hi cviller, hi Variac, 
I suppose there is another small problem with the frontstage board of BA-1 and BA-2.
In the manual of BA-2 Nelson mentions the possibility to use an Elma Silmic for C203 and advises ".... in which case you want to orient the + polarity pointed to the left, toward the R215."
This only true for BA-2!
For BA-1 you have to change polarity vice versa!
But on the frontstage board the polarity is marked only for the BA-2 case.
BA-1 users might have problems when using electrolytic capacitors!
Am I right?
best regards
and I hope you have the same fine summer weather we have here now
I suppose there is another small problem with the frontstage board of BA-1 and BA-2.
In the manual of BA-2 Nelson mentions the possibility to use an Elma Silmic for C203 and advises ".... in which case you want to orient the + polarity pointed to the left, toward the R215."
This only true for BA-2!
For BA-1 you have to change polarity vice versa!
But on the frontstage board the polarity is marked only for the BA-2 case.
BA-1 users might have problems when using electrolytic capacitors!
Am I right?
best regards
and I hope you have the same fine summer weather we have here now
...... I know it is holiday time,
Nevertheless is there anybody outside there who can help me with my problem what to do with the two biasing branches of BA.-1 when I omit the coupling cap ( see posting 158 ).
Should I keep the negative branch and the positive branch is done by the front stage?
Nevertheless is there anybody outside there who can help me with my problem what to do with the two biasing branches of BA.-1 when I omit the coupling cap ( see posting 158 ).
Should I keep the negative branch and the positive branch is done by the front stage?
Oh thanks Zen Mod,
The best is I give you the BA-1 link. Nelson mentions on page 5 : Strictly speaking you do not have to use this capacitor, but it does make adjustment and long term DC stability very easy to achieve.
I want to omit the coupling cap do you understand his words right I have to keep the negative branch and the positive part is taken over by the front stage?
http://www.diyaudio.com/forums/diya...g-amplifier-ba-1-a.html?garpg=5#content_start
The best is I give you the BA-1 link. Nelson mentions on page 5 : Strictly speaking you do not have to use this capacitor, but it does make adjustment and long term DC stability very easy to achieve.
I want to omit the coupling cap do you understand his words right I have to keep the negative branch and the positive part is taken over by the front stage?
http://www.diyaudio.com/forums/diya...g-amplifier-ba-1-a.html?garpg=5#content_start
generg - please put here exact output stage you want to use ;
pictures are small enough , so don't hesitate to post them ;
my problem is that I'm often mixed in few threads , so it's sometimes mess in my head while trying to keep up with several different heads ......
..... You must have at least 15 heads!
OK - I'm digging it , but just half
you want BA1 output stage , connected to BA1 input stage , but DC coupled ?
or what ?
just let me know , and I'll do the pictures
edit :
I digg it 100%
pics later
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whoa ! blue car !
there is certainly more than one way for skinnin' the Cat , and there must be certainly more elegant ones ........
this one is rofl solution , only one which I'm capable to rethink in this moment
anyway - concept is here , and I think that price for avoiding one cap is pretty high ....... going DC all the way is pretty much complicated if you are keen to use universal input stage ... and you see exactly that
DC offset on output will be issue , and you must find how much
maybe is best to use 47(50)R pot in place of 39R
there is certainly more than one way for skinnin' the Cat , and there must be certainly more elegant ones ........
this one is rofl solution , only one which I'm capable to rethink in this moment
anyway - concept is here , and I think that price for avoiding one cap is pretty high ....... going DC all the way is pretty much complicated if you are keen to use universal input stage ... and you see exactly that
DC offset on output will be issue , and you must find how much
maybe is best to use 47(50)R pot in place of 39R
Attachments
in your boots - I'll keep that cap in place ...... and forget about DC coupling
it's better to flip in polarity entire input stage , making it with DC coupling in mind from the start
edit:
A40 ring a bell ?
editedit
A40 , Aclass , Citation by Papa
just few examples as food for thought - just look at biasing technicues
it's better to flip in polarity entire input stage , making it with DC coupling in mind from the start
edit:
A40 ring a bell ?
editedit
A40 , Aclass , Citation by Papa
just few examples as food for thought - just look at biasing technicues
Attachments
Last edited:
Two reasons to get the cap away for two days
- First reason, caps can sound so different for example Black Gate versus Silmic or a good film capacitor
- Second reason, on the way I learn to observe the parts that do biasing
I wanted to write this, but you were faster and delivered already material, thanks again!
- First reason, caps can sound so different for example Black Gate versus Silmic or a good film capacitor
- Second reason, on the way I learn to observe the parts that do biasing
I wanted to write this, but you were faster and delivered already material, thanks again!
no need for thankssssss
also - observe feedback taking points/ways ;
that way DC behavior of output is much less critical
Gatestoppers
...... I was a little bit playing with the value of the gatestoppers in the output stage. Between 50 and 220 Ohm, the difference in the sound is big!
Why? I supposed these values to work in the range of 200 Mhz.
Is the brighter sound with 50 Ohm the result of an oscillation?
Any answer welcome!
...... I was a little bit playing with the value of the gatestoppers in the output stage. Between 50 and 220 Ohm, the difference in the sound is big!
Why? I supposed these values to work in the range of 200 Mhz.
Is the brighter sound with 50 Ohm the result of an oscillation?
Any answer welcome!
Hi to every one at DIY Audio.
I have just become a member, and been checking out all the cool stuff on the site (I swear I can literaly smell the solder fumes wafting from the pages !).
I have been mainly building recording type stuff for a while now, but me thinks it's time for a new amp !
Am posting here first as I think this new amp should be one of Nelsons BA-1's, the second I lay eyes on the circuit I fell in love with it at once (Zen looks cool as well).
Was a bit surprised to see that it seemed to me not that many folks are building them compared to lots of other amps, maybe it's just a bit slow off the blocks or maybe the thought of two dozen trannys bolted on to a miniature nuclear reactor is a bit scarey even for the hefty heat-sinkers at DIY Audio.
I built my last amp back in 1988 which was nailed to a plank (and even used at a few partys like that) for a few years untill boxed. Ever since then I have switched on this well behaved solid state box and simply enjoyed listening to music. In my nightmares however I have been terrorised by swarms of molten glass 300B's chasing me down endless tunnels of sound, "You must listen to us !" they all screamed, at an ear shattering 1/2 watt.
Anyway, when Nelson dreamed up the BA-1 he seems to have unknowingly mixed the prescription to cure my 300B anxietys for good.
Anough of this sillyness. I am pretty darn sure the BA-1 is THE 1 4 me, I would welcome any comments from BA-1er's out there as to how they think this amp might be suited to my main setup at the moment, which is:
-Thorens TD160B MKII, SME Model 3009, Goldring 1006
-DIY Phono Preamp
-Rotel RCD-965BX 1 bit (haven't even ever had it open)
-DIY Ben Duncan PAS-02 Preamp
-DIY Well Behaved Tranny Amp 30W'ish (soon to be BA-1?)
-DIY Richard McDonald Transmission Lines hard-wired with Van den Hul The Wind
I listen to almost every style of music (and spoken word)
there is, and may even use this with a tele setup in the future, so I like an honest and universal system.
I think the BA-1 might be great with the transmission lines, not sure how my PAS-02 would get on with it's inputs though, maybe fine maybe not.
I would be interested in hearing from the BA bunch and
any other members as to whether they think I might end up a single ended happy bunny. cheers Simon
I have just become a member, and been checking out all the cool stuff on the site (I swear I can literaly smell the solder fumes wafting from the pages !).
I have been mainly building recording type stuff for a while now, but me thinks it's time for a new amp !
Am posting here first as I think this new amp should be one of Nelsons BA-1's, the second I lay eyes on the circuit I fell in love with it at once (Zen looks cool as well).
Was a bit surprised to see that it seemed to me not that many folks are building them compared to lots of other amps, maybe it's just a bit slow off the blocks or maybe the thought of two dozen trannys bolted on to a miniature nuclear reactor is a bit scarey even for the hefty heat-sinkers at DIY Audio.
I built my last amp back in 1988 which was nailed to a plank (and even used at a few partys like that) for a few years untill boxed. Ever since then I have switched on this well behaved solid state box and simply enjoyed listening to music. In my nightmares however I have been terrorised by swarms of molten glass 300B's chasing me down endless tunnels of sound, "You must listen to us !" they all screamed, at an ear shattering 1/2 watt.
Anyway, when Nelson dreamed up the BA-1 he seems to have unknowingly mixed the prescription to cure my 300B anxietys for good.
Anough of this sillyness. I am pretty darn sure the BA-1 is THE 1 4 me, I would welcome any comments from BA-1er's out there as to how they think this amp might be suited to my main setup at the moment, which is:
-Thorens TD160B MKII, SME Model 3009, Goldring 1006
-DIY Phono Preamp
-Rotel RCD-965BX 1 bit (haven't even ever had it open)
-DIY Ben Duncan PAS-02 Preamp
-DIY Well Behaved Tranny Amp 30W'ish (soon to be BA-1?)
-DIY Richard McDonald Transmission Lines hard-wired with Van den Hul The Wind
I listen to almost every style of music (and spoken word)
there is, and may even use this with a tele setup in the future, so I like an honest and universal system.
I think the BA-1 might be great with the transmission lines, not sure how my PAS-02 would get on with it's inputs though, maybe fine maybe not.
I would be interested in hearing from the BA bunch and
any other members as to whether they think I might end up a single ended happy bunny. cheers Simon
Hi Dave
Thanks for your interest in the Transmission Lines.
Am just getting the hang of the site.
That was my 1st post.
Am not quite sure how to start a thread just yet.
Hopefully I will become a pro poster soon enough though.
I saw the links at the bottom of your message.
Are you a Transmission Line fan?
Simon
Thanks for your interest in the Transmission Lines.
Am just getting the hang of the site.
That was my 1st post.
Am not quite sure how to start a thread just yet.
Hopefully I will become a pro poster soon enough though.
I saw the links at the bottom of your message.
Are you a Transmission Line fan?
Simon