Stereo LA2A Build - Part 4

[@brianmclendon1647]

Beautiful!!!!!! Amazing build man, thanks for sharing

[@ilanschulz1976]

Thanx for this series of videos.i really enjoyed watching them. You really have a very calming way of explaining stuff. recently i built gssl bus compressor myself with very little knowledge. Turned out pretty well for first-time project. I just bought a silent arts d-la2a from a guy who couldn't get it to run. In this case I left the error tracing to someone more experienced. Anyway, Thanx a lot for the videos, I'll check for more on the future. Best Ilan

[@prenticetyndall]

+ilanschulz You should have accepted the challenged and troubleshot the unit yourself! LOTS of learning opportunities in one of these, IF you have the patience. The circuitry is fairly straightforward and "simple", compared to many other units. I will have a circuit theory video coming in the near future. Cheers!

[@rectape]

Hi, nice build! Can you show us how it sounds?

[@HaHaDK]

Hi i really enjoyed all 4 videos.. i'm about to built one myself with a faceplate from Don Audio. It does not have drilled holes for "FAST/SLOW" switches or "IN/OUT TR. BYP" switches. Are these switches/holes essential/necessary for the same built you did or is it some of your own add-ons? Also: can the "IN BYP" switch that's on each corner, be connected to each other, so only 1 switch can control both channel-bypass? Again, the faceplate im ordering offers to drill one or two holes in the middle (below the "link switch") for BYPASS switch.

[@prenticetyndall]

Yes! You can modify the bypass function to operate both channels from one switch.

[@banjomakr]

Your workbench is toooo neat! :)

[@prenticetyndall]

+Marvin Walker Well, I did clear off some stuff for the video. ;)

[@MagicPocketsMusic]

Me and my friend are just planning on building a couple of these and this is by far the nicest case that i have seen for these boards, i think i read on your facebook that you got it from the uk, was wondering if you would mind pointing us in the right direction. Apologies if you mentioned it in the video and i missed it. Cheers

[@prenticetyndall]

I believe it came from Collective Cases. The front panel I received wasn't as shown on his website. He emailed me a picture of it when I requested pricing on the case.

[@prenticetyndall]

I was mistaken. Case came from DIY-Racked.com.

[@reallyniceaudio]

That case is amazing, where did you find it?

[@prenticetyndall]

I believe it came from Collective Cases. The front panel I received wasn't as shown on his website. He emailed me a picture of it when I requested pricing on the case.

[@reallyniceaudio]

Nice one! I am about to embark on this build myself and I am in the UK so i will give them a bell. I hope you will make a video demonstrating your build.

[@prenticetyndall]

I was mistaken. Case came from DIY-Racked.com.

[@reallyniceaudio]

I built mine into a 2u case which used to be a power amp in the end. Amazing sounding unit thats for sure. I really don't like the mirroring of the controls so I made my own front panel.

[@crumblenoob]

I saw some mention having the mains power switch in the middle causes some problems with hum on this case. Have you noticed it at all?

[@ExorcismMetal]

Why do you calibrate with +4dB instead of 0dB ? I mean shouldn't you be using 0.775VAC on your signal generator?

[@prenticetyndall]

+Exorcism Official Great question! Actually, saying +4dB or 0dB means nothing, since dB is a "relative" unit (or ratio) between two values. So, to answer your question, I'm using both! So, +4dBu is the SAME as 0dB VU, which is an audio signal that has an RMS value of 1.228 volts. Now, if I was referring to a 0 dBu level, that would be 0.775 volts! Confusing stuff, huh? Also, performing this calibration of the VU and GR tracking, the input signal level is not that important, as long as you can adjust the gain control to obtain a reading of 0 dB VU on the meter when looking at the audio level. Personally, I wanted a 0 dB VU signal coming in more for my own satisfaction that a) the gain controls "sit" at the proper location they should for an LA2A, and b) this would allow me to quickly judge the amplifier stages are working properly with the proper gain.

[@ExorcismMetal]

+Prentice Tyndall is dBu and dB VU the same thing?

[@prenticetyndall]

No. While the scale is the same, there is always a 4 dB difference. Example: -20 dBu equals -24 dB VU, and 14 dBu equals 10 dB VU.