#26 pre amp

Vinylsavor · 2013-11-30 4:54 pm

You know it is kind of frustrating to try to help with suggestions and questions, but you ignore most of it. Good luck, I'm out.

Thomas

merlin el mago · 2013-11-30 5:00 pm

Thomas please don't get angry, if tomorrow it does not work well I will follow your advice, but please let me try my own way first.

king4joy · 2013-12-01 2:40 am

....that's a lot of help..... :scratch:

Noodle88 · 2013-12-01 6:02 am

Hi !

I'm making my 26 preamp. Some photo of the PSU.

merlin el mago · 2013-12-01 11:43 am

Works

merlin el mago · 2013-12-01 11:45 am

Noodle88 said:
Hi !

I'm making my 26 preamp. Some photo of the PSU.

Very nice.

nicoch58 · 2013-12-01 12:35 pm

well merlin ,now you cannot go OT for at last one year !!! LoL

stajo · 2013-12-01 12:51 pm

Noodle88 said:
Hi !

I'm making my 26 preamp. Some photo of the PSU.

Thats some serious noodles!

I think I see 2 anode chokes, two filament chokes, one main B+ tranny, two other trannys, for filaments? Four octals. Damper diodes?

And you have volume pot and channel selector on the PSU?

/Staffan

Noodle88 · 2013-12-01 1:06 pm

stajo said:
Thats some serious noodles!

I think I see 2 anode chokes, two filament chokes, one main B+ tranny, two other trannys, for filaments? Four octals. Damper diodes?

And you have volume pot and channel selector on the PSU?

/Staffan

Planing to use LCLCLC filter for B+ filtering. Yes. 4 octal for TV damper. 2 separate filament transformer with LCL filtering. All passive filtering used.
The place of volume pot and channel selector will house vintage Weston meters.

stajo · 2013-12-01 1:21 pm

Noodle88 said:
2 separate filament transformer with LCL filtering. All passive filtering used.

Neat. What is the L values in filament chokes?

Noodle88 · 2013-12-01 1:41 pm

stajo said:
Neat. What is the L values in filament chokes?

0.7 Hy / 1A as shown in the photo.

king4joy · 2013-12-01 2:15 pm

merlin el mago said:
Works

Where was the problem please??

merlin el mago · 2013-12-01 3:27 pm

I guess a cold joint in the RCA input.

king4joy · 2013-12-02 2:28 am

merlin el mago · 2013-12-28 12:12 pm

I have to take off the 100K grid leak resistor if I want to use 50K ladder attenuator or have I to left?

Noodle88 · 2013-12-28 12:52 pm

Hi! Merlin,

Tough that you have your AVC already ?
Why putting a 50k pot ?

Cheah

merlin el mago · 2013-12-28 1:59 pm

Hi Cheah,

I only want to check if my TVC lack of bass.

Noodle88 · 2013-12-28 2:10 pm

Merlin,

Did you put your AVC at the input or output (after the opt)?

Cheah

nicoch58 · 2013-12-28 2:29 pm

with 100k in place as // 50k the total will be 33k .... not a problem if the source can drive it,btw not low ....

Brouilly · 2013-12-28 3:14 pm

Taking some time to address the grounding in my #26 preamp as there is some noise, and I got some interesting results with the frequency response.

There is a large peak at about 70KHz. If possible it would be great to get some insight on what might be causeing the instability. Has anyone else seen similar results...?

Setup is very simple - filament bias, LL1660 output

Thanks

#26 pre amp

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