DIY Audio Demo's...

[Dubka]

Okay, I was thinking it would be great to start an audio demo section of all the gear available to build on here...
Just as a way to hear all the different Rev 1176's (without actually having to build them) or hearing the difference between a w492 and a studer 169, or how does a 2254c compare to a GSSL, valve Pultec vs. SS Pultec, etc, etc....

So then I started thinking there would have to be some kind of standard practice when making these files to make any comparisons worthwhile.  Maybe we should come up with a standard level for these too...
So anyway, I came up with using the "dry" files from the Vintage King website after seeing people do something similar over on GS.

http://www.vintageking.com/site/files/hear_the_gear/mono_eq/a-designs_em-peq.html

What do you guys reckon?  It would be great to have a larger number of these dry files too, so if anyone has any suggestions or appropriate files - speak up.  Kick, bass, room mics, electric guitar, strings, brass, female vox, etc, etc.

Even demo's of DIY against the real thing would be great.  For example, I have a 160VU (in London) if anyone wants to compare it with Abe's prototype.  Anyway, I've built the GSSL (Turbo) , 1176 Rev D (with UTC iron) and Trident 80 eq so that could be a start once the files are agreed upon.

Cheers

 

[briomusic]

I think this is a great idea!

I wonder if there is a public site to store the processed audio samples, like a photobucket for wav files....probably not so it would be up to everyone to maintain some webspace to host their samples.

A while ago, I did upload a transformer comparison for the TG-1 but I used yousendit and of course all the samples are long gone now. Instead of the vintageking recordings, I used my own audio snippet, adding an unprocessed version for reference.

 

[e.oelberg]

soundcloud.com

 

[Dubka]

Yeah, good call.
Who "owns" the forum?  Could they open a soundcloud account that we can all access? 
Like the Gmail account...

 

[Dubka]

Okay, I took the liberty of registering GroupDIY on Soundcloud..
Same username and password as the Gmail account.
If I'm stepping on anyone's toes, please let me know and I'll delete it..

If all is well, I will start by uploading the dry files from VK so people can process them with their DIY creations and upload to the account..
I think this could be a really great resource for everyone.  Hope you do too...

Cheers

 

[abechap024]

This is a great idea!

 

[Dubka]

Glad you like it Abe.

Okay, I've uploaded all the VK stuff to soundcloud.com/groupdiy if anyone wants to have a look..

Everything is 16-bit 44.1k wav so it might be an idea to stick to that format when recording any files.
Any thoughts on level matching or some kind of standard?  Normalised files?  -6db peak?

Also, we could really do with some dry files for clean and dirty electric guitars and bass if anyone has some...
I could do some DI'd bass but haven't got an amp set-up here.  Piano would be great too..

 

[abechap024]

Cool, I was able to log on and get the tracks. It says we have 120 total upload minutes...

I will upload some for CLX-VU.
and then others on my take on the PRR-176 tube vari-mu - (I am planning on some PCBS soon

We should probably try to document our settings as much as possible...though it might be kind of difficult with some projects.

 

[Dubka]

Excellent!

Yeah, I totally agree on the settings thing.  I could match your 160 files with my DBX if you like...?
You could even put front panel pics to supplement the written settings.

Maybe you can decide on the peak level if you're the first to upload some files...
Personally, I find matching levels quite important when I'm comparing processed and unprocessed sounds.

 

[abechap024]

Yes I agree - matching levels is a good thing. Lets try to match RMS? Peak? If its up to me I say we match peak with compressors...

I just fed the signals through CLX and PRR...soon to upload.

That would be awesome if you could compare it to the original 160vu. Also let me note here that I'm using opa2107s opamps instead of the original tl082's haven't really tested how this effects the sound, also this is a THAT build and just for fun I've run some stereo through them having them stereo link and matching, as closely as I could by ear, the front panel controls.

 

[shot]

How about sticking half a second of 1khz sinus on -18dbfs at the start of every test file?
When someone processes his (or her) diy stuff and matches the sinus of processed recording to be on the same level as source file's, that would be the best way to evaluate processed signal. That way there's minimum guessing on how transients and rms are handled in tested processor!

Also, maybe files should be 24bit since it's important to see the results of (very) low level signals. It's the noise that is down there, and I think it's important to be able to run precise analyses of it.

This idea is great!
Maybe in future we'll have standardized set of test sound files!
And if all diy'ers post their processed files we should be able to get a very precise evaluation of every unit done.
Wooow!!

 

[abechap024]

Yes I agree a more scientific approach will definitely yield better information on the units. I just standardized all the files to peak in wave-lab. Unfortunately the more Standardized we make it, the more things we take for granted, such as the persons reference, etc... But I'm all for it.

 

[Dubka]

I'd say peak is definitely the way to go because of the compression changing rms as you said.

Maybe I'm wrong but I think normalising might be more fool-proof than matching levels of test-tones..
It's a great idea but does everyone have accurate enough metering to make it worthwhile?

 

[Dubka]

so, what's the peak of your files Abe?

 

[abechap024]

Haha! Bummer, just realized after 4 or so tracks in, I've been uploading the wrong files! haha, yea well I am uploading the right ones now, the are matched peak wise to the peak of the control file. Most within 0.01 +/-.

Cheers,
Abe

 

[Dubka]

Okay, cool.
How did you go about matching them?

 

[abechap024]

Analyzing the peak in wavelab, then doing "change level" also in wavelab. I'm now having trouble uploading them...they will get up to 1.5mb and the restart...

 

[Dubka]

I had trouble uploading from the Dashboard..

Had to use the "upload and share" button at the top instead.

 

[Dubka]

Abe - just heard the acoustic CLX file!  Sounds great!

Just trying to figure out how I can replicate your level system in ProTools......?

 

[abechap024]

Yes...It seems that the "old skool" method is working now...probably an issue with my ISP.

I'm curious to hear a pultec a 2254 and la4....