If you don't mind my asking, where did you get this adapter or did you make it yourself? I used these boards to make my LS but never came up with a good way to mount them.
Superb and compact work. My congratulation. How did you realised the balance control ? I begin to restore a vintage preamp and it's make no sense to me to replace the volume control with aa expensive step attenuator and left the original balance carbon pot (or replace it with a 5$ one).
Thank you. I enjoy the challenge of getting a lot to fit in a small space. Reminds me of all the military and aerospace junk I drooled all over at electronic surplus stores. Wish they weren't about all gone now.
I felt I didn't need a full balance control, rather just a little bit to account for speaker placement. Using a two pole 12-position switch, I made little circuit boards to hold resistors. When the switch is turned to the right, the right channel does not pass through any resistors, but the left goes through progressively higher resistor values. Opposite deal when the switch is turned to the left. I took a guess and just picked the lowest six values on the main attenuator, but this does not offer all that much of a decrease in volume of the affected channel, so I'll need to choose different values and replace them.
Can anybody here suggest practical values for the six resistors per channel? I'm only looking to lower the volume of one channel at a time by perhaps 20%, and am obviously limited in the number of steps available, so I'll put up with not having super fine steps.
You could look up some attenuator-calculator, like the one from ELMA, but this is for a Ladder-attenuator. There, you have all options you need (dB per step, input impedance) and you will receive valid e96 resistor values!
I started ordering parts for wls and for Pete Millet's 12v psu. In looking at diyadudio store chassis it looks like the galaxy would be a tight fit and the Pesante would be way bigger than needed. I'd like to put both boards in the same chassis. Anyone know if the Galaxy would work? Or, what have you used that you like. I'm a good cabinet maker and thought of making one out of wood....
It very much depends on which size of the galaxy you‘re going to use (store offers 4) and what parts you will be using (transformer, capacitors, heatsinks), as well as what additional things you want to have (source selector, volume-control). There are some very tight builds around, some barely bigger than the 2 boards, while others went really big.
If you’re planning to make a 1U high build (4 cm inner height, you have to carefully select caps and transormer…
I recommend to first make a dummy box out of cardboard (or anything not pesante on the wallet 😉 )
I‘m not sure wether that 12V PSU will be good for the wls, which requires 15V minimum I believe? Is it this one? http://www.pmillett.com/audio_power_supply.html
If you’re planning to make a 1U high build (4 cm inner height, you have to carefully select caps and transormer…
I recommend to first make a dummy box out of cardboard (or anything not pesante on the wallet 😉 )
I‘m not sure wether that 12V PSU will be good for the wls, which requires 15V minimum I believe? Is it this one? http://www.pmillett.com/audio_power_supply.html
getgoin:
I built a two-chassis BA2018 preamp using two Galaxy chassis (see post #5270: https://www.diyaudio.com/community/...y-pass-amplifier.166784/page-264#post-6264974). You are presumably focused on one of the larger Galaxy-series chassis (I suspect the 2U 330x280 model). So long as your design isn't too complex, you should be okay. Of course, the Slim Line series is simply a wider version of the Galaxy boxes.
Regards.
I built a two-chassis BA2018 preamp using two Galaxy chassis (see post #5270: https://www.diyaudio.com/community/...y-pass-amplifier.166784/page-264#post-6264974). You are presumably focused on one of the larger Galaxy-series chassis (I suspect the 2U 330x280 model). So long as your design isn't too complex, you should be okay. Of course, the Slim Line series is simply a wider version of the Galaxy boxes.
Regards.
Just to revisit pages 191-2 regarding the Academy Audio VCX volume control. I had a problem where volume would jump to max. Lenny the owner said it required a flash upgrade, so I sent it back. Turn around was very quick, and I haven't had this problem since. Great business to deal with and the muses remote volume control works great.
I use a volume control from Academy Audio also. Lenny is very helpful and the volume control he sells has an amazing good sounds qualit! Very, very much recommended!
I am also building the WLS preamp boards, and it’s my first “hands-on” experience with smd semiconductors, in particular, j-fets. I was not happy with my soldering job on them and decided to straighten them up. Old eyes and too much heat damaged a couple of the j-fets and I’m now one short. I ordered replacements from Mouser and am now ready to try again. So, my questions are:
1. I assume that since the original j-fets were from the same reel, they may have been from the same manufacturing batch and therefore relatively well matched. Is this a reasonable assumption or naive?
2. Since my replacement j-fets are from a different reel and therefore almost certainly from a different batch, they will likely not be acceptably matched with the original ones I used? Reasonable or naive?
3. Should I remove the seven that are currently in place and install eight new ones from the same reel, or should I just install the one new one?
Thanks in advance for your guidance. I’ll try to do a better job the second time around.
1. I assume that since the original j-fets were from the same reel, they may have been from the same manufacturing batch and therefore relatively well matched. Is this a reasonable assumption or naive?
2. Since my replacement j-fets are from a different reel and therefore almost certainly from a different batch, they will likely not be acceptably matched with the original ones I used? Reasonable or naive?
3. Should I remove the seven that are currently in place and install eight new ones from the same reel, or should I just install the one new one?
Thanks in advance for your guidance. I’ll try to do a better job the second time around.
Don't worry about mis-matched JFET.
It will not affect to sound real good unless you are hunting for infiniticimal DC offset/distortion.
Focus to get SMD JFET correctly, either by using heat blower and solder tin paste or new and sharp soldering iron tip.
Got my parts from the store for WLS. The markings on the high output transistors don't match anything on the schematic or in the BOM. I tried searching on the numbers on the transistors themselves and that didn't return any results.The transistors that came in the kit:
239015 C004B
231031 A004B
Which ones are Q8 and which ones are Q10?
239015 C004B
231031 A004B
Which ones are Q8 and which ones are Q10?
See Figure 6.1 on page 3 of the Toshiba datasheets (attached)
The one marked C004B is Toshiba part number TTC004B. It is an NPN bipolar transistor.
The one marked A004B is Toshiba part number TTA004B. It is a PNP bipolar transistor.
Wayne's circuit schematic will tell you which transistors are NPN type and which transistors are PNP type.
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The one marked C004B is Toshiba part number TTC004B. It is an NPN bipolar transistor.
The one marked A004B is Toshiba part number TTA004B. It is a PNP bipolar transistor.
Wayne's circuit schematic will tell you which transistors are NPN type and which transistors are PNP type.
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Have you looked at the alternate part number column of the sheet that was included in the kit? There is information there.