Building First Preamp HELP

[Binski99]

Hi guys I want to build a clone of a Shure M60 preamp. Heres the link to the schematic. http://www.shure.com/idc/groups/publ...pro_m60_ug.pdf

This is the first tube build I have done, but I feel it is a good place to start. I have worked on tube amps before specifically my Dynaco SCA-35 which I restored.

I need some help finding the right transformer. What do you think the best option would be.

Also why are the center taps of the secondary and filament connected?

Should I ground the chassis to earth with a grounded plug? Or stick with a standard ungrounded plug?

One more thing I know that this was built for making long runs with turntables but will it work with line levels? If not is their a basic passive RIAA circuit I can add to make it a phono preamp?

[Eli Duttman]

What are your sources? What sort of power amps do you plan on using?

[Binski99]

Originally Posted by Eli Duttman

What are your sources? What sort of power amps do you plan on using?

Well this is weird for some reason my post is no longer their but I basically wanted to clone a Shure M60 http://www.shure.com/idc/groups/publ...pro_m60_ug.pdf and add a volume control and modify it for line levels. It is made to make up for line loss in long runs for turntables. Or instead add a passive RIAA circuit and make it a phono preamp.

I am open for other suggestions on other preamps. I would be using phono and line inputs.

[Eli Duttman]

A phono preamp is a difficult project. It's DEFINITELY not the sort of thing to tackle 1st. OTOH, a line stage is an ideal 1st project. What sort of drive voltage do your power amps require? Those numbers will indicate whether or not line stage gain is needed.

[Binski99]

Originally Posted by Eli Duttman

A phono preamp is a difficult project. It's DEFINITELY not the sort of thing to tackle 1st. OTOH, a line stage is an ideal 1st project. What sort of drive voltage do your power amps require? Those numbers will indicate whether or not line stage gain is needed.

I'm really not sure what the drive voltage has to be. The particular amp is technically an integrated amp it has one aux and one phono (ceramic) input. It is also an amp that I cannot find any info on. It has separate volume controls for each channel so I want to use it as a power amp and have a preamp that would be used to control volume and source. I guess maybe an input selector with a tube buffer might be the best idea. I want some sort of buffer for my digital sources. But their would also have to be a volume control somewhere.

[DF96]

That preamp is a peculiar design for a very specific purpose. It cannot be modded into becoming a line stage or a phono preamp.

You need to decide what you want to do (in engineering terms e.g. levels, gains), then find a circuit which does it.