Vishay resistors?

Hi,

Not much help I'm afraid but I also want to try those in a diy dac I'm building.
Nobody seems to sell these things in the UK
 
wadia-miester said:
why not try the halcro .1% procision metal ones, rather good, failing that the Craddocks, easily beats the pants of the vishays
Click to expand...

I have some Holco H8's, not bad resistors, at least they are non magnetic.
I'm currently using Rikens in the I/V which sound rather good after some burn in time
 
Andy,

The craddocks, do take a while to burn in, and can sound a touch 'forward' to begin with, (though I stick em on the cooker first!), after a week or so, they really come into their own, can use with heatsinks for greatly improved heat dissaption upto 6/8w

Leo,
why not just run a pair of very small pair of balanced isolation transformers instead of the output stage, if you like the nos sound, then this is worth a investigation and yeilds very natural results.
Afraid I can't live with it, but had fun trying
 
Tone,
I might give them a try then. Im using the Vishays in a pseudo shunt mod on the volume pot at the mo. This config seems to realy show the character of the component due to being the first item in signal path. So i could try Craddocks with ease, and it would be easy to replace.
I see there are a few flavours of craddock, any particular one to use?
 
wadia-miester said:
Andy,

The craddocks, do take a while to burn in, and can sound a touch 'forward' to begin with, (though I stick em on the cooker first!), after a week or so, they really come into their own, can use with heatsinks for greatly improved heat dissaption upto 6/8w

Leo,
why not just run a pair of very small pair of balanced isolation transformers instead of the output stage, if you like the nos sound, then this is worth a investigation and yeilds very natural results.
Afraid I can't live with it, but had fun trying
Click to expand...

I already tried transformers from Sowter but they didn't give very satisfying results.
I now use AD844 as a common base (not classic op-amp I/V implementation) with 2sk170bl as output buffers and multicap RTX coupling caps.
The offset of the dac is nulled by a j-fet.
The Rikens did sound mushy when new but improved a lot after a while.
I've not tried the Caddocks yet so I'll give them a try.
Tone, What sort of dac is used in the wadia? I've only heard the stock player
 
Leo,

depends a lot on the models, I perfer the older 1702's (I know a lot of the guys don't like these, done right they sing) to the 1704's (861's/27ix's/301's/302's) I also like the pmc 63 'k' grade. (15's /6's)
All the dac chips are in dual diff (even doubled these up extra 3 db anyone :cool: ), reciever chips, are either 8412/8414/'s and a lot of work is needed to get em right, not just the analogue & digital suppiles and grounds either ;) Have experimented with AKM's as well
The number crunching is done by PGFA's and wadia use there own spline interpolation curve (no brick wall filter).
The cmos section is very current hungry, had to uprate the N/C specs to cope with 1200ma constant draw on the 15 :eek:
Later ones still drawing well over 700ma's, lots of processing power used
They do use 4 bits to drive the digital vol control, (Though I've manage formulate a solution for this) basically its 32 times oversampled (taking into account the digimaster filter).
The output stages run 'm' & 'v' caps, quantum regs (4), our own design opamps, we use in our test rigs (rather good) and buffered in the stock unit with opa 634's they give 250ma output, great line drivers, all hard wired with 'wanky wire'
all decoupling B/g's signal has oscons, unique psu's (6 in total) for dual analogue stages, clock and cmos section as well as sevro drive.
Its good just the wadia are big :D
Tried the balanced trannies, (those trick silver wired swiss ones) humm not quite what I hope for, so we had some made with our wire and true balanced design. So people swear by them, I'll pass.
Currently working on some hard wired point to point circuit boards (amazing how much difference this makes). T.
 
Last edited by a moderator:
wadia-miester said:
Leo,

depends a lot on the models, I perfer the older 1702's (I know a lot of the guys don't like these, done right they sing) to the 1704's (861's/27ix's/301's/302's) I also like the pmc 63 'k' grade. (15's /6's)
All the dac chips are in dual diff (even doubled these up extra 3 db anyone :cool: ), reciever chips, are either 8412/8414/'s and a lot of work is needed to get em right, not just the analogue & digital suppiles and grounds either ;) Have experimented with AKM's as well
The number crunching is done by PGFA's and wadia use there own spline interpolation curve (no brick wall filter).
The cmos section is very current hungry, had to uprate the N/C specs to cope with 1200ma constant draw on the 15 :eek:
Later ones still drawing well over 700ma's, lots of processing power used
They do use 4 bits to drive the digital vol control, (Though I've manage formulate a solution for this) basically its 32 times oversampled (taking into account the digimaster filter).
The output stages run 'm' & 'v' caps, quantum regs (4), our own design opamps, we use in our test rigs (rather good) and buffered in the stock unit with opa 634's they give 250ma output, great line drivers, all hard wired with 'wanky wire'
all decoupling B/g's signal has oscons, unique psu's (6 in total) for dual analogue stages, clock and cmos section as well as sevro drive.
Its good just the wadia are big :D
Tried the balanced trannies, (those trick silver wired swiss ones) humm not quite what I hope for, so we had some made with our wire and true balanced design. So people swear by them, I'll pass.
Currently working on some hard wired point to point circuit boards (amazing how much difference this makes). T.
Click to expand...

Cheers Tone, nice bit of kit you have there:)
I agree regarding the 1702's, alot better than the 1704 by a long way, I reckon they screwed the output of the newer ones for some reason.
I've heard dacs using the pcm63's but I've never used them yet and they are becoming harder to find a supplier now they are discontinued.
Most of the supplys I use are Andys excellent super regs but I'm toying with the idea of trying nfb types next.
I also have the CS8412's but never tried the smd CS8414 yet so Idon't know how these compare, I'm still experimenting with the CS8412 for now.
Theres still a fair bit of stuff I need including some nice transformers, the UK is crap for sourcing parts.

Leo

PS I want to have a look on the website at the bottom of your posts but my internet just goes off, I've had this problem with a few other sites.
Unfortunately I'm useless with pc's:))
 
Leo,

Andy's regs are good, plus he's a genuine guy too & knows his onions
The 8412/8414 are basically indentical (pin outs are the same) save for 96khz capability.
The 8413 has a configurable internal buffer memeory read through the serial port, which can be used to buffer channel status, auxillary data &/or user data.
Those are only a few mods, a few are our little 'dodges' if you like leo.
I do like some of the charm of non o/s, but I want more (great song!)
T.
 

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