Ah, mighty ZM, mo‘ details, thank you.
A 16-fold output resistance should be taken special care of, I guess?
Caution: the link above is not correct. I use this one:
[url]https://www.don-audio.com/CineMag-CMOQ-4HPC-Audio-UEbertrager-HighNickel
Better resolution, recommended part...
A 16-fold output resistance should be taken special care of, I guess?
Caution: the link above is not correct. I use this one:
[url]https://www.don-audio.com/CineMag-CMOQ-4HPC-Audio-UEbertrager-HighNickel
Better resolution, recommended part...
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And if voltage gain is higher than clean rail voltage? Does the autoformer magically cure that issue or does the rail voltage still set the upper limit for swing? Consider the latter correct, ey Mighty?
[emoji4]
It‘s perfectly aligned with my right ear, but on the left side.
Eversince I upgraded wiring and input capacitors, they ... well...
[emoji1787]
No, sorry, not much wrong with it (except a little tinnitus), it’s just that I liked this as online-name for an audio-related forum...
It‘s perfectly aligned with my right ear, but on the left side.
Eversince I upgraded wiring and input capacitors, they ... well...
[emoji1787]
No, sorry, not much wrong with it (except a little tinnitus), it’s just that I liked this as online-name for an audio-related forum...
ah, and of course, the pics...
wiring still a rat's nest, and the layout, well, is working. Could have been much much nicer...
My first chassis-work, or second preamp after dcb1, and 4th build, 5th when counting bugle2.
the second, empty knob will be the output-selector, HP—0dB—16dB
Headphone-connector still missing...
wiring still a rat's nest, and the layout, well, is working. Could have been much much nicer...
My first chassis-work, or second preamp after dcb1, and 4th build, 5th when counting bugle2.
the second, empty knob will be the output-selector, HP—0dB—16dB
Headphone-connector still missing...
Attachments
I had Jensen's on my F6 not being used. So I carefully extracted those from the pcb's to try this autoformer thing I kept seeing here for some extra gain. With the BA2018 and the F4, I needed just a little more gain, but with my shiny new VFET amp I do not need that extra 6db. So I quickly found out to just jumper past the autoformer with that pairing. Why? I just like experimenting I guess. Wayne's preamp has a nice low output impedance, and my other amps are easy to drive. Why not? And signal iron is "cool".😎
please take care of my tender age, so why 2 (or more) questions at once ?
1. do you know Rout of Line stage in case?
2. what is Rin of F4?
3. compute. compare.damn! it works!
4.
1. do you know Vpp swing of Line stage in case, fed with standard 2Vrms?
2. what is max Vpp swing of F4?
3. compute. compare.damn! it works!
4.
1. do you know Rout of Line stage in case?
2. what is Rin of F4?
3. compute. compare.damn! it works!
4.
1. do you know Vpp swing of Line stage in case, fed with standard 2Vrms?
2. what is max Vpp swing of F4?
3. compute. compare.damn! it works!
4.
Ah, mzm, you have to consider MY tender age, too... I‘m so old I already forgot I asked a question, so there‘s two of them [emoji1787]
(Of course I don’t know, but I guess we‘re that much apart, agewise... wisdomwise, different thing)
(Of course I don’t know, but I guess we‘re that much apart, agewise... wisdomwise, different thing)
so, me being too old to know two {1.} of above, if you know, write here, so we shall compute all day long together
🙂
(I know both of {2.} )
🙂
(I know both of {2.} )
please take care of my tender age, so why 2 (or more) questions at once ?
1. do you know Rout of Line stage in case?
2. what is Rin of F4?
3. compute. compare.damn! it works!
4.
1. do you know Vpp swing of Line stage in case, fed with standard 2Vrms?
2. what is max Vpp swing of F4?
3. compute. compare.damn! it works!
4.
Dennis tries to teach me, but I am a slow learner.
I feed it 2,3Vrms, about 3Vpp. Standard gain about 4x, gives around 12v swing. And the F4 likes a swing of about 20 to max out, according to my teacher. But my preamp rails are max 20Vrms, and if they aren’t clean to more than 17v, I can’t reach full swing on the F4 regardless of gain. Or is that wrong?
You know I can’t compute, Mighty. Only under strict supervision.
But then, if I go for 97 db/sens Zu speakers, WLS with a little bit increased gain and F4 might be a sound match, not needing full output. Maybe...
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This is the realms where I usually royally fail.
WLS Rout ≈ „fraction of an ohm“ (Wayne said that)
F4 Rin ≈ 47K (Nelson/Papa said that)
But, I unfortunately have to leave, gotta prepare dinner and spend time with family...
WLS Rout ≈ „fraction of an ohm“ (Wayne said that)
F4 Rin ≈ 47K (Nelson/Papa said that)
But, I unfortunately have to leave, gotta prepare dinner and spend time with family...
well, nothing wrong with the kiss, boy ........ 🙂
see, post #11, but here too:
https://www.diyaudio.com/forums/att...aynes-ba-2018-linestage-ba2018-r1_wayne_1-pdf
gain is (1+R16/R17)= 3.7V/V=11.36db
Rout is, indeed, fraction of an Ohm
so, fraction of an Ohm multiplied with 4 or 16, still nothing to worry about, considering 47K Rin of F4
swing ........
say you're getting from your source max input of 2Vrms
*2 , that is 4Vpeak
*1.41, that is 5.65Vpp
gain of stage is 3.7, so 5V65*3.7=20.93Vpp , still well below sum of rails ( and they're bloody DC, so you can't call them Vrms, as you did)
F4 is having rails of 24V nominally , say that you can count on proper 40Vpp output swing ( taking losses and real life rails always lower than 24Vdc)
you have coming from preamp 20.93Vpp, so you practically need xformer gain of 2V/V which is 6db, to saturate F4
practically - autoformer connected for gain of 2 (6db) is going to work
if your main source is wimpy in swing ( less than 2Vrms), connect autoformer for 4times gain (12db)
simple as that
see, post #11, but here too:
https://www.diyaudio.com/forums/att...aynes-ba-2018-linestage-ba2018-r1_wayne_1-pdf
gain is (1+R16/R17)= 3.7V/V=11.36db
Rout is, indeed, fraction of an Ohm
so, fraction of an Ohm multiplied with 4 or 16, still nothing to worry about, considering 47K Rin of F4
swing ........
say you're getting from your source max input of 2Vrms
*2 , that is 4Vpeak
*1.41, that is 5.65Vpp
gain of stage is 3.7, so 5V65*3.7=20.93Vpp , still well below sum of rails ( and they're bloody DC, so you can't call them Vrms, as you did)
F4 is having rails of 24V nominally , say that you can count on proper 40Vpp output swing ( taking losses and real life rails always lower than 24Vdc)
you have coming from preamp 20.93Vpp, so you practically need xformer gain of 2V/V which is 6db, to saturate F4
practically - autoformer connected for gain of 2 (6db) is going to work
if your main source is wimpy in swing ( less than 2Vrms), connect autoformer for 4times gain (12db)
simple as that
Good one, Mighty. So for my part we are talking:
2V3 from source. 2V3x2x1,41=6v5
Sum of rails are 40. Following Dennis’ advice, maybe 17 of these are clean. Sum is then 34.
34/6v5=5V25 needed gain to reach possible max of preamp with those rails. Still 6V below saturating the F4. I am thinking that gain is reachable through tweaking R16/17.
If we say sum of rails of 40 is all clean, gain neded to reach that swing is 6v16.
And so, ideally, I guess rails of preamp should be 24v iot to feed the F4 to full about without a hitch.
Is that about correct?
In my hypothetic F4, rails will be normal FW style, Choky recipe pimped a bit up with more capacitance.
Anyways, if I do build the F4, I will have a BA-3 FE in surplus to make a preamp out of =)
Regards,
Andy
2V3 from source. 2V3x2x1,41=6v5
Sum of rails are 40. Following Dennis’ advice, maybe 17 of these are clean. Sum is then 34.
34/6v5=5V25 needed gain to reach possible max of preamp with those rails. Still 6V below saturating the F4. I am thinking that gain is reachable through tweaking R16/17.
If we say sum of rails of 40 is all clean, gain neded to reach that swing is 6v16.
And so, ideally, I guess rails of preamp should be 24v iot to feed the F4 to full about without a hitch.
Is that about correct?
In my hypothetic F4, rails will be normal FW style, Choky recipe pimped a bit up with more capacitance.
Anyways, if I do build the F4, I will have a BA-3 FE in surplus to make a preamp out of =)
Regards,
Andy
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Andy, just for my better understanding, those final, unclean 3V ... does that mean that you're going to stop your attenuator at 17/20 (the rest of the attenuation been prone to unclean amplification)? Or does it mean that you are using 17/20 of the PSU to feed the stage?
And, your Fynes have some excellent 91dB sensitivity, that's almost twice as loud as mine… so you should be able to get in trouble with your neighbors already? (Maxing out f4 would mean to invoke a renovation-team I guess…)
And, your Fynes have some excellent 91dB sensitivity, that's almost twice as loud as mine… so you should be able to get in trouble with your neighbors already? (Maxing out f4 would mean to invoke a renovation-team I guess…)
ideally, to avoid clogging in preamp, same need to have at least slightly higher rails than F4
so, 28V rails for preamp, then just crank gain, with ratio of R16/R17
so, 28V rails for preamp, then just crank gain, with ratio of R16/R17
