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Dallas, Texas, United States
Cline Analog

Wednesday, April 25, 2012

Two new turntable builds in progress!

I'm excited to announce that I've have begun two new turntable builds.  One is an Acoustic Research (AR) XB which will be given an updated arm, Brazilian cherry frame, a few minor tweaks, and a lot of cleaning.  The other will be a combination of Thorens motor and platter, a custom after-market tonearm, and a nice flamed maple slab I ran across recently.

The XB was in pretty bad shape when I got ahold of it.  I have removed all
of the mechanical and electrical parts and will be thoroughly cleaning
everything before putting it back together.

This image gives a good view of how the XB was originally constructed
from particle board and cheap laminate.  The Brazilian cherry wood will
be a welcome improvement.

The AR XB has a three point suspended sub-chassis which I will be modifying to ride on sorbothane bushings instead of the metal springs.  It will no longer be adjustable, but will retain all of the original vibration dampening and isolation properties.  The weakness of the original XB is that over time the springs wore out and caused the suspension to sag creating an overall "mushy" experience.  The original tonearm is being replaced by a much newer AR tonearm from one of their "The Turntable" models.

I'm really impressed by this wood.  Nice grain and color!
(It's been lightly coated with mineral spirits here to show
off what it can look like when finished.)

Initial frame cutting done.  It looks better already.

The other turntable is a fully custom build that will be very similar to the Thorens TD-316 that I rebuilt last year and use daily.  It will retain the electrical system, motor, and platter from a Thorens TD-150, with custom isolation and dampening, and then be given an Acos Lustre GST-1 tonearm. 

This flamed maple slab is 33"x15"x1" so I'll be able to select
the most attractive 13x16 portion of it for this turntable.
A closeup view of a section of the flamed effect that attracted me to this piece.

I've been waiting for an opportunity to use this arm in a build and am excited about the aesthetics and performance that it will bring to my new turntable.

This photo and the one below are from Audio Andromeda.  Check out their
blog.  It features all kinds of interesting audio gear.

More to come as these two turntables progress.

Wednesday, April 4, 2012

Austin Vintage Audio Phono Preamp


I had been thinking for some time that the Dynaco PAS2 I was using - particularly the phono stage - was the weak link in my audio system.  My setup includes the Maple Thorens TD-316 that I built last year, which has been upgraded to include an Origin Live Onyx tonearm with a Dynavector 20x (HOMC) cartridge.  I had also improved the Dynaco by adding new, original circuit pcb's, upgraded i/o and selector switch, and an Alps Blue Velvet volume control.  I then performed Curcio Audio's RIAA correction to the phono stage and bypassed the tone controls to clean up the signal, but I was just not satisfied.  So I commissioned my buddy Andrew Draper of Austin Vintage Audio to build a new custom phono preamp for me. 

He had already built my power amp based on an old RCA 6V6 console amp, and we talk about speakers and other components on a regular basis, so he was familiar enough with my system to be able to build just the right phono pre.

"This pre features (2) 6DJ8, (2) 12 AT7, and a 6by5 rectifier tubes. All stages are
actively loaded using current sources. A passive, feedback free RIAA filter fed 
by a 
cathode follower is used for equalization. The power supply is tube rectified
and choke filtered. Output impedance is low enough to drive any power amp.
What does all this mean? Beautifully detailed, accurate, warm, non fatiguing
music from sweet vinyl records.

I picked up the AVA Pre about 3 weeks ago and hooked it up between the Thorens and my amp and, after a good listening and break in period, I am immensely pleased with the richness and dynamics of what I hear.  Finally I have a matched system that delivers the kind of musical listening experience that I have been searching for.

The Guts!

Andrew kept it simple for me on this pre, but he tells me he could easily add additional
inputs and a selector switch, along with a slight modification to the circuit to make this a
full-functioning preamp capable of handling multiple input sources.
Take a look at the Austin Vintage Audio Facebook page for some information on their other projects.

My 6V6 power amp built by Andrew Draper.

The schematic for the 6V6.

Thanks for taking some time to check out Austin Vintage Audio.  I am a huge fan, as you can probably tell.