Recent content by dunkuk

Ok the last 2 results for tonight, I did try moving the test signal level up to -3db but the interface distorted a lot, it couldnt handle it. So here are plots made with -10db and 24bit signal. I need to compare to other sound interfaces but I think this is telling me this device is not that...

Thanks Blumein, yes its not that difficult after all. You are right about 24bit I hadnt thought about that, I will try it now. 4v overloaded the inputs a lot! Was no good at all. Best THD seems to be about 0.84v (across tip and ring, 0.42v unbalanced) which is about the setting on the volume...

Hmm, I measured the voltage across the output for that last chart and it's .42VRMS across the tip and ring, so .21V ground to either of the balanced outputs. The generator is set to -10db, and the volume knob is turned fairly low now, only at about 10 o'clock. edit. Just turned the output to...

OK I can see I was using the wrong window, this is much better. I've turned averaging on as well as the chart was moving up and down a lot.

Thanks RMAA looks better in that the charts are a bit clearer, its PC only though I think, I've got a Windows Laptop I could try it on though. I managed to get the chart I was after, still not sure about the levels though. I will read that guide. Here is the latest result.

After finding no test data fro my Lexicon Alpha USB interface I thought I could try a loopback test. I'm on a Mac and REW came up as some software that would work. I spent maybe 20 minutes trying it out and got these results. What I'm confused about is how to set the levels. I've got the...

Just had a look to see whats out there, DIY Kit. https://www.ebay.co.uk/itm/47-Amp-DIY-NE5532-Hi-Fi-Headphone-Amplifier-Kit-With-Housing-DC9V-18V-New-Y3D3/113873639676?hash=item1a8365d8fc:g:NGkAAOSwlYVdaX9T...

You could also look at the ready built headphone amps sold for mobile use, the ones that amplify a mobile phone. Some of those are pretty good.

Aha, that makes sense as I made a dual mono pre amp, it was about 20 years ago so my memory is a bit hazy!

You could look at using relays if you want good quality contacts, they tend to be gold. Saying that I would think most toggle witches would not make any noticable differences to the sound. I would go for toggle swicthes / relays myself as the rotary switches seem quite a bit more flimsy in my...

Yes now I have thought about it having inputs would be quite handy as I can do things like digitise my LP records. I've been looking at this thread on Gearlslutz where people are using a standardised test on various interfaces and one of Audients ( ID22 ) comes up quite near the top of the...

Yes I agree the NE5532 is excellent, people are put off it because it cheap but thats only because they mass produce it. You do need to use a bit of gain with it though, I seem to remember it can't be used at unity gain, but thats no problem in a phono pre-amp as it has a good bit of gain.

Just to add I've been looking at the MOTU 828 Mk2 and it seems to be a high quality unit, and goes for about £150 used. The only issue is that its firewire but I think I can use a pci firewire card so that might be ok.

Here is a simple one. https://paulinthelab.blogspot.com/2014/05/riaa-phono-preamp-stripboard-layout.html

I would like to see some "vintage" recording interfaces and DACs, which for audio gear means about 10 years old :) I'm thinking EMU 0202 USB Lexicon Alpha (because I use one) Also is it possible to do this measurement with a CD player to compare? Could you burn the test tones onto a CD and...