Layout / Schematic for Tube Mic Preamp with Transformer

[22uf]

Hi,
Does anybody know of any good layouts/schematics for a simple 1 channel DIY tube mic pre with transformers? I do not need phantom power.

In the circuit I want to avoid any IC chips.

For components my budget target is £100 - £200.

Is this schematic any good?
Build a tube Mic Pre: Build Your Own Two Channel Vacuum Tube Mic Preamp! | Tape Op Magazine | Longform candid interviews with music producers and audio engineers covering mixing, mastering, recording and music production.

I can’t really seem to find anything online. Ideally I want a vintage schematic, but most of all importance is that it is relatively easy to build.

[22uf]

Any ideas?

[rayma]

That circuit looks pretty good, and here are a couple of older ones.
Vacuum Tube Stereo Microphone Preamp
Shure M65 Stereo Phono Pre-Amplifier Manual | Vinyl Engine

A solid state mic preamp would be much easier to build, and more quiet, though.

[22uf]

Originally Posted by rayma

That circuit looks pretty good, and here are a couple of older ones.
Vacuum Tube Stereo Microphone Preamp
Shure M65 Stereo Phono Pre-Amplifier Manual | Vinyl Engine

A solid state mic preamp would be much easier to build, and more quiet, though.

Yes, this looks simple enough. Are there any sound clips anywhere? Is it based on anything?

[Schmitz77]

The quitness of tube phono amps is nearly irrelevant, as the most noise comes from the record surface. The noise floor of tubes is so low and their dynamic range is so high, that the LP is not the media to match with it.
Shure M65 is an all time classic.

[baudouin0]

22uF your schematic looks good and will drive balanced out. The step up is needed if you want balanced in and good noise figure from say a SM58.


OEP do a good range of suitable transformers:


https://uk.farnell.com/oep-oxford-el...150/dp/1172344

[Burnedfingers]

Originally Posted by rayma

That circuit looks pretty good, and here are a couple of older ones.
Vacuum Tube Stereo Microphone Preamp
Shure M65 Stereo Phono Pre-Amplifier Manual | Vinyl Engine

A solid state mic preamp would be much easier to build, and more quiet, though.

I would look to find a Shure I have used them in the past and they sound fine are quiet and with a re-cap will last and perform well. If your wanting to build then I like the 6AU6 mic preamp rayma posted.

[martyh]

If you want transformers the RCA MI-11241 from the BC-2B is a classic. The feedback
and low current draw make it easy on the transformer so you wont need anything as expensive as an LS27 shown in the schematic at this link. RCA BC-2B Recording Studio Console c. 1952 – Preservation Sound The schematic at the link is correct other than the cathode voltages and transformer numbers. 15K:600 is about right for the output transformer. The input transformer should be about 1:10 turns ratio to get the specified 40 dB of gain

[Kay Pirinha]

Originally Posted by Schmitz77

The quitness of tube phono amps is nearly irrelevant, as the most noise comes from the record surface. The noise floor of tubes is so low and their dynamic range is so high, that the LP is not the media to match with it.
Shure M65 is an all time classic.

Do you seriously listen to records via a microphone?

Best regards!

[HollowState]

Here's a vintage mike preamp to consider. You could build only one channel if needed and omit the phantom power. The expensive UTC transformers can be substituted as well as the tube choices.