamp. I do not have any interest with them. I am experimenting with an high quality gainclone build and replacing a good toroidal bought on RS component with one of their trafo made a serious sonic difference.
Power transformers do influence the sound. Quite significantly I think.
I could not tell you if such-and-such a model would sound better or worse than another one, however, given the same VA rating and type.
I could not tell you if such-and-such a model would sound better or worse than another one, however, given the same VA rating and type.
Ｈi Richard,I bought 24 pieces of BC327-25 and BC337-25 from mouser. As shown in the figure below, the hfe difference is about 100. Can I use it?
Yes, they are all like this. The npn and pnp are nominally close, but always distinctly different from each other.
Indulge me for moment if you will. My longstanding reference cans, Sennheiser HD-600 have finally lost stereo balance due to worn down connections in one ear.
I fairness, I've had them for going over 20 years, and I bought them used back then.
I'm currently listening to my backup, Sennheiser HD 25 (70 ohm). For the price, and a closed back design, these are swift and surprisingly musical. I also have a set of Sony MDR1A (24 ohm) which I don't like so much. Too much bass boom and a rasp to the upper midrange. Just ordered a set Shure SRH840 but propose to buy back a replacement set of Sennheiser open back... but there's so many variants now compared to back when it was either the HD-580 if you were cheap or the HD-600 if cost was no object.
Recommendations?
(I haven't tried massive numbers of headphones over the years, sticking with my HD-600 after having a set of GRado SR-60's before then, and briefly flirting with some AKG701/702 a few years back (good, but somewhat remote soundstage and there's a upper midrange bump I don't care for.)
I fairness, I've had them for going over 20 years, and I bought them used back then.
I'm currently listening to my backup, Sennheiser HD 25 (70 ohm). For the price, and a closed back design, these are swift and surprisingly musical. I also have a set of Sony MDR1A (24 ohm) which I don't like so much. Too much bass boom and a rasp to the upper midrange. Just ordered a set Shure SRH840 but propose to buy back a replacement set of Sennheiser open back... but there's so many variants now compared to back when it was either the HD-580 if you were cheap or the HD-600 if cost was no object.
Recommendations?
(I haven't tried massive numbers of headphones over the years, sticking with my HD-600 after having a set of GRado SR-60's before then, and briefly flirting with some AKG701/702 a few years back (good, but somewhat remote soundstage and there's a upper midrange bump I don't care for.)
Try the AKG712 PRO. I admit, I'm an AKG fan. 
I don't like Sennheiser. Too expensive for what it offers.
I don't like Sennheiser. Too expensive for what it offers.
I am fine with my K701.
Compared to the Focal Elear briefly and did not find it lacking.
That stopped me from the temptation to buy a pair of Focal Clear.
You need a powerful desktop amp (like the DAO SE), and maybe add the 6kHz notch (personal taste).
K712 | DIY-Audio-Heaven
Once owned the HD25 aluminium. Needed (and still need) one for travelling.
Did not like the sound; not neutral to me. So sold it.
For travelling, I now have a MH30.
Nice built mechanically, sounds way too bass heavy.
But once modified with a -8dB in-line filter in the cable, it sounds really nice to me.
For testing amps, I use a Senn HD250 Linear for 600R (2nd hand from ebay).
And then a Superlux HD662 Evo for 30R.
The HD662 is a steal.
Superlux HD662 EVO im Test bei kopfhoerer.de
Did the mod as per diyaudioheaven, plus a 9kHz notch.
HD662-EVO | DIY-Audio-Heaven
Will give any expensive phones a run for their money.
Cheers,
Patrick
.
Compared to the Focal Elear briefly and did not find it lacking.
That stopped me from the temptation to buy a pair of Focal Clear.
You need a powerful desktop amp (like the DAO SE), and maybe add the 6kHz notch (personal taste).
K712 | DIY-Audio-Heaven
Once owned the HD25 aluminium. Needed (and still need) one for travelling.
Did not like the sound; not neutral to me. So sold it.
For travelling, I now have a MH30.
Nice built mechanically, sounds way too bass heavy.
But once modified with a -8dB in-line filter in the cable, it sounds really nice to me.
For testing amps, I use a Senn HD250 Linear for 600R (2nd hand from ebay).
And then a Superlux HD662 Evo for 30R.
The HD662 is a steal.
Superlux HD662 EVO im Test bei kopfhoerer.de
Did the mod as per diyaudioheaven, plus a 9kHz notch.
HD662-EVO | DIY-Audio-Heaven
Will give any expensive phones a run for their money.
Cheers,
Patrick
.
Attachments
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Finished and listened with HD600. I feel that the instrument and lead singer are relatively large and very close, like being in a Jazz Club.
Yes, the HD600 have a characteristic close, warm, intimate presentation. The AKG 701/2 are more airy and spacious, but colder.
My Shure SRH940s arrived today, I must say they are a pleasant surprise. They seem to more power hungry than my other headphones, being rather dark and a bit woolly until being fed by something with a little bite - like the Sapphire. Then, wow, do they really light up! Excellent dynamics and timbral accuracy. Bass frequencies roll off slightly prematurely, presumably a design tradeoff to damp out closed-back boominess, but yeah, overall very nice. I immediately liked them much more than the MDR1As.
My Shure SRH940s arrived today, I must say they are a pleasant surprise. They seem to more power hungry than my other headphones, being rather dark and a bit woolly until being fed by something with a little bite - like the Sapphire. Then, wow, do they really light up! Excellent dynamics and timbral accuracy. Bass frequencies roll off slightly prematurely, presumably a design tradeoff to damp out closed-back boominess, but yeah, overall very nice. I immediately liked them much more than the MDR1As.
If you believe in measurements, they have a 10dB peak at 10kHz.
Shure SRH940 im Test bei kopfhoerer.de
Maybe worth considering a notch.
Patrick
Shure SRH940 im Test bei kopfhoerer.de
Maybe worth considering a notch.
Patrick
Attachments
Hi there Richard, about open-back headphones reccomendations I would reccomend you to try the HD560s, if possible try them at any hi-fi store. I never heard the HD600 but in the recent years I have noticed that they are still loved more from the old owners that are used to its sound then new ones, so if you want to try something a bit different I think you should give them a try.
I have a pair of AKG K712PRO and a pair of HD560S and I love them both for one main reason. They are pretty different in everything soundwise. So if you're looking for something not too far from HD600 I don't think that other brands would be the best for you, you may want to get a new pair of HD600 or something in their lineup.
BUT if you want to try a different sound signature, then I think that you should try new headphones at any well stocked hi-fi store since you may agree that audio is a subjective topic and what someone else may like you may hate.
I have a pair of AKG K712PRO and a pair of HD560S and I love them both for one main reason. They are pretty different in everything soundwise. So if you're looking for something not too far from HD600 I don't think that other brands would be the best for you, you may want to get a new pair of HD600 or something in their lineup.
BUT if you want to try a different sound signature, then I think that you should try new headphones at any well stocked hi-fi store since you may agree that audio is a subjective topic and what someone else may like you may hate.
Hi Patrick, I can certainly believe that - bells, snare, cymbals and brass generally have a strong presence, with plenty of energy. With headphones I've learnt not to be too worried about bumpy frequency response. They are all bumpy, just that some will sound okay and some will sound not okay.