Blog Pages

6/15/17

12AX7 Vacuum Tube Breadboard Adapters On Ebay

BB-NOVAL TUBE ADAPTERS ON EBAY

These are now available on Ebay at this link: BB-NOVAL Breadboard Adapters


They also work with other tubes such as 12AU7, 12AT7 and the EF86 Pentode.  You can learn how to design your own 12AU7 gain stage by reading my white paper 12AU7 Gain Stage Example.

Thanks for reading,
Trenton

12AX7 Vacuum Tube Breadboard Adapter On Ebay

BB-X7 VACUUM TUBE ADAPTERS ON EBAY

These are now back on Ebay at this link: BBX7 Breadboard Adapter.


Find out how to design your own 12AX7 Gain Stage by reading my white paper "12AX7 GAIN STAGE EXAMPLE on my website at trentonblizzard.com .


If you have any questions you can comment here or contact me via my web page.
Thanks for reading,
Trenton


6/13/17

Orange Dual Discrete OpAmp

Orange - Dual Discrete Audio OpAmp

Orange has a new discrete opamp available for purchase. According to Orange, "it's among the most musical sounding dual discrete op-amp out there."


https://orangeamps.com/shop/components/op-amp/#top
SPECS:
Unity gain stable
Rail Voltage: +/- 18 volts max
Current Draw: 18mA
Slew Rate (min): 38V/uS
Open Loop Bandwidth: 48kHz
Open Loop Gain: 112db

PACKAGE SIZE:
Common DIP-8 pinout.
PCB height is 22mm. So, you will need to check for any clearance issues inside your gear.

APPLICATIONS:
According to the Orange web page, it uses low noise JFETS in the front end. It can be used in any CD player, DAC, or preamplifier that currently runs DIP 8 based IC dual op-amp types.

Since JFETS have inherently low current noise, this opamp could be a good choice for the front end of a DI as well. However, 18mA might kill your battery fairly quickly.

It is reported that it can replace the following dual opamps: (clearance accounted for)
    OPA2604
    OPA2134
    TL072
    NE5532
    LM4562
    OP275
    OP285

COST:
£42.00 | $55
Available from the online Orange store.

Thanks for reading,
Trenton

6/7/17

How To Build A 12AX7 Gain Stage Part 4 (Measurements)

Part 4 of my video series on How To Build A 12AX7 Gain Stage. This video covers DC measurements, AC gain measurements, and frequency response measurements. SPICE simulation is then compared to the real-world tube circuit.



Thanks for watching,
Trenton

5/5/17

DIY ACOUSTIC ABSORBERS

 5-27-2017 ABSORBERS ON WALL

Two out of the four absorber kits are finally mounted on the wall using the supplied Z-Clips. TIP: You can gain a little more room "absorption" by spreading out your absorbers a bit. This is due to "diffraction", or "bending" of the sound wave. When a sound wave bends around an object, some of the energy is reduced giving an apparent increase in "absorption"

Z-CLIP HARDWARE

Since these absorbers are fairly large I needed to make sure to anchor them well. Here you see the supplied Z-Clips mounted to the wall spaced 12" apart. Note: they are not perfectly mounted. In fact, not a single piece of my hardware is exact.

Remember, it's more important to get it up and on the wall than it is to worry about having it perfectly mounted. Just make sure it's NOT going to fall off the wall.




Zinc Self Drilling Drywall Anchors

For the right absorber I got lucky and hit wall studs so I just needed long drywall screws for both Z-clips. For the absorber on the left I used zinc self drilling drywall anchors (shown below). You use a drill to drive them right into the drywall. Then you use small screws to mount your Z-Clips. 


5-5-17
I recently ordered (4) DIY422 Panel Kits from Acoustimac in Florida.  These absorbers measure 48" x 24" x 2".  Although I usually order my panels with Owens Corning 703, this time I decided to try something new and ordered the Roxul Rockboard core material.  
http://www.acoustimac.com/

DIY ABSORBERS?
When I saw the images online I thought I would be building everything except the frame.  However, you can see the image below of how they came right out of the shipping box.  The only thing left to really "DIY" is the fabric covering. Everything else was pre-assembled.


ROXUL ROCKBOARD CORE
According to Acoustimac, Roxul Rockboard has better absorption properties than Owens Corning 703. I'm not sure I'll be able to detect the difference in my tiny room.


CLOUD ABSORBER
I will be hanging two of these panels from my ceiling as a cloud absorber. The other two will go on the wall.  I will be installing hardware in each corner of the frame to allow me to attached cables from the ceiling. Access to the inside of the panel is the main reason I ordered kits.


ABSORBER COST?
I feel Acoustimacs prices are very fair. Each of these 48" x 24" x 2" panels were only $42.00 each including fabric.  I will post more as I finish them.

UPDATE 5-13-2017:
Added simple eye bolts to each corner for hanging.



UPDATE 5-20-2017:
I'm not sure if it helps but I rounded off the frame edges and corners using a belt sander. Image below of an absorber that is going on the wall. (Not the ceiling)


 As the sun goes down I put the fabric on. Make sure to use a good staple gun. I used an Arrow T50 with T50 1/4" staples #504. (Image of a wall mounted absorber)


It's now dark outside as I mount the "Z Clips" that are supplied with the kit. (Wall mounting only) The panels are 24" wide so I mount the clips 6" in from each side and 6" down from the top.


More coming soon: Finishing up the ceiling absorbers and installation.

Thanks for reading,
Trenton

5/1/17

How To Design A 12AX7 Gain Stage - Part 3

Part 3 of my "How To Build A 12AX7 Gain Stage". This video demonstrates how to build a 12AX7 common cathode gain stage on an electronics breadboard using vacuum tube breadboard adapters.


Thanks for watching,
Trenton

4/14/17

How To Design A 12AX7 Gain Stage - Part 2

Part 2 in this video series where I show you how to simulate and build a 12AX7 vacuum tube gain stage.



Thanks for watching,
Trenton