i wonder if i have something wrong in the dac section, or if one of the chips is bad. I can easily set the voltage without the dac stage, connect it and it drops one wont budge past 5.16.
I have a couple of high idss 170sk's so i can try that the 2sk170s were matched at 7ma idss. first i will pull the dac chips and see. As i said though, its sounds great and nothing is getting hot, so maybe you are right, its just coming up short.
I have a couple of high idss 170sk's so i can try that the 2sk170s were matched at 7ma idss. first i will pull the dac chips and see. As i said though, its sounds great and nothing is getting hot, so maybe you are right, its just coming up short.
Hi! The Salas shunt low is exelent, and the PCb is not wrong, it is easy adjust V-out, now you can adjust to 5.6V.
After R 10 Ohm and Tl 431 lost about 0.3-0.5V.
You can check abut the 2 LED and Trimer
Hi! Admus. about the Salas shunt and the set curent for DAC you can see in the my image!
Attachments
A simple mod with this could be to ditch the 47k resistors and build a simple cascode CSS with led ref (keeping the bias scheme). That would flatten the load line and probably reduce distortion a little (although its only 0.2% anyway! we arent swinging much voltage anyway, so i really am being picky i think. It would increase the gain too, which probably isnt wanted.
About the IV 5687. Andrea has mesure many the value or R Anod, so we are like 47K paralle.
About the Cascode with 2 led gree you can try to it, but i dont like the sound when use led.
you can try remove C by bass, I think you like sound .
About the IV 5687. Andrea has mesure many the value or R Anod, so we are like 47K paralle.
About the Cascode with 2 led gree you can try to it, but i dont like the sound when use led.
you can try remove C by bass, I think you like sound .
I love 6h6pi and 6h30pi, i have been to design cricuit of use parallel 6h6 and 6h30 few year ago. I make many PCB for my friend, they was like them.
The sound is excellent, I love them. the and new pre818 I use 2 tube 6h30 or 6h6 parallel.
In this circuit, you can try do most for IV stage if you like it.
6h30 is better than 6h6.
Attachments
No! i have not This I/V, I say you can mod I/V use 5687 for use 6h6p.
If you like i can gift for you one PCB 5687, and you cand mod it! it is easy!
at some point i am going to try this, or something very similar. A more modern twist on the iv stage.
Thats a very quick sketch up so probably many errors but the basic approach should be readable.
the 6n6p has 800ma heater current so a similar load to the 5687 so the PS could remain as it is.
Rset should be for 30ma, as its a paralellel arrangement. I would try it with just one side of the triode first to be honest.
Thats a very quick sketch up so probably many errors but the basic approach should be readable.
An externally hosted image should be here but it was not working when we last tested it.
the 6n6p has 800ma heater current so a similar load to the 5687 so the PS could remain as it is.
Rset should be for 30ma, as its a paralellel arrangement. I would try it with just one side of the triode first to be honest.
Last edited:
Yes I know it, CCS is very good with some kind of tube, but I really do not like CCS for 6h6 and 6h30 at anod.
The sound of it is skewed, not natural.
I agree with you about using LED instead of the resistance
Last edited:
Salas.
I am testing the shut reg for the +5 dig that wont go above 5.16.
Leds are dropping 3.92v and the trimmer is dropping 0.75v at 161 ohms. combined vref of 4.67
I through trimmer = 0.75/161 = 4.6ama, which seems low for the jfet (originally matched at 7ma idss @10v.
Strnage thing is, the trimmer has more turns left, but it doesnt affect the voltage.
any thoughts from the wizards?
I am testing the shut reg for the +5 dig that wont go above 5.16.
Leds are dropping 3.92v and the trimmer is dropping 0.75v at 161 ohms. combined vref of 4.67
I through trimmer = 0.75/161 = 4.6ama, which seems low for the jfet (originally matched at 7ma idss @10v.
Strnage thing is, the trimmer has more turns left, but it doesnt affect the voltage.
any thoughts from the wizards?
Last edited:
Salas works well, not in it,
probably Board DAC have something wrong place, you can check please!
if you are in doubt about this?
so the voltage you measured at the foot of Cs8414 and 74hc04 is like?
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.