Balanced preamp needed

[hamradioman]

I'm looking for a preamp that has one pair of balanced inputs and one pair of balanced outputs, as well as the usual RCA I/Os. Most importantly, it has to be CHEAP! Does anyone here know of a kit that has these features? Due to the extra long cable runs I am forced to deal with, I am currently using a DJ mixer. It has all the right features but I know I can do better. I have already shopped around for a pre that will work for my application, both new and used and I have learned that anything new is going to cost big money and anything used will be of questionable condition. Surely there must be something out there that will fit the bill. Any ideas?

Thanks in advance.
R.

 

[spaceistheplace]

Search BPBP

Or I think Doug self’s new preamp is balanced?

Of course you can build Salas’ offerings as balanced.

 

[hamradioman]

Thank you for the reply.
I have never heard of these items or people you mentioned.
Who are they? How do I get in touch with them?
Any help will be appreciated.

 

[Carl_Huff]

I'm looking for a preamp that has one pair of balanced inputs and one pair of balanced outputs, as well as the usual RCA I/Os. Most importantly, it has to be CHEAP! Does anyone here know of a kit that has these features? Due to the extra long cable runs I am forced to deal with, I am currently using a DJ mixer. It has all the right features but I know I can do better. I have already shopped around for a pre that will work for my application, both new and used and I have learned that anything new is going to cost big money and anything used will be of questionable condition. Surely there must be something out there that will fit the bill. Any ideas?

Thanks in advance.
R.

This one is balanced IN/OUT and does RC unbalanced as well. It is based on a design by Douglas Self.

Doug Self Preamp from Linear Audio #5

 

[hamradioman]

Follow-up -
And what is BPBP???

 

[motronix]

For what do you need Balanced input to Balanced Output?
most need Balanced to Unbalanced or Unbalanced to Balanced
also what do you need in this Pre amplifier? just drive flat I/O?

 

[hamradioman]

I need balanced inputs because one of my components has balanced outputs. I need the balanced outputs to drive amplified speakers which are located in another room. I need the RCA inputs because I will feeding this system primarily with a Mac Mini based music server. To do this I will need to find some sort of USB to RCA interface box which I do not have yet.
Rick.

 

[MAAC0]

One of Your components has balanced outputs, Connect hot & ground only. Leave cold floating.
Depending on distance, a couple of meters RCA cable work fine. Shunt cold & Ground at the speaker input.

 

[wcwc]

Check out Neurochrome Audio: High performance DIY audio circuits.. With a That driver board, a That receiver board, and a case you could do what you are looking to do.

 

[leadbelly]

I'm with MAAC0. If you want CHEAP, as you said, just make some custom cables. Forget the balanced preamp.

 

[hamradioman]

What about the 40 foot plus run to the amplified speakers? I tried RCA cables and the noise was horrible. The guy across the street is a CBer. His radio is a total splatter-box. I used to be able to listen to his end of his conversations over my Toaster! Until I showed him what 1200 watts of RF energy can do to his TV reception.
This is completely legal for me BTW....
He got his radio repaired.

 

[leadbelly]

1) the hum might be from a ground loop, so you should probably investigate that 1st

2) if a balanced interconnect is the answer, you can convert the unbalanced output to balanced with just a few passive components: the CHEAP you asked for

 

[spaceistheplace]

Follow-up -
And what is BPBP???

Bruno Putzeys Bapanced Preamp.

Use the forum search function

 

[spaceistheplace]

Re Cheap:

How cheap?

 

[hamradioman]

How cheap? Well, I'm thinking low to mid three figures Canadian.
I have looked at the commercially available preamps and the cheapest I have found is the Rotel RC-1570. The local dealer has some for sale at $1000 + tax.


Now, having read all the posts in this thread, I realise I can live without the balanced inputs. BUT, the long cable runs to the speakers still demand XLR cables.


I have a sheet metal brake, a well equipped workshop, I can solder and I can read schematics and instructions.
Surely this can't be THAT difficult.....

 

[spaceistheplace]

You can just about any of these options with all kinds of bells and whistles.

I’d go with Doug Selfs design if you want a completed concept. I think the DS design has phono?

What I would personally do is a Salas DCG3 or DCB1 (depending on gain needs) balanced and paired with a Maya R2R which I can control from a smart phone app.

Member TeaBag and TVicol have kits of each, making life easier.

 

[Carl_Huff]

Doug Self Preamplifier Kit

The Doug Self design that I posted earlier does NOT include a phono preamp for vinyl. It fits in a 1U case. Doug Self Preamp from Linear Audio #5

I do have a few built PCBs lying about that I'd make you a deal price on if you wanted save the time to build. It has been a popular project.

An externally hosted image should be here but it was not working when we last tested it.

 

[spaceistheplace]

Sorry for misinformation.

The DS preamp above that Carl mentioned will do the OP very well.

 

[hamradioman]

I checked the links. Very interesting preamp.
I have a 1RU box that I got for a tube amp project.
It just might work for this.
How does one go about buying this thing?

 

[Carl_Huff]

Doug Self Preamplifier Kit

I checked the links. Very interesting preamp.
I have a 1RU box that I got for a tube amp project.
It just might work for this.
How does one go about buying this thing?

Please check your personal messages. There should be one from me.