Hi folks-
Thank you Salas for the latest build schematic.
Now I have to make a decision to either mod my existing Salas RIAA's or build a new pair....! I still have some matched jfets and leds. Looks like I'll lave to order a new set of texas precision R's for the network anyway. Where's a good source for 2SK369's?
-Kent
Thank you Salas for the latest build schematic.
Now I have to make a decision to either mod my existing Salas RIAA's or build a new pair....! I still have some matched jfets and leds. Looks like I'll lave to order a new set of texas precision R's for the network anyway. Where's a good source for 2SK369's?
-Kent
Hi Buzz
I have bought R-Cores from an eBay seller in Hong-Kong called 'Hi-Fi Spot'.
Search 'R-Core transformer'...from international sellers.
They have 100% feedback, & their R-Cores are first-rate, and not expensive even with shipping IMO.
Just make sure you get one with enough 'voltage overhead', if you know what I mean.
Thing about R-Cores is...
...they offer a FREE inbuilt RFI-filter, as the RFI can't 'jump across' between the primary & secondary, by capacitive-coupling.
Toroidals are TERRIBLE in this respect.
EI's a bit better.
R-Cores...BEST !!!
It's worth it.
They have loads of different VA's & voltages as well.
Cheers.
Si.
I have bought R-Cores from an eBay seller in Hong-Kong called 'Hi-Fi Spot'.
Search 'R-Core transformer'...from international sellers.
They have 100% feedback, & their R-Cores are first-rate, and not expensive even with shipping IMO.
Just make sure you get one with enough 'voltage overhead', if you know what I mean.
Thing about R-Cores is...
...they offer a FREE inbuilt RFI-filter, as the RFI can't 'jump across' between the primary & secondary, by capacitive-coupling.
Toroidals are TERRIBLE in this respect.
EI's a bit better.
R-Cores...BEST !!!
It's worth it.
They have loads of different VA's & voltages as well.
Cheers.
Si.
Hi Ricardo
Thanks for the Haku ( typo ? ) prose, on silver-mica & styrene.
" Powerfull snappy sound "
" Smoother highs "
Nice !
Well, we want BOTH ! at Space Egg...
...so experimentaly it is...14nF silver-mica, with 'parallel plastic' to bump-up to NIRVANA !
BOO JAH ! to that.
More news on the DIY source-resistors soon, + PICS !...
...they working well & lookin'...
... " A OK Houston... over ".
Cheers.
Si.
Thanks for the Haku ( typo ? ) prose, on silver-mica & styrene.
" Powerfull snappy sound "
" Smoother highs "
Nice !
Well, we want BOTH ! at Space Egg...
...so experimentaly it is...14nF silver-mica, with 'parallel plastic' to bump-up to NIRVANA !
BOO JAH ! to that.
More news on the DIY source-resistors soon, + PICS !...
...they working well & lookin'...
... " A OK Houston... over ".
Cheers.
Si.
Hummm cinese R-core! "voltage overhead" means poor regulation ie bad design .
Selectronic r-core is certificate njfet riaa
Buzz ,the toroid are good about radiate noise the problem is that are wideband device very bad con filter the main gremlins..the 229 are on my phono btw, EI with split design in separate box are best too
Separate box always if possible, psu diode /caps radiate noise too
Selectronic r-core is certificate njfet riaa
Buzz ,the toroid are good about radiate noise the problem is that are wideband device very bad con filter the main gremlins..the 229 are on my phono btw, EI with split design in separate box are best too
Separate box always if possible, psu diode /caps radiate noise too
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This one isn't flexible at all for IDSS. You need 11mA K369BL as it is noted. Maybe 20 pcs needed to chance on a couple of good pairs about the 11 mark.
2nd tier quality solution is the 2x K170BL 8mA example I had posted. 2 junctions and more 1/F noise, but +2dB gain. Not bad at all in the end, still not the reference design exactly.
Are you sure?
Rcores have half the primary turns on one limb and the other half on the other limb.
The secondary turns are similarly split between the two limbs.
This is an ideal way to capacitively couple the Primary to Secondary windings.
EIs that separate the Primary from the Secondary are better at reducing capacitive coupling. If I understand transformer correctly this reduction in capacitive coupling is at the cost of increased leakage inductance. You swap one for the other.
There is no "best". All are a compromise.
No. You misunderstand. A regulated supply requires a higher transformer voltage than an unregulated supply. Typically use a 12Vac transformer for a 18Vdc supply when unregulated. Use a 18Vac transformer for a "normal" regulated 18Vdc supply. A Salas Style Shunt regulator uses a 20Vac to 22Vac transformer for a 18Vdc supply due to the requirement that the CCS must never see a voltage drop of less than 5V and preferably more than 7V. This is nothing to do with "bad design" !!!
You have understood capacitive coupling properly. But best ONLY for capacitive coupling or at least for reducing that.
Another unhelpful post ?
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How would a 11mA k170 compare?
Not enough transconductance?
Maybe a 13mA or 15mA V grade?
Would a cascode solve the dissipation that ensues?
No. You misunderstand ! I mean the trafo we speak about r-core cinese not the regulate psu power like Salas shunT !
I will be taking the dual 170 for the first build, as it is a Christmas present for my brother. If i am blown away, /i will try the 369 version. The whole thing may be beyond my ability to hear and I am only building because i have built other Salas stuff and enjoy his taste. The toroid option will be used for the first build and I will look into other options for my personal build. Components are in route.
369 had noise advantage that even paralleled 170 does not have. Borberly used 4 in a row(which would be better), but all else changes. I may try BF862 with second build, just for kicks and to worry Salas
One=not enough Yfs and more hiss. 2 K170=enough+ mS, about same hiss, still not the 1/F under 300HZ quality of a 369. Caution, small IDSS changes will not let it centre properly with same resistor values around. This one is much more peculiar for total bias current feed and spare for BC560 bias. There are two branches now, the normal simplistic has one current branch. Heat builds up normally on the Fet(s), only the BJT on top gets a dissipation benefit in the folded.
369 had noise advantage that even paralleled 170 does not have. Borberly used 4 in a row(which would be better), but all else changes. I may try BF862 with second build, just for kicks and to worry Salas
He had much more capacitance also and a telescopic cascode. Different beasts.
Didnt seem like you were getting enough of a workout, lately. Ill finish my first one before reinventing the wheel
Good morning Gentelmen !
I think the point about the R-cores is...
...low-field & low P-S coupling.
Obviously, the toroids windings, are snug as a bug.
I don't see toroids as any cheaper, by any reasonable margin either.
Voltage-overhead...
...not bad design.
Just get one with enough to drop.
Some guy moaning about Chinese R-Cores in another thread...
...bought a 18v one & expected to get 18v out of it after a couple of regs...
...Dddeeeeer ?
Easily done getting too few Volts...
...having said that, you don't want too many; just to burn-up in your regs.
Beam me up Scotty....................................
Cheers.
Si.
I think the point about the R-cores is...
...low-field & low P-S coupling.
Obviously, the toroids windings, are snug as a bug.
I don't see toroids as any cheaper, by any reasonable margin either.
Voltage-overhead...
...not bad design.
Just get one with enough to drop.
Some guy moaning about Chinese R-Cores in another thread...
...bought a 18v one & expected to get 18v out of it after a couple of regs...
...Dddeeeeer ?
Easily done getting too few Volts...
...having said that, you don't want too many; just to burn-up in your regs.
Beam me up Scotty....................................
Cheers.
Si.