I would say 24V-ish is optimal. And 2x9V is not going to last real long...
I'd suggest 16 AA batteries. I religiously turn it off after I am done playing and listen for about an hour a day. The 16 AA's last a couple of months or so. Usually I replace them when they get down to 20-ish volts.
I've tried NIMH and Alkalines...I prefer the alkalines. Last longer too.
A SLA (lead-acid) setup would be great.
I'd suggest 16 AA batteries. I religiously turn it off after I am done playing and listen for about an hour a day. The 16 AA's last a couple of months or so. Usually I replace them when they get down to 20-ish volts.
I've tried NIMH and Alkalines...I prefer the alkalines. Last longer too.
A SLA (lead-acid) setup would be great.
Too bad I planned small (15cmx15cmx9cm) box for preamp... Ehhhh, scr** this 🙂 I shall construct a power supply!
I don't know what you are planning for a PSU but it's pretty well known that this circuit has pretty poor PSRR...
You might be better with batteries. Just put them in a different box.
You might be better with batteries. Just put them in a different box.
Update: added a B1 to the Boozehound.
Immediate impression is that I'm getting a bit more impact to the kicks and better extension in the treble. I suspected there was a bit of impedance mismatch between my Tubelab SSE's 50k pot and the 3k16 output impedance of the Boozehound by itself. Very pleased with the addition of a buffer.
Immediate impression is that I'm getting a bit more impact to the kicks and better extension in the treble. I suspected there was a bit of impedance mismatch between my Tubelab SSE's 50k pot and the 3k16 output impedance of the Boozehound by itself. Very pleased with the addition of a buffer.
Just a small update (wow it's been two years). In order to match my Boozehound better with a new SET amp that has lower input sensitivity, I wanted to add some gain. Decided to try bypassing the source resistors of the input JFETs as I had read it would give me a few more dBs. Stuck a 470uF cap across the source resistor on both Q1s and it did the trick. More boogie!
If anyone else is using this board with a passive or buffer pre, this is a nice little mod. Feels like I've got a bit more bass too, but that may just be an effect of the extra signal.
If anyone else is using this board with a passive or buffer pre, this is a nice little mod. Feels like I've got a bit more bass too, but that may just be an effect of the extra signal.
I have looked at the PCB layout of the Boozhound, and the datasheet of the 2SK170. Maybe I am missing something, but isn't the 2SK170 drawn the wrong way round on the PCB? The PCB can be viewed at http://cdn.shopify.com/s/files/1/0289/4153/products/IMG_9344_1024x1024.JPG?v=1391500512
The datasheet for the 2SK170 is at http://www.mouser.com/ds/2/408/6909-57550.pdf
The schematic is at https://cdn.shopify.com/s/files/1/0289/4153/files/BoozhoundLaboratoriesJFETMCPrePre.pdf
The LSK170 is supposed to be a direct replacement. The datasheet for that is at http://www.linearsystems.com/assets/media/file/LSK170.pdf
Please, can somebody help me out and tell me if I am reading the datasheet pin out configuration wrong?
The datasheet for the 2SK170 is at http://www.mouser.com/ds/2/408/6909-57550.pdf
The schematic is at https://cdn.shopify.com/s/files/1/0289/4153/files/BoozhoundLaboratoriesJFETMCPrePre.pdf
The LSK170 is supposed to be a direct replacement. The datasheet for that is at http://www.linearsystems.com/assets/media/file/LSK170.pdf
Please, can somebody help me out and tell me if I am reading the datasheet pin out configuration wrong?
The part's data sheet shows the front and the bottom, with the drain on the left. The pcb's part
outline is not very clear, so just insert the jfet to match the lead connections to the right resistors.
I found a better picture of the PCB at http://diyaudioprojects.com/Solid/JFET-MC-Pre-Preamp-Kit/JFET-Moving-Coil-Pre-Preamp-Kit-Parts.jpg that shows the tracks from the drain going to R3, and the source going to C4. That's completely the other way round.
It does look at the 2SK170 layout is wrong on the PCB😱. That then brings up a very intriguing question: why does the circuit still work with the FET the wrong way round? Everyone who bought this kit would have soldered it in according to the silk screen printing on the PCB. I'll be interested to hear from anyone who has built this kit.
It does look at the 2SK170 layout is wrong on the PCB😱. That then brings up a very intriguing question: why does the circuit still work with the FET the wrong way round? Everyone who bought this kit would have soldered it in according to the silk screen printing on the PCB. I'll be interested to hear from anyone who has built this kit.
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Most FETs (unlike bipolar devices) will function if the drain and source are exchanged,
but may work better when connected the "right" way, depending on the particular device.
Hey, sorry I never responded! I must have unsubscribed to this thread at some point. Unfortunately, I didn't snap pics of this mod.
Basically, you just want to connect a cap (470uf in my case) across R3. Positive side of the cap is on the JFET side (negative goes to ground). I did this on top of my board because the standoffs were not tall enough to put it underneath. If this increases gain too much, you might want to increase R12 to 100 ohms or so.
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