Redd Info

[rotation]

Hi!
After the New Year (Happy New Year to all of you!) i will be making 3 tube preamps for my own use. I need them for dynamic and condenser mics.
For now (after lots of search) the best candidat is Redd 47. I never heard original one, but lots of people says it's very nice and not expensive to build.

Schematic i found is this: http://img56.photobucket.com/albums/v172/gyraf/REDD47.gif
Is it correct? Do i need a special PSU or i can just use "normal", regulated?

Some people said that Cinemag input transformers sound good for this pre. Can anyone confirm this or tell what else can be used? Cinemag is expensive for me, but if it sounds good i will go for it.

I'm serious on this and already have money for parts, that's why i will be thankfull for any help, comments, schematics..

Thanks!
Miha

 

[CJ]

Unregulated is fine.
Cinemag input iron....er.....well.....Winston was getting some custome stuff from Cinemag, so I do not know if any of the shelf items will be as good, but I would not worry, just get a 1:5 or 1:7, I forget which ratio he recomends, but the sound should not be that different regardless.

 

[rotation]

Ok, thanks. I got the scheme and know which transformer i should use.
But i have problems understanding input attenuator..Can you explain how to wire it and which switch should be used?
Thanks!
Miha

 

[craigmorris74]

CMMI-7C

 

[rotation]

Thanks. What about in attenuator. I have scheme, but don't understand even what kind of switch i should use. Can anybody help me with this?

 

[craigmorris74]

Looks like a 3 postion single pole switch. Any single pole switch with at least 3 positions would work, though.

 

[Kid Squid]

what model O/P transformer ?

:thumb:

 

[Gus]

Lets think
someone makes money selling this and helps the lab with a schematic and posts in the past.

Now someone wants information to build a clone of a clone

 

[craigmorris74]

I've read where Sowter will wind a 9050 7:1 for this preamp.

 

[CJ]

Those darn EMI guys, I wish they would get un stuck from their time warp.
They are still worried about people building 60's technology, just becaus the "guys" used it, even tough the "guys" did not think very highly of this equipment.
(The US was way ahead, thanks to Dowd and others.)

EMI:
"Oh, we changed a lead on the cathode. Top Secret!. We will sue anybody who makes a two stage mic pre!"


I walked over to the Abbey Road Studios at AES.
Jeez, what a bunch of hooligans!
Looked more like a rugby team rather than a audio company.
I bet they were the guys who beat up Winston.


Just wait, suckers! :shock:

Anyway, you don't need a ton of info, you know the iron, shop carefully for tubes, and you will have a nice, clean, simple mic pre.

 

[Kid Squid]

Looked more like a rugby team rather than a audio company.
I bet they were the guys who beat up Winston.

I wouldn't be surprised :wink:

 

[rotation]

Ok, thanks. I have all needed info. The only unclear tning is the input attenuator. Someone will send me the wiring diagram, so i will bve fine.
I dont' understand why people are having problems if i'm copying preamp like this. Design is not a secret, it's similar to thousands of preamps from that time...
Miha

 

[CJ]

It's funny, isn't it?
Look at Ollie, takes all the prints home from a defunct company, and starts his own company with zero hassles. And Telefunken/ Siemens, I mean, not exactly a small company.
Heck, Siemens is still around today, although the guy I know who works there does not like it much. What else is new.
Heck, they started the whole theing anyway, the EF86/EF804s thing, the two stage pre with feedback, I mean who rips who around here?

I would just use mic type and placement fir atten.
I get so upsey when I see resistors in front of beautioful iron, where the guy spent all that money to keep the dcr low (nickel core).

Du hast eine leiterhousen, Frans? :wink:

 

[King_Cruiser]

I have the Redd 37, 43, 47 and 51 in pdf form.

Interested parties should submit an email to


[email protected]

 

[rotation]

[quote author="CJ"]

I would just use mic type and placement fir atten.
I get so upsey when I see resistors in front of beautioful iron, where the guy spent all that money to keep the dcr low (nickel core).

[/quote]

Do you mean taking the input attenuator (or part of it) away? I was thinking of this and someone suggested to do so..
Is it necessary to have that att. at the input if i use it only for a microphone? If i want line-in, how much of att. in dB do i need?
Miha

 

[solder_city]

king cruiser, are those actual diagrams or just the emi 'description' sheets? i have seen pdfs of the latter and theyre cool to read but you couldnt build a circuit from them.

 

[rotation]

There are schems around here if you search..I found two, first is for line amp, second for mic amp. You can also find other with some transistors added.
Miha

 

[volta]

Did Winston ever post a schematic for the DI input on the REDD?
Does anyone know if it is a transformer or just a resistor network?

 

[rotation]

I wanted to ask the same thing right now...

Btw, i talked to Brian Sowter about the input transformer. They have one for about 100 euros and he told me they followed the specifications when making them and that it should be as good as original or even better. For now no one heard it, but Brian says he will get report from costumer who bought it very soon.
I will buy it in a week or something, can't resist :grin: