Threshold fet ten/pc schematics

[audiogod]

I have a threshold phono pre with a bad hum problem, and my tech needs the schematic for it to be fixed. I would really appreciate some help in getting it asap. Thanks.

 

[aht]

Following address can help you a little bit

http://www.aht.8m.net/AHT DIFFETO DELUXE/DIFFETO DELUXE.htm


My first project is Threshold Fet-10 in a new name "Diffeto Deluxe"

 

[jan.didden]

Looks like a great project, well executed. Of course I couldn't read it. And your site throws up a lot of very annoying and intrusive pop-ups. One time only..

Jan Didden

 

[aht]

sorry with another language

my website has created in Thailand sorry with Thai language. threshold Fet-10 has an easy designed and it operated in a following method.

1.In put with differential J-fet and ccs by resistor
2.Second stage with common collectorfor for matcing high to low impedance with 1 transistor run with class-a
3.Out put with common emitter in 1 transistor run with class-a
4.Schematic coming soon

Thanks

AHT

 

[aht]

File for line amp

Nice & Easy

 

[commstech]

Re: File for line amp

Nice & Easy

Sawadee Kraap Pee AHT,
Values of C5 and R15 overlaps in the circuit. may i know what is the value? What is the trimpot R11 for? What adjustments to i make to get what readings?


Kaup Koon Kraap.

🙂

 

[SkyChu]

Excuse me ! Why I don't see the RIAA network in your schematic ?

 

[aht]

Ok...following value

62pF & 100K every value you can change for the best result. If anybody use circuitmaker2000 can email to me for a simulated file. My new project is AlephX100 in another patent of Passlabs + Aleph P1.7 preamplifier if you want some pcb files can mail to me too.

 

[aht]

comimg soon

riaa coming soon. Now i build AlephX100 and use fet-10 for preamp it's sound so good and better than Aleph P1.7 (In my mine)

 

[commstech]

I have trouble obtaining 2N4393 over here. Is PMBF4393 an equivalent? if not, can anyone advise on a substitute?

 

[aht]

Substitue

2sk170*2 / 2sk389*1 can substitue them.
And I hope you success for this schematic. Anybody who have some pcbs or photo of ono or xono phono preamp please send your idea to me forstuding. Now I already have pearl phono pcb for exchange with other pcb.

 

[Elso Kwak]

Re: File for line amp

Nice & Easy

Hi aht,
Are you sure it is as simple as that?
😕

 

[aht]

following address

http://www.aht.8m.net/AHT DIFFETO DELUXE/DIFFETO DELUXE.htm

The other schematic is regulate power supply & muting output relay & volume control

 

[commstech]

Hi AHT,
Thank u for answering my queries so far. What type of regulation u used for this preamp?

 

[aht]

Type of psu

Same same pearl phono because it's also use j-fet circuit

 

[SkyChu]

Hi Aht,

I've checked the FET series pre-amp lists from Threshold web.

FET-1 (two series) Stereo Preamplifier (1981-85)
FET-2 (two series) Stereo Preamplifier (1981-85)
FET-9 Stereo Preamplifier with Phone Stage (1986-89)
FET-10Pc Stereo Phone Gain Stage (1986-89)
FET-10HL Stereo High Level Preamplifier (1986-89)
FET-9e Stereo Preamplifier with Phone Stage (1990-94)
FET-10Pe Stereo Phone Gain Stage (1990-98)
FET-10He Stereo High Level Preamplifier (1990-94)


Which one is your line amp schematic ? because the FET-10PC don't have line amp and it isn't FET-10HL and you said "FET-10".

 

[aht]

HL HL HL

I'm sure it's HL.
You can ask any question to Nelson for sure model

 

[SkyChu]

Re: HL HL HL

I'm sure it's HL.
You can ask any question to Nelson for sure model

This is a photo of FET10/HL line nodule.

The input stage is two dual FETs diff-amp and VAG is p-ch mos-fet and output stage is mpsa42/mpsa92.

For you refer.

 

[diy guy]

maybe this link could be of help


http://get-1.jp/store/member/amp8/tr-amp/foreign/etc/etc.htm

 

[aht]

Some schematic please

Thanks Sky chu.
Can you attach sch for compair with my sch.
If your pcb is HL I think I'm wrong with model between HL & HE.

Regard

AHT