Downbeat Studio

10/08/2024

FOR SALE: $1100 shipped

This was a fun project. Repurposed a Gates M3625 Gain Set enclosure into a Gates SA-70 preamp. Tried to keep as much of the original enclosure as possible.

For the transformers we have a Jensen JT-115K on the input and Edcor on the output. Tubes are NOS RCA 6C5 and a JAN 5693 (high end substitute for 6SJ7). Inside we’ve got all new components and NOS vintage caps in the signal path, including a Soviet paper in oil cap for the output.

Gates VU meter and vintage k***s. Upper left switches are a phase, insert pad control and VU range. Controls are a Daven stepped attenuator for the pad, variable gain and feedback controls and a 6 stepped bass control that switches the caps in the feedback loop. The feedback and bass control offer subtle changes to the frequency response. There is also a DI.

External tube rectified power supply for lowest noise possible.

Great table top SA70 preamp!

09/06/2024

For Sale: $800 shipped in US

This is a new build for us. You’re looking at a Langevin 5116B circuit leveraging a UTC CG-134 on the input and Edcor push-pull output transformer. NOS GE 12BH7A and Mullard 12AX7 tubes. Solid state power supply.

Backlit VU meter with controls for stepped input pad (-40/-30/-20/0), variable gain and meter kill switch.

These are great sounding preamps and have heavy 2nd harmonic vibes. The pad allows for line level signals to be passed through the unit to add “color.” The variable gain is controlling the resistance in the feedback loop so you will notice a low end bump with lower gain and more flat frequency response at higher gain. You can dial in unique sounds by playing with the pad and gain control on your sources.

Unit comes with power cable.

The faceplate is custom painted in black metallic with gold spray over and drips. Sealed up nice with a few layers of polyurethane.

Message with questions or to purchase.

06/10/2024

I was finally able to find time this week to install the CAPI ACA and Booster board. There were a few items to take into consideration with changing the master summing circuit: - The MCI has 10K summing resistors and the CAPI ACA is setup for 47K summing resistors. Therefore I had to adjust the feedback resistor and corresponding capacitor for the 10K resistors....

I was finally able to find time this week to install the CAPI ACA and Booster board. There were a few items to take into consideration with changing the master summing circuit:- The MCI has 10K sum…

05/29/2024

About a year back, I acquired an MCI JH-618 console from Reverb to replace my custom small-format Quad Eight summing mixer (pictured below). My aim was to find a unit with enhanced routing capabilities, inline mic preamps, and EQ. I had been reminiscing about our previous console, the Sony MXP-3036. The JH-618 offered many similar features but in a more compact design....

About a year back, I acquired an MCI JH-618 console from Reverb to replace my custom small-format Quad Eight summing mixer (pictured below). My aim was to find a unit with enhanced routing capabili…

04/20/2024

FOR SALE: $375 shipped in USA

Here is another passive/active Wolfbox style transformer and tube DI.

This DI is unique in that it offers a traditional passive “Wolfbox” DI path as well as a tube DI path with a flip of the switch on the front panel. This allows the unit the have two unique paths with different sonic characteristics in one box. The tube path leverages a NOS GE General Electric 12AU7 running as a starved plate cathode follower. This adds additional harmonic distortion to the signal and sounds awesome on a variety of instruments. Gain of tube path is a variable control on the front panel and offers roughly 10db of additional gain. Both the passive and active signal paths pass through the ADC transformer.

This unit leverages vintage NOS Cornell Dubilier capacitors and a Russian paper in oil output capacitor for the tube path. Ground lift switch on rear.

Built into an aluminum grey Bud box with handle. 12VDC power supply is included.

04/11/2024

Here we have a Gates SA-70 with additional controls, DI and VU meter. FOR SALE: $1200 shipped in US

We got new old stock RCA tubes; 5693 (6SJ7), 6C5 & 6X5GT. The 5693 is a 10,000 hour life version of the 6SJ7 which replaces the 6J7 in this circuit. Plus it’s a cool red color. Hammond 808 input and ADC A14421 output transformers. Switchable backlit VU meter. Combination of new stock and new old stock parts. Output capacitor is a Russian paper in oil type.

Controls across the front are switchable input pad, gain, negative feedback control and bass control. The bass control switches different capacitor values into the feedback path. The negative feedback control provides some nice variation in bass/treble frequency response by changing the resistance value in the feedback path.

Build into a Hammond rack enclosure. Has blue hammered finish with gold speckle on the faceplate. Provides roughly 45-50 db of sweet sweet tube gain. Lots of color and vibe.

04/05/2024

Completed this Altec 436 / RS124 compressor. It’s for sale: $1200 + shipping. It’s built into a repurposed 3U rack enclosure. The face plate has been repainted black hammertone with gray speckle.

The unit has balance controls, variable input/output control, switchable attack and release (every other step has the hold function). NOS RCA and GE tubes, Carnhill input and UTM output transformers. Also was able to sneak in some remaining NOS film caps.

Message if you are interested.

03/26/2024

Nice auction hall that arrived on a pallet yesterday. Spent yesterday and today organizing. Lots of Allen Bradley carbon comp resistors, caps, transfers and miscellaneous parts. Will be listing a bunch over the next few days on eBay.

03/06/2024

FOR SALE: $875 + shipping

You’re looking at an RCA BC-6 program amplifier converted to a mic preamp inside a repurposed Collins 3U enclosure. That’s a mouthful.

Awesome sounding mic preamp featuring a 12AX7 and two 12AU7s and original RCA input and output transformers. 6X5 tube rectified power supply with brand new power transformer and all new power supply components.

Gives a little over 45db of gain. Front panel controls; stepped input pad (-40/-30/-20/0), variable gain, DI, backlit switches for power and VU meter. Meter is not backlit. All the vintage Sprague caps on preamp test good, so I kept them. Replaced the electrolytic.

Front panel has been refinished in a light blue hammered paint with black hammered accents around the k***s and switches.

Great sounding preamp ready for many years of use.

02/25/2024

This is the second time I’ve done this build. It’s Wolfbox style passive transformer and tube DI combo.

It offers a traditional passive “Wolfbox” DI path as well as a tube DI path with a flip of the switch on the front panel. This allows the unit the have two unique paths with different sonic characteristics in one box. The tube path leverages a vintage GE 12AU7 running as a starved plate small gain/cathode follower. This adds additional harmonic distortion to the signal and sounds awesome on a variety of instruments. Gain of tube path is a variable control on the front panel and offers roughly 10db of additional gain. Both signal paths pass through the ADC transformer.

The DI is housed in a new old stock Archer Slope Metal Cabinet 10 1/2 x 7 7/8 x 1 5/16 F / 3 1/4” aluminum enclosure with custom blue hammered paint finish.

This one is already sold.

02/10/2024

FOR SALE: $325 + shipping

Here we have another Wolfbox style transformer based DI. Leverages a new old stock ADC milspec transformer. Really love the sound of these transformers.

Packed into a cool Hammond amp top enclosure with chunky switches.

Message us if you’re interested.