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Old 27th November 2009, 03:08 PM   #551
Salas is online now Salas  Greece
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sshh more than there is on the recording on 's' in voices.
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Old 27th November 2009, 03:10 PM   #552
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Thanks Salas,

I got some 120va 15v transformers on sale at farnell so I bought them up. 14€ each, not bad!

The thing is, I can hear the clean treble extension on this thing. I can hear how quiet it is and how dynamic it is. At the same time, I don't want to overstate the sibilance I'm hearing, but it is there. I also fully realise that there is a bunch of optimisation to be done on my implementation yet - e.g. matching the input resistor to the pot, sorting out internal wiring - in particular the connectors are old, have some corrosion, and the input wiring really needs to be soldered in. The input voltage needs to be upped, and also the current through the shunt too maybe.

So theres a ways to go yet, and from what I hear so far, I think it sounds very very good. It certainly is well out in front of the regular B1. So much so, that if anyone is thinking of building a B1, then I would say skip right to the DCB1.


Fran
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Old 27th November 2009, 03:10 PM   #553
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Yes, so when Louis and Ella sing "April in Paris" you get "april in Parisssssssss"


thats an exaggeration, but you know what I mean!

Fran
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Old 27th November 2009, 03:18 PM   #554
Salas is online now Salas  Greece
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Things to watch/check out/compare for retaining smooth hf transients:

Dirty contacts.

Non shielded in/out wire, especially if silver plated copper. Compare a plain quality coax substitution effect on one input.

Proximity of transformers.

Artifacts in mains power.

Synergistic in line buffer resistors. I.e. The audio section's 220Rs and somewhat the 220Ks (560Ks if with 50K pot).

Pot quality.

Some dry soldering somewhere.

Traces of oscillation when driving some particular load / interconnects.

Mistracking due to imperfect geometry & rake angle, hard dirt & wear on needle, if the source is a TT.
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Old 27th November 2009, 03:24 PM   #555
Salas is online now Salas  Greece
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Quote:
Originally Posted by woodturner-fran View Post
Yes, so when Louis and Ella sing "April in Paris" you get "april in Parisssssssss"


thats an exaggeration, but you know what I mean!

Fran
Those Verve recordings have it a lot. Especially Louis in ''Autumn in New York''. It seems they had to sing songs pleasing their audiences both sides of the pond.

The key is to know from some systems how a recording sounds and how much it got. I prefer KNOWN headphones for that, so to avoid irregularities from amps further the chain, tweeters etc.
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Old 27th November 2009, 03:26 PM   #556
udailey is offline udailey  United States
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Thanks for the explanation guys.
Fran be careful with that 120VA inrush current.
Ri
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Old 27th November 2009, 04:19 PM   #557
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Quote:

Dirty contacts.

Non shielded in/out wire, especially if silver plated copper. Compare a plain quality coax substitution effect on one input.
thats the most likely problem in my case... will also have a look in my parts stash to see if I have any other 220R resistors. Even a different cheapo type might help if clean contacts and replacing the 220K doesn't work.


I don't expect too much problems with the inrush at 120VA, although I might need to go a little higher on the fuse to avoid nuisance blows.

More later.....


Fran
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Old 27th November 2009, 05:39 PM   #558
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Quote:
Originally Posted by woodturner-fran View Post
3. xicon metal film 1%50ppm from mouser: 273-220-RC (nothing special I know, and deinfitely not kiwame or takman!!)
Fran
I've ordered my parts from Mouser yesterday and I included some Vishay/Dale RN series that another guy recommended to me, planning to use them in the DCB1 signal path. Do you think it would be worth paying some 10-15 Euro more just to get some Takmans for this role?
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Old 27th November 2009, 05:45 PM   #559
Salas is online now Salas  Greece
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If you want to check out carbon too, why don't you look for KOA SPEER on Mouser?

http://www.koaspeer.com/resistors.asp?part=47
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Old 27th November 2009, 05:52 PM   #560
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yep I am using the KOA 1watts, and I think they sweeting up the sound.
Honestly, I am not sure I like that. It's not a huge amount, and it doesn't blur things.

Takeman's sounded a bit zingy in the original B1 circuit. IMO. I would not spend that kind of money on Takemans alone.

I think DaleRN or PRP are about as good as it gets for my taste. Clear, not mellow, not spaztic. you can always change them. The PRP offers a slight improvement in resolution, if one has very resolving equipment.
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