The smallest resistors you will find are the Mills Audio Resistors.
It is also a good idea to keep the resistors of the PCB with spacer so they can cool down and also not warm up the PCBs.
You can do this with ceramic or metal spacers.
It is also a good idea to keep the resistors of the PCB with spacer so they can cool down and also not warm up the PCBs.
You can do this with ceramic or metal spacers.
22uf cap
I'm curious about the voltage rating necessary for the 22uf cap on the main board (this thread or Kari's thread). BTW, I did receive my boards (some time ago). The "BOM" did not give the rating for this cap.
Thanks,
SteveA
I'm curious about the voltage rating necessary for the 22uf cap on the main board (this thread or Kari's thread). BTW, I did receive my boards (some time ago). The "BOM" did not give the rating for this cap.
Thanks,
SteveA
25V would work for the PS I will make, but I will probably use 50V as it will fit fine.
You would use a capacitor to suite your negative rail voltage.
Cheers!
Russ
You would use a capacitor to suite your negative rail voltage.
Cheers!
Russ
Gain setting
I may try to lower the gain of this circuit. My current linestage is a simple buffer and it gives a real good range to control volume. The speakers make up for the unity gain.
Which resistors set the circuit gain? Will this screw up the results?
I look forward to building this circuit. It seems so slick.
George
I may try to lower the gain of this circuit. My current linestage is a simple buffer and it gives a real good range to control volume. The speakers make up for the unity gain.
Which resistors set the circuit gain? Will this screw up the results?
I look forward to building this circuit. It seems so slick.
George
Hi George. Try this link, Thomas Chao has a nice page with lots of info. Look under audio, and you will find lots of Pass related stuff🙂 For this particular question, look under BosoZ modification.
There is links to Henriks original X-BosoZ and so on.
http://www.penguinlovers.net/index.php
Steen.
There is links to Henriks original X-BosoZ and so on.
http://www.penguinlovers.net/index.php
Steen.
Thanks Steen
Looks like the 10K and 39K resistors do it. I suspected this as such, but hoped to verify.
One more silly question. Do the value of the pots change the gain also? Seems they add to the value of the 10K resistors as seen by the rest of the circuit.
George
Looks like the 10K and 39K resistors do it. I suspected this as such, but hoped to verify.
One more silly question. Do the value of the pots change the gain also? Seems they add to the value of the 10K resistors as seen by the rest of the circuit.
George
Panelhead,
Sorry being late to answer your questions. My wife is going through troubling medical problems at the moment so my spare time is at a minimum these days.
You are correct about the the resistors used to change the gain of the circuit.
As to the pots, their effect on the gain largely depends on the configuration of how they are incorporated into the circuit. In my case, I didn't put pots on the inputs, and the output pots have no effect. Generally, the lower the impedance of the input pots, the less effect they will have on the circuit gain.
Cheers, Terry
Sorry being late to answer your questions. My wife is going through troubling medical problems at the moment so my spare time is at a minimum these days.
You are correct about the the resistors used to change the gain of the circuit.
As to the pots, their effect on the gain largely depends on the configuration of how they are incorporated into the circuit. In my case, I didn't put pots on the inputs, and the output pots have no effect. Generally, the lower the impedance of the input pots, the less effect they will have on the circuit gain.
Cheers, Terry
I made a proto of this design. Etched a couple of the Twisted BosoZ boards and build it😉 I dont like to admit this, but it sounds a bit better than BosoZ with singleended input/singleended output 🙂 With singleended in/balanced out, it sounds a good bit better😎 The sound is overall more tight. For those interested I matched two sets of IRF610's (2x5 pcs) to 0,01V Vgs. I am not sure its necessary to match all the fets, but I just had those two sets from 18 fets straight from the tube. Otherwise I just used fairly cheap parts for the rest of the circuit. As good as this preamp sounds, I will surely build another with better parts😎 The preamp is very quiet, there is no noise and the Mossfet hiss is very faint indeed. I have to turn the volume all the way up to hear it, even then it is at low levels. At this time its running from a very basic BosoZ supply, set up for +60/-20 volts. With a better dual mono supply, it will do even better. So I guess the circuit is working (no surprise) and the boardlayout is correct😎 I hope to finish the Twisted's supply boards next week, just to see if it works as good as the preamp itself😎 Here is a pic of the proto boards🙂 Hopefully the set of boards will be flawless. Its a bit sad with corrections added later on. Dont you think?
Steen😎
Steen😎
Attachments
If you only have SE input and no poweramp with balanced input, the advantage wouldnt be so great. Still I think this circuit sounds better with SE all the way🙂 Its just that bit better than the BosoZ, so I think its worthwhile to build it.
Steen🙂
steenoe said:
I´m asking that because I have a BOZ preamp in my system and I wonder if would be any advantage upgrading with SE Twisted or perhaps with the NS10. Your advise is very appreciated.
JC 🙂 🙂 🙂
Thats a tough one, JC😀 I would say it depends a bit on your poweramp. 1)If you have a poweramp with SE input that demands a powerfull input, like the Zen's, just keep your BoZ. I have a BoZ myself, and it is very musical🙂 The BosoZ is a bit better sounding, but if you use only the half"outputswing" with the -side connected to ground its not as dynamic as the BoZ!
2) If you have a poweramp with normal sensitivity and only SE input, my guess is that the X-CCS-BosoZ sounds that tad better
🙂 Best way to find out is to build them all😀 The NS10, great sounding as it is, is not the best match for a Zenamp. It is a great match for "normal" poweramp. Hope this helps! But as I said, its a difficult question. I took the long road, and built them all🙂 I think the twisted BosoZ will end up in my system, though.
Steen😎
Steen thanks so much for building the prototype. You did excellent work, and got it done so fast! 🙂
I really appreciate the validation of the layout and the little tweaks you made me aware of. 😉
The "Steenoe Caps" are there to stay in honor of your contribution to the design. 🙂
So now I feel very condifent in the Pre and I will be ordering the PCBs post haste.
Cheers!
Russ
I really appreciate the validation of the layout and the little tweaks you made me aware of. 😉
The "Steenoe Caps" are there to stay in honor of your contribution to the design. 🙂
So now I feel very condifent in the Pre and I will be ordering the PCBs post haste.
Cheers!
Russ
steenoe said:
Hey Steen, as we have been accustomed, coming from you, just beautifully twisted.😎
Excellent work🙂 🙂 🙂
Thanks a lot Russ, I just love this stuff you know😀 You made a great preamp😉
Tony, now you know why I didnt finish the F2 yet😀 I will in short time though, I excpect to receive more sturdy source resistors tomorrow🙂 The work wasnt that excellent after all, I just plugged the thing in and sweet music flowed😉 😉 😉 Well more or less at least🙂 🙂
Steen😎