arnoldc,
I lied... I am not totally deaf... yet. My only point is that newbies (especially an engineering student) should learn from what is known, and NOT that which is merely suggested.
I wish to inspire those with working hands to realize the joys of their labor... I don't care to distract or impede those who lack money... I have heard the most VERY expensive systems... that sounded like like s**t.
I lied... I am not totally deaf... yet. My only point is that newbies (especially an engineering student) should learn from what is known, and NOT that which is merely suggested.
I wish to inspire those with working hands to realize the joys of their labor... I don't care to distract or impede those who lack money... I have heard the most VERY expensive systems... that sounded like like s**t.
Commited, bottlehead needs to make a little money, don't they? My cheap Foreplay pic is attached.
Ray_Moth, what is silly in allowing you a choice to change phono stages? And what about aesthetics? It's about choice.
poobah, lie was taken with a bucket of salt I agree with you on the suggestion point, which we can also take with a bucket of salt. until you build it (or bought it) then its the only time to know if it's actually **** or not.
ps.
nobody would like to take a stab on whether the Foreplay is well-engineered or not?
My cheap Foreplay pic is attached.Ray_Moth, what is silly in allowing you a choice to change phono stages? And what about aesthetics? It's about choice.
poobah, lie was taken with a bucket of salt
I agree with you on the suggestion point, which we can also take with a bucket of salt. until you build it (or bought it) then its the only time to know if it's actually **** or not.ps.
nobody would like to take a stab on whether the Foreplay is well-engineered or not?
Attachments
from the pov of a diy'er, there will always be room for improvement, that is why you see some mods on the web on how to improve it, personal tastes are at work here.
looking at the foreplay schematics, i guestimate it to have a voltage gain of about 2 or 6db, being a common cathode gain input direct coupled to cathode follower.
arnold, are you the designer of the tono violin? are you at liberty to divulge circuit here? is it an srpp or a cathode follower, since 1 tube per channel was used, it must be one of those two, or am i missing something.
Tony, nope, I did not.
I just read books and diyaudio and make the circuits, he he.
if i remember right, someone was educating me before that the Foreplay implementation is running on a non-linear region, but to me it still sounds good!
when I tried to make my own cathode followe pre using the 407 tube, i was forced to look at the curves, and try to operate it on a linear region. but funny thing is, while it sounded good, operating it in the non linear region, sounded better.
so, how's that? wrongly engineered approach? but sounds good?
what is the definition of a well-engineered circuit?
I just read books and diyaudio and make the circuits, he he.
if i remember right, someone was educating me before that the Foreplay implementation is running on a non-linear region, but to me it still sounds good!
when I tried to make my own cathode followe pre using the 407 tube, i was forced to look at the curves, and try to operate it on a linear region. but funny thing is, while it sounded good, operating it in the non linear region, sounded better.
so, how's that? wrongly engineered approach? but sounds good?
what is the definition of a well-engineered circuit?
I think that Mark's requirement are almost the same as mine, so maybe I'm too adventurous to suggest to take a look at the schematics on my site?
My preamp is made of a phono preamp and a passive line amp (just a pot to vary the volume). You can make it with whatever inputs/outputs you want, and it's very quiet because of regulated DC heaters and B+. Also very simple components and very avabile.
You just have to get a 230/110V isolation tranny (or a 230/230 one if you discard the voltage doubler supply), a 12V @ 2A tranny, 2 ECC83, 1 ECC81/88 and you're done
My preamp is made of a phono preamp and a passive line amp (just a pot to vary the volume). You can make it with whatever inputs/outputs you want, and it's very quiet because of regulated DC heaters and B+. Also very simple components and very avabile.
You just have to get a 230/110V isolation tranny (or a 230/230 one if you discard the voltage doubler supply), a 12V @ 2A tranny, 2 ECC83, 1 ECC81/88 and you're done
arnoldc said:
unfortunately the tube data sheet curves does not always show clearly the operating points we wish to operate on, so maybe this is what you call non-linear region, but actualy it is not.
non-linear region to my mind is that region where tubes are saturated, meaning increasing grid bias does not produce a commensurate increase in plate current, or when the tube is in deep cut-off so that any further negative bias does not produce any more decrease in plate current. i know this hold true for ss but is also true for tubes. for as long as there is a coresponding change in plate current with every change in grid bias, then you are still in linear operation.
so, when i look at the data sheet, i do a lot of extrapolations and interpolations and hope that i am within strinking distance
SY said:
Ahh great. Is the difference between an active and passive amp the addition of gain?
I probably wouldnt want to tear open an LP to put in a pre-amp, but I suppose a pre-amp box right beside it would be a good compromise?
poobah said:arnoldc,
I lied... I am not totally deaf... yet. My only point is that newbies (especially an engineering student) should learn from what is known, and NOT that which is merely suggested.
I wish to inspire those with working hands to realize the joys of their labor... I don't care to distract or impede those who lack money... I have heard the most VERY expensive systems... that sounded like like s**t.
I'm all for using tried and tested previous designs that have given good results - especially to start off.
I have some experience of expensive systems - I've never heard a bad expensive system. I've heard alot of overpriced ones though.
Up till now I've been a fan of Arcam/Naim/Meridian/B&W stuff. I like the "british" sound I suppose.
arnoldc said:Commited, bottlehead needs to make a little money, don't they?
nobody would like to take a stab on whether the Foreplay is well-engineered or not?
Where can I get the schematics for a Bottlehead Foreplay?
A guy I know has offered me a Bottlehead Foreplay to try - apparently it has a problem of uneven gain in each channel thats wearing out valves quickly...
Giaime said:I think that Mark's requirement are almost the same as mine, so maybe I'm too adventurous to suggest to take a look at the schematics on my site?
My preamp is made of a phono preamp and a passive line amp (just a pot to vary the volume). You can make it with whatever inputs/outputs you want, and it's very quiet because of regulated DC heaters and B+. Also very simple components and very avabile.
You just have to get a 230/110V isolation tranny (or a 230/230 one if you discard the voltage doubler supply), a 12V @ 2A tranny, 2 ECC83, 1 ECC81/88 and you're done
Cheers for the link dude - I had a good look. It looks interesting, but tbh I'm not sure how it all fits together. Could you knock me up a quick schematic for a 3 line pre-amp?
How about tape-out - whats the deal there?
It's the power supply thats really causing me a headache, and probably the part I'd be the most afraid of. Can you buy suitable supplied pre-made?
Cheers,
Mark
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