Fixing a V21 driver
Douglas as Electronics
Sep|28|2009
My August projects are finally making it to this blog. I did a gig in May with my Leslie that caused the distortion that had always been there to worsen. As I tried to move the diaphram, the sound stopped and I heard no more until I replace it with a new reproduction diaphram. A signal generator is a biggie for this type of repair. Now the Leslie sounds great but it was slow going for most of the summer.
Leslie repair
Douglas as Electronics
Sep|27|2009
Working on two leslies at the same time. Both had upper driver issues. Both are working great now. Also did the filter cap can on the 147 amp seen here. Touched up the finish with Howard’s. The church just celebrated it’s 111th anniversary. Congratulations!
Stereo tube goodness
Douglas as Electronics, Recording
Mar|15|2009
I have the stereo tube compressor working now. This was by far the hardest build I’ve tried but it is mastering studio worthy. Toroidal transformer, DC on the tube heaters, no hiss because of all the metal film resistors. Sowter iron. One channel has a kink in dual mode for now, but this thing is made for 2buss apps.
The best description I can come up with is subtle but dense. transparent and warm. You really have to sit down and try different things. I took me several hours to discover how the attack and release can have a big impact on the gain reduction. The VU meters don’t tell the full story though. My RNC’s LED meter runs circles around these meters but the VU meters are more instinctive for voice, guitar, and program material. Listen to the sample to form your own opinion, but a warning, the differences are subtle. You can’t slam something with this like a 1176 can.
The whole collection of compressors is in the first picture. varimu, VCA, and opto all represented.
piano with about 4db of compression
bass with fast attack and slow release, 5db compression
drums with highpass sidechain slow attack 2db of compression
ARP Pro Soloist
Douglas as Electronics, Music
Feb|25|2009
When an obsession makes it to your Facebook status it is time to post a blog entry about it. The ARP Pro Soloist was an early preset synthesizer made by Massachusetts company ARP. It was originally designed for the home organ market with a matching wood cabinet. The Pro was a revision which made it look more roadworthy and improved some of the switches and mechanicals. It featured single oscillator subtractive synthesis. Basic stuff even back then. It was thought that universities would buy an ARP 2500 or Moog Modular and consumers would buy the Pro Soloist.
My Switch Collection
Douglas as Electronics
Jan|14|2009
I finished wiring some switches for my latest tube compressor. Two channels of each switch. The red one is populated with Wima caps for a Hipass sidechain. In many ways this is like model plane building. Lots of zen-inducing tedium and then a result which only you will truly appreciate. It is much more fun to finish this type than worry about what you might have hooked up wrong or forgotten to do. It takes the zen out of the building.
La2a Sampledge
Douglas as Electronics
Dec|3|2008
Here are three sample. One has no compression, one is full on compression, and one is a nice level that I might use in a track. Comments appreciated.
All clips played on a ‘78 precision bass – Radial DI – Chandler TG – La2a – DAW. Clips were then normalized and converted to 256kps mp3 files.
La2a finished
Douglas as Electronics
Nov|30|2008
Hurray for holiday weekends. I finished the LA2A last night and it sounds great. other than me wiring the XLR jacks backwards, it was a successful power up. No smoke, sparks, or other setbacks. The great thing about a tube compressor is how smooth it sounds. This ain’t no VCA circuit. I’ve tried it on vocals and bass so far and both sound great through it. I did take a picture of the finished guts but like all things technical this weekend, they didn’t turn out. Only other issue is the output meter setting is not working right although I’ve heard that I’m not the only one with this issue.
L.A.(2a) Population
Douglas as Electronics
Nov|20|2008
So I finished putting everything on the la2a PCB tonight. I had to wait for a quench arc snubber and a pair of TO220 Hexfred diodes to come in. (I’m sure I lost 99 percent of you right there.)
Overall it looks great and was very easy compared to the point to point layouts I’ve done in the past. Once the case comes in it should take a couple hours to have it up and running.
La2a
Douglas as Electronics
Nov|7|2008
So I’ve taken the plunge. I’m building an La2a which is a classic tube opto-compressor. Sort of the Les Paul guitar of the studio world. The board comes from http://www.dripelectronics.com/. This is the latest revision, using Sprauge Atoms in the power section. Hopefully this will be finished in time for tracking the new Cookie Jones CD.
Why I heart valves
Douglas as Electronics
Jul|6|2008
OK. I know this is an old video, but this guy is everything that is cool about analog circuits. He has great hair, a great accent, and he waxes poetic about electrons passing through a vaccum.