Anyone have any service info on this one? It was a $4000 preamp when new, and I have one here with issues. Awfully big and heavy for a preamp, and is quite seriously constructed internally.
Unit is all FET, and uses some devices that I've never heard of and can't find... UP07 and UN07 (P-chan and N-chan FET's) in a TO-126 package, besides a few more common 2SK117's and 2N5465's.
Is there perhaps a sub for these devices? Does anyone have a schematic?
Unit is all FET, and uses some devices that I've never heard of and can't find... UP07 and UN07 (P-chan and N-chan FET's) in a TO-126 package, besides a few more common 2SK117's and 2N5465's.
Is there perhaps a sub for these devices? Does anyone have a schematic?
I searched the internet for more than 1 hour
for eventual schematic, manual or technical information of the Stax CA-X preamplifier.
Stax CA-X is an 'All FET Preamp' from 1978. CA-X Pro came 1979.
It is expensive.
The closest in design idea maybe is the Borbely All FET Line and Phono preamplifiers.
The actual circuit of Stax CA-X would be interesting to know.
A bit different than Borbely, I am sure.
for eventual schematic, manual or technical information of the Stax CA-X preamplifier.
Stax CA-X is an 'All FET Preamp' from 1978. CA-X Pro came 1979.
It is expensive.
The closest in design idea maybe is the Borbely All FET Line and Phono preamplifiers.
The actual circuit of Stax CA-X would be interesting to know.
A bit different than Borbely, I am sure.
http://www.stax.co.jp/Export/History.html
1978
Dual-Mono construction all FET pre-amplifier with Super-shunt power supply CA-X
1979
Dual-Mono construction all FET pre-amplifier with Super-shunt power supply and DC type flat amplifier CA-X Pro
http://www.borbelyaudio.com/products.asp
Pre Amplifiers
EB-707/432 Low-cost All-FET MM/MC Phono Preamp
EB-703/325 All-FET Line/Headphone Amplifier
www.earsp.site40.net
UN07/UP07 are 250mW JFETs, complementary replacements are (selected) J103/K246.
A few other brands used the UN/UP devices.
(EW needs a hug and a Xmas present)
UN07/UP07 are 250mW JFETs, complementary replacements are (selected) J103/K246.
A few other brands used the UN/UP devices.
(EW needs a hug and a Xmas present)
Roar Malmin said:Jacco, I must take exception to your claim. They are MOSFETs, and not JFETs. I happen to have some of them. Furthermore, they are in a TO-126 package, whereas the 2SK246 use a TO-92 package.
Regards
Roar
I do see JFETs in the simplified schematic of the CA-X file in Jacco's link.
Click on CA-X取説
Roar Malmin said:Guys, does this look like a JFET to you?
Regards
Roar
It looks like a MOSFET.
By the way do you live in Hokksund?
Jeg bodde der i mange år før jeg flyttet til Bergen. Jeg er i Hokksund noen ganger hvert år, har en bror som bor der og en bror i Åmot.
Stinius
Roar Malmin said:You are most welcome. People who share my interests are in short supply around here.
Regards
Roar
I know that
Stein
Here is simplified diagram from CA-X.
Upper left shows an all FET discrete (op-)amplifier.
The loads are current sources for maximal gain.
The output is one complementary push-pull FET buffer.
Lower right is probably the MC phono amplifier.
With one FET buffered DC-servo feedback at 0.34 Hz
Upper left shows an all FET discrete (op-)amplifier.
The loads are current sources for maximal gain.
The output is one complementary push-pull FET buffer.
Lower right is probably the MC phono amplifier.
With one FET buffered DC-servo feedback at 0.34 Hz
Attachments
jacco,
incredibly nice (for the price).
https://www.addison-electronique.co...=up07&osCsid=8500849d616ecebafe8a55a057b43dbc
incredibly nice (for the price).
https://www.addison-electronique.co...=up07&osCsid=8500849d616ecebafe8a55a057b43dbc
https://www.addison-electronique.com/catalog/product_info.php?products_id=74876
https://www.addison-electronique.com/catalog/product_info.php?products_id=74877
$0.99 each for UN07D and UP07D
But no description.
https://www.addison-electronique.com/catalog/product_info.php?products_id=74877
$0.99 each for UN07D and UP07D
But no description.
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