1

Topic: Custom pre-amp for Sony PCM-D50

Hi, I bought Sony's PCM-D50 mainly to record birdsong. Putting aside the lack of xlr balanced inputs, a rather noisy mic pre-amp and poorly backlit display, I think it is a remarkable piece of kit.

With the first point in mind I looked at buying Sony's xlr-1 interface, but decided against parting with the best part of 260 quid for what amounts to a couple of "audio transformers in a box" plus I didn't fancy my chances with the noisy internal mic pre-amp. However, switched to line input, the D50 is virtually noise free and with this in mind, my attention turned towards making an external pre-amp.

I remembered reading the impressive spec for Analogue devices' SSM2019 self contained pre-amp ic's and with this in mind I set to work. The SSM2019 only requires a few external components to  function, obtaining an adequate +/-  15v power supply from 4 AA batteries was realised using a dc to dc converter. With all of this housed in a suitable case (not unlike the xlr-1) hey presto a virually noise free mic pre-amp! I could have added phantom, but as I'm using dynamic mics (no noisy, exaggerated hf response electret mics here) Woah !  it was not necessary. This also allowed direct input coupling.

The net result is virtually hiss free recordings. I have not measured the signal to noise ratio , as it isn't an issue with this set up !

I can provide extra info if required. Cheers.  Gordon.

2

Re: Custom pre-amp for Sony PCM-D50

Gordon, I would be interested in seeing your schematic and some shots of this!

I am fairly satisfied with the D50 for voice work with a Sennheiser ME66/K6 combo.  That has a battery so it doesn't need phantom.

I have a single channel Shure FP-23 portable pre-amp.  Again, fine for voice and more even with a dynamic mic like the ElectroVoice 635A.  I haven't tried it for birding.

Most people on this forum don't need "noiseless."  I think for Soundslides you really just want to make sure you don't have hiss like you find with lower end digital recorders.  But if you can point us to a link where you have an example of what it can do...that would be fun!

Cheers...

3

Re: Custom pre-amp for Sony PCM-D50

I will post some photos (not sure if this forum allows that) and a little later schematics.
I could always e-mail direct if necessary.
                                        I'll keep you posted.   Cheers.

4 (edited by Gordon 2009-03-09 09:23:08)

Re: Custom pre-amp for Sony PCM-D50

This topic is now continuing here ,with photos and audio samples.  http://forums.oreilly.com/content/Audio … m-Pre-amp/       Thanks. Gordon.