steenoe said:Okay guy's, we have a working preamp
Steen
Nice to hear that Steen
What sort of arrangement do you have as output cap?
If you did the lytic with bypass (or sans) leave a positive voltage over the positive terminal of the cap, assuming you have the + lead to the side of the circuit. This will bias the cap for a better sound. A couple of volts will be nice if this does not mean you are clipping the output signal before you reach a 5 volt peak to peak.
Quick and nice work as usual
lumanauw said:Hi, Steenoe,
It works?
I don't know if I'm hearing wrong, but when I don't use the DC offset adjustment R (or VR) it sounds better for me. I can leave the DC offset (I got 500mV) because the output is cap coupled.
That’s a good idea when you finish playing around with the pot
It does indeed
Lumanauw, thanks for posting your values in the other thread This is just the start, I am sure I will play around a lot with this preamp.Just a cheap NP cap, for starters
Doesnt even sound too bad I have a couple of those big MKP's waiting to be soldered in.BTW did you get my mail yesterday, Tony?
Steen
OFF TOPIC
I'm also into glass!!! love preamps and also made a couple of 150W monoblock including all trafos.
My pet pre is a 417A waiting to be transformed into an Euridice type. But I'll change that to a 12B4 which I'm ordering now, after reading Mark G's thread
Have also seen yours at your site, very nice Choky
choky said:
yo my man-who is da sand specialist here?
not me-fer sure!
I'm also into glass!!! love preamps and also made a couple of 150W monoblock including all trafos.
My pet pre is a 417A waiting to be transformed into an Euridice type. But I'll change that to a 12B4 which I'm ordering now, after reading Mark G's thread
Have also seen yours at your site, very nice Choky
apassgear said:
Yes, tweaks
How about starting right now?
Add a film cap across the ref zeners.
I guess it can also be done with FET.
tweaks:mebbe to split each of 47ohm resistors in two resistors and try to feed that point via small cap from output (25 and -25,respectively)
that looks like some noise cancelation ,or I'm wrong here? (seems that I'll install some sim software ,just for quickies........ )
film cap across zeners -that looks like nono in this case.......
fets-why ? are they faster than good ole BD in resistor role
choky said:
film cap across zeners -that looks like nono in this case.......
fets-why ? are they faster than good ole BD in resistor role
Film cap to reduce zener noise and get a somewhat more stable voltage reference.
On this forum is more politically right to use FET
More tube like? Cant say. Anyway, I guess I couldn't hear the difference, so each can put what they have at hand.
apassgear said:
Film cap to reduce zener noise and get a somewhat more stable voltage reference.
On this forum is more politically right to use FET
More tube like? Cant say. Anyway, I guess I couldn't hear the difference, so each can put what they have at hand.
sometimes cap across voltage reference in shunt type regs can influence speed (or voltage-current ratio in time domain) ,not in a good way; I say -sometimes.....not necessary in this case. just one thing to try and listen ,too....
regarding shunt eater type- who cares
.......hehe-look: 17 pages allready........
Agreed
But I remember NP himself once used a Bipolar transistor in a supply (BoZ) I second that question, it would be nice with some input on that issue. I am using MPSA18 for Q1 and Q2 at the moment. Just ordered some transistor-sockets, so I can play with different transistors without resoldering
Since there weren't any suggestions for tweaks on the preamp board, I will make two new boards up with better parts, and socket for at least Q1 Steen
Sure thing
This little linestage is sounding pretty good so far! Its not too good, connected to my ZenV4, but with my other amps, its just great! I had a good listen connected to my Zapsolute! Great excperince! The Zap is here: http://www.lcaudio.com/index.php?page=29 I dont mean to do any advertising on that one, but nonetheless It sounds incredibly good This little linestage is good with average components! I am sure it will be great with better components!I am about to do a better built
Will keep you posted Steen
I am still working on it
BTW I have a little trouble getting it to play right But I am sure ILA will guide me through the prob's Greetings from Denmark
Steen
Edit. The link didnt work, try this one: http://www.lcaudio.com/index.php?curr=2
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