Build out a Mixing/Recording Room – Part 2

Finally, the money and time have presented themselves and I can continue the build-out of a new studio in the a basement room of a residential home.

You may review the previous blog of 4-2013
“Build out a Mixing/Recording Room – Part 1”

The owner has some specific concerns. Particularly in that “ I don’t want to hear anyone above me and I don’t want them to hear me” meaning, the rest of the family. Kind of a tall order given the fact that there is not much floor to ceiling height in this space. It is much easier to make his wishes happen when the space has a ceiling height of 10 or more feet. This space is 7′ 9”, that’s it. Bummer! Oh and did I mention, the budget is very tight. Ah!, the music business.

In deciding the best, most economical way to achieve the issue of sound transmittal between the basement room and the family room I have found that attaching drywall to the underside of the floor works pretty well. The addition of “Green Glue” works even better. As you can see in the following image there is space between the floor/ceiling joists that can be worked on.

Great Mix Recording - Studio Build Out - Ceiling No Drywall

I cut strips of 5/8” drywall of 8 foot lengths to fit in between the joists, spreading Green Glue on the drywall prior to screwing to underside of the floor. The whole idea of Green Glue in a nutshell is that by putting a layer of GG between two surfaces, the energy of noise whether its acoustical or impact is converted to heat and spread sideways to keep the energy from passing through to the other space.

Go here for info on what GG is:

One important thing about GG is that it takes awhile, time wise, to reach its full transmission stopping properties. There have been reports that as much as 3-4 months have gone by till you get the full benefits of GG.

Great Mix Recording - Studio Build Out - Ceiling With Drywall

You also need to chalk any gaps in the drywall/GG application.
Use an acoustical sealant. Not any ole’ chalk.

Great Mix Recording - Studio Build Out

Great Mix Recording - Studio Build Out - GG Application

You will also notice that there is HVAC duct work in the joist space that supplies conditioned air to the family room above this space. Another hurdle to overcome. Arrrg! This has to be dealt with as sound easily comes thru the duct work and vice versa. The best way to resolve this issue is to take down the duct work and wrap it with VERY expensive acoustical blocking material. Not going to happen.

So, next best way is to wrap the duct with a rubberized membrane that will cut down on the transmission and ringing of the sound. Still, pretty expensive. However, I found an automotive product designed for automobile interiors that will work just great for 1/3 of the cost. Ebay saves the day again!

This also needs to be done with any water waste pipes in the area.

Great Mix Recording - Studio Build Out

Great Mix Recording - Studio Build Out

Great Mix Recording - Studio Build Out

The next step is the addition of insulation stuffed between the joists. This helps even more to cut down on sound transmission by absorbing the higher frequencies. Do not “pack” it in. It needs to be relatively loose. Do not let it extend past the bottom of the joist.

The final step in the ceiling/floor issue will be to “float” the ceiling. I will discuss that in a later blog after the walls go up.
A great resource is:

Walls are just about all up.

Great Mix Recording - Studio Build Out

Great Mix Recording - Studio Build Out

Great Mix Recording - Studio Build Out

. Record . Mix . Master . Music .

1957 Fender Tweed Twin Clone Build

As I mentioned before, I had a fun time building the ’59 Bassman.
I could not leave it at that…

I have completed a build on a ’57 Twin combo amp. I really like the 30 -50 watt amps that use a push-pull, 6L6 output configuration. With this build I decided right away that I would use the Sozo premium caps, add an adjustable bias for the power tubes and a slight mod in the input section. The “front end” of the Twin is a bit different from the Bassman.

'57 Twin board

'57 Twin chassis

Each input uses ½ of 12AY7 into another 12AY before the power section. I changed ch 1’s 12AY and put in a 12DW. And put in a nice balanced gain and balanced triodes 12AX7 in the phase inverter circuit. I also used late distortion Svetlana power tubes.

Back to the ch 1 mod. So, the 12DW is an interesting tube in that ½ is a 12AU style and ½ is a 12AX style. I installed a switch so that the player can switch between the two styles of tubes to alter the gain going into the tone section. This can work extremely well with boost and distortion pedals. And left in a jumper to “jump” the ch1 signal to ch 2 and mix in a bit of “bright” sound using the standard 12AY circuit.

A side note about 12_ _ 7 tubes. The AX, AY, AU tubes have different gain structers which an amp designer can use to create how an amp will sound. The AX has a gain factor of 100 while the AU has a factor of 40. What this means is the AU will sound cleaner until it is pushed hard, and then break up. The AX style will distort faster with a different break up tone than the AU. The AY has an even different gain and current factor. Pretty neat stuff.

Anyhow to wind up the build I used Eminence Cannabis Rex speakers to deliver a nice smooth tone across the guitars frequency range. My guitar guru Kris says, this is a great amp for blues style player and sounds incredible with a boost pedal.

Again, if you are looking for a quality Tweed style amp, contact me. I would enjoy building any style for you. Or, if you have a tweed, blonde or blackface in need of repair or upgrading. Let me know.
THIS AMP IS FOR SALE! Contact me if you are interested.

'57 Twin Amp

. Record . Mix . Master . Music .

1959 Tweed Bassman – Part VI

Part 6, Tweaks

Well peeps, I finally had some extra time to finish some more tweeks on the ’59 Bassman clone.

First up I replaced the “orange drop” signal capacitors with SoZo units. These are closely modeled after the Yellow Astron and Blue Molded series of vintage capacitors. Listening before and after the SoZo units was quite revealing. The sound, after putting in the SoZo units became higher in fidelity. The high-end was nicer, more articulate. The bottom-end was tighter and a bit more beefier. Amazing!

SoZo caps

Next up, I modified the bias circuit making it adjustable. I removed the 56k resistor and replaced it with a 50k linear potentiometer wired as a rheostat. I also replaced the ground wire from pin 8 to chassis with a 1 ohm resistor to ground. This will assist you in taking readings with a voltmeter to bias the power tubes. Once you have an adjustable bias control you can really dial in your sound. I started out low in bias voltage and ended up higher than what Fender traditionally has it set at.

At about 18 static dissipation watts per tube, the sound really opened up. The player can no be very expressive in their playing. Using a lite touch sounds nice and clean while a more aggressive touch makes the amp break up just wonderfully. Find out what your output tubes can handle in wattage. The 5881’s max out at 24.

New Cap

1ohm resistors

. Record . Mix . Master . Music .

1959 Tweed Bassman – Part V

Part 5, Assembly of chassis and speakers into cabinet and final listen:

If you use the MojoTone kit w/cab you will need to have them drill the mounting holes in the 4-10 cabinet to install the chassis. Minor additional charge. Install the 4) 10” Jensen speakers so that the speaker terminals are towards the center of the cab. This will help in wiring and servicing. When installing the chassis turn the cabinet on its side for easier line up of the chassis mounting holes.

There is a time element for the speakers to break-in and loosen up a bit. About 40 hrs. But still, this 4-10 cabinet sounds GREAT! Guitar or bass, this is tone HEAVEN!

If you have found this blog fun and interesting let me know. I had a lot of fun doing it. If you know any guitarists looking for an amp like this I am open to building one out for them.

Great Mix Recording
Great Mix Recording
Great Mix Recording
Great Mix Recording

The previous posts have been opinions from Jacques Sewrey re: the building of a ’59 Fender Bassman clone kit.

Coming up in future blogs will be the modding of and minor circuit changes of the aforementioned Bassman. This will improve the tone options and make biasing for the power tubes easier.

. Record . Mix . Master . Music .
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