Coupling transformer for SE/BAL conversion

[Dadbeh]

chinese 12AU7/6922 preamp kit questions

I am building this 12AU7 tube preamp that has single ended and balanced inputs and outputs and the kit requires the use of two coupling transformers that facilitate converting a single ended signal to balanced and vice versa.

Hi End AudioResearch ARC Tube Preamplifier XLR Balanced Or RCA Input&Output,12AU7/ECC83+ECC88/6DJ8 Preamp DIY Kit-in Amplifier from Consumer Electronics on Aliexpress.com | Alibaba Group


The problem is that other than 600:600 I dont know anything about the correct part and its parameters. there is a bunch on mouser but they have different frequency range etc and it is not clear to me which one would be ideal.

 

[R Kneck]

Hi Dadbeh,
Edcor sells a 600:600 transformer
EDCOR - XSM Series

 

[Dadbeh]

Hi Dadbeh,
Edcor sells a 600:600 transformer
EDCOR - XSM Series

thank you so much. this is great and exactly what I needed.

there are a bunch of them on mouser from $5 but their frequency range is something like 300hz to 3.5 khz. this edcore is one of the few 20hz to 20khz which I'm assuming is needed here.

 

[Dadbeh]

I could use more help. I have never built a tube based kit and these are the AC requirements:

AC/6.5V/2A (±3%) _ AC/280V-0-280V/100MA (±5%) _ AC/14V/3A (±10%)

I could use some direction from someone with experience. what should i order? should it be 3 separate trannys or just one that has different winding? please advise.

 

[R Kneck]

A Hammond 270Dx transformer will get you most of the way there, 275-0-275 at 104 mA, and a 6.3volt at 3 amp winding. The 14 volt transformer I don't have a clue where to get.

 

[Dadbeh]

I already own this one: AS-1215 - 100VA 15V Transformer - AnTek Products Corp
can it be used for the 14v?

 

[Dadbeh]

 

[Dadbeh]

as for the 185v, i was thinking this one: EDCOR - XPWR009

 

[R Kneck]

Yes, the Edcor power xformer should work fine. The Antek should work also but has over twice the power capacity than was called for. Better to have too much than not enough. Is there a schematic?

 

[Dadbeh]

schematic:

Imgur: The magic of the Internet

Order already placed for the edcors.

 

[Dadbeh]

WHAT are those zener diode banks? i dont even see them in the schematic.

 

[R Kneck]

Can you post the schematic? I saw all those zeners and wondered the same thing.
Redd

 

[Dadbeh]

Can you post the schematic? I saw all those zeners and wondered the same thing.
Redd

I already did. This is the schematic:

Imgur: The magic of the Internet

 

[Dadbeh]

I broke one of these relays:

which one of these works:
DS2Y-S-DC24V Panasonic Electric Works | Relays | DigiKey

G6S-2 DC12 Omron Electronics Inc-EMC Div | Relays | DigiKey

omron:
G5V-2-DC24 Omron Electronics Inc-EMC Div | Relays | DigiKey

DS2E-S-DC24V Panasonic Electric Works | Relays | DigiKey

 

[PRR]

None of the above. The part is a 5V relay.
Golden Relays site (mostly in Korean)
Dongguan Golden Electrical Appliances Co., Ltd., in English
GC relays datasheet

 

[Dadbeh]

this schematic does not match the kit that i have.

 

[Dadbeh]