Secret manufacturer?
Yes😉😉 (just did not want to sound like a sale's rep.)
They are called Brownsburg Electronics and they manufacture all kind of transformers and inductors. All of there products are custom made.
I've a question regarding the possible devices used in this circuit.
What happens if JFETs with lower transconductance are used than the specified ones? Given that we're not having gain in this configuration, does it change anything but the output impedance of the buffer? Which is in the default configuration mostly dominated by the output resistor, if I'm understanding things right.
I've got proper 2sk170s available, fairly well-matched, just waiting for the caps to arrive to build one of those 🙂 I'm just curious.
What happens if JFETs with lower transconductance are used than the specified ones? Given that we're not having gain in this configuration, does it change anything but the output impedance of the buffer? Which is in the default configuration mostly dominated by the output resistor, if I'm understanding things right.
I've got proper 2sk170s available, fairly well-matched, just waiting for the caps to arrive to build one of those 🙂 I'm just curious.
both the jFETs in the B1 should be sk170. That's a Pass design.I've a question regarding the possible devices used in this circuit.
What happens if JFETs with lower transconductance are used than the specified ones? Given that we're not having gain in this configuration, does it change anything but the output impedance of the buffer? Which is in the default configuration mostly dominated by the output resistor, if I'm understanding things right.
I've got proper 2sk170s available, fairly well-matched, just waiting for the caps to arrive to build one of those 🙂 I'm just curious.
I've got the signal path wired up with matched 2sk170s.
Oddly enough, this still doesn't answer my question 🙂
Oddly enough, this still doesn't answer my question 🙂
I have the B1 board all populated and soldered. Now I need a power supply.
Many thanks
Lucas
I like batteries as it sounds much better to me, but a wall wart also sounds good and is very convenient. Once I stick it in a final chassis I will most likely use 3x high current 6V SLA batteries for a long lasting supply. A couple of 9V last quite a long time too, at least it is exceedingly cheap to try.
Member
Joined 2002
I like batteries as it sounds much better to me, but a wall wart also sounds good and is very convenient. Once I stick it in a final chassis I will most likely use 3x high current 6V SLA batteries for a long lasting supply. A couple of 9V last quite a long time too, at least it is exceedingly cheap to try.
diy is all about cheap, and preferred ideas 🙂 will you have the batteries in the case or external ?
What happens if JFETs with lower transconductance are used than the specified ones? Given that we're not having gain in this configuration, does it change anything but the output impedance of the buffer?
It will work fine, perhaps not the pinnacle of perfection that
you get with the 2SK170's, but very acceptable, as long as
you can get a few mA of bias.
😎
Thank you for the answer Mr. Pass.
I'm looking forward to getting my capacitors and finishing the circuit
I'm looking forward to getting my capacitors and finishing the circuit

diy is all about cheap, and preferred ideas 🙂 will you have the batteries in the case or external ?
most likely external, but the batteries really aren't all that big. I have a lot of Neutrik PowerCon stuff I haven't been able to use yet.
For those of you that haven't tried it, a pair of 9v batteries sounds great.
Member
Joined 2006
How about using matched pairs of 2sk79 VFETs, anything I should be aware of? Would increasing the supply voltage enhance any performance? 

most likely external, but the batteries really aren't all that big. I have a lot of Neutrik PowerCon stuff I haven't been able to use yet.
For those of you that haven't tried it, a pair of 9v batteries sounds great.
How long will the battery last?
Member
Joined 2002
no activity on this projects 🙂
So, what is everyone using for volume pots ? Is the Alps Black Beauty still available ?
What are people using ?
So, what is everyone using for volume pots ? Is the Alps Black Beauty still available ?
What are people using ?
How long will the battery last?
Non-stop, generic alkalines @ 72-96 hours. YMMV 🙂
no activity on this projects 🙂
So, what is everyone using for volume pots ? Is the Alps Black Beauty still available ?
What are people using ?
I will be using this pot: ALPS 4 GANGS 20K AUDIO AMP STEREO VOLUME CONTROL POT! - eBay (item 380151632599 end time Dec-20-09 08:50:23 PST)
As I am building mine as a balanced unit, as far as the "Black Beauty" I still see some on e-bay at times.
Regards

Eric
Member
Joined 2002
I will be using this pot: ALPS 4 GANGS 20K AUDIO AMP STEREO VOLUME CONTROL POT! - eBay (item 380151632599 end time Dec-20-09 08:50:23 PST)
As I am building mine as a balanced unit, as far as the "Black Beauty" I still see some on e-bay at times.
Regards,
Eric
Thanks i saw that on there, id like to buy a VERY GOOD one, i don't want to cheap out on the pot and cap's as this buffer will be one of the key pieces of equipment.
Thanks i saw that on there, id like to buy a VERY GOOD one, i don't want to cheap out on the pot and cap's as this buffer will be one of the key pieces of equipment.
There is always Penny and Gilles, however you will have to spend around 300$ for a stereo pot...
Member
Joined 2002
There is always Penny and Gilles, however you will have to spend around 300$ for a stereo pot...
Yeah, well im not that rich yet 🙂 I fell in love with the Alps Black Beauty a few years ago, but can't find any 🙁
What value are people using 20 k?
Yeah, well im not that rich yet 🙂 I fell in love with the Alps Black Beauty a few years ago, but can't find any 🙁
What value are people using 20 k?
Yes, it was the only value I could put my hands on at a reasonable price...
Member
Joined 2002
Yes, it was the only value I could put my hands on at a reasonable price...
I like the pot, i like the smooth volume control feel, maybe a slight light click but im not a fan of some of those dacts out there that kinda need muscle man to turn them.
The black beauty long time ago that i played with was exactly what i wanted.
J'
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