hope I put , then , 7812 ....... or you're going to be in trouble
take care of D7 value on channel pcbs
(enough) for that at a time
7812, yes you smart : ),for D7... i´ll look it up tomorrow, i think i activated brain and checked it and its ok...
R9 R10 shunt reg
before biasing buffer, guess the shunt reg has to be set.
-Can we measure it (12V) on the V+,V- pads on PCB?
-Is poti (R9/10)preset critical?
I´m always afraid of first powering up
tnx
stefan
before biasing buffer, guess the shunt reg has to be set.
-Can we measure it (12V) on the V+,V- pads on PCB?
-Is poti (R9/10)preset critical?
I´m always afraid of first powering up
tnx
stefan
yup , I've put these pads there exactly for measurements purpose......
if you're sure in your work (parts placement etc.) and properly set trimpots in buffer (lower one-CCS- set to max ) just bang it ....... set Good Gemini voltages (+/-12Vdc) , and then proceed to setting output buffers
of course - connect Turtle to channel pcbs only when you already set buffer DC output offset
edit: I personally prefer straight buffer schm to Borbely WCF iteration ; that way IP is in invisible mode , just as I like it 🙂
if you're sure in your work (parts placement etc.) and properly set trimpots in buffer (lower one-CCS- set to max ) just bang it ....... set Good Gemini voltages (+/-12Vdc) , and then proceed to setting output buffers
of course - connect Turtle to channel pcbs only when you already set buffer DC output offset
edit: I personally prefer straight buffer schm to Borbely WCF iteration ; that way IP is in invisible mode , just as I like it 🙂
that was superconvenient : )
shunt regs were about 12,5 initially, easy to trim.
initial bias was about 17 mA, easy to trim to 21mV across R34 also. I was at least clever enough to leave some hight on R34 for easy measuring.
Offset also easy to trim!
few hours finishing ...: )
best
stefan
shunt regs were about 12,5 initially, easy to trim.
initial bias was about 17 mA, easy to trim to 21mV across R34 also. I was at least clever enough to leave some hight on R34 for easy measuring.
Offset also easy to trim!
few hours finishing ...: )
best
stefan
and let us know how you like it
I know that you prepared superduper case , and I know that you know how to make proper porn
problem is just force you to post it , along with porn from Venice
I know that you prepared superduper case , and I know that you know how to make proper porn
problem is just force you to post it , along with porn from Venice
: ), yah, you know me. Porn a bit later,
a little already asked question again (sorry for that, couldn´t find it with search).
I asked for using a stereo plug (for i-pods etc), and how to manage (separate) the common ground on those plugs.
Your recommendation was to put a resistor in gnd to one channel? About 100 Ohms?
tnx!
st
a little already asked question again (sorry for that, couldn´t find it with search).
I asked for using a stereo plug (for i-pods etc), and how to manage (separate) the common ground on those plugs.
Your recommendation was to put a resistor in gnd to one channel? About 100 Ohms?
tnx!
st
10-15-22
as low as you can , without making huuuuuummmmm
though , first try with regular cable , this drek is floating anyway ( no connection with safety gnd) , so most probably no gnd loop
anyway , there are ntcs in IP , so ground loop is hardly possible, whatever you connect to input
as low as you can , without making huuuuuummmmm
though , first try with regular cable , this drek is floating anyway ( no connection with safety gnd) , so most probably no gnd loop
anyway , there are ntcs in IP , so ground loop is hardly possible, whatever you connect to input
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damned, i have appointment now and to leave.
it sings : )
i have just one set RCA cables (from COmputer) pluged in. When i dial another source (so empty RCA on Preamp) i have a quite a loud distorted signal (on all other souces/emty RCAs). turning the pot does not change Level of distorted signal. When i pull out one RCA plug there is just undistorted signal on the chosen source...and complete silence on the other sources..
shure it is some signature stupidness i made : )
Will have a fresh eye tomorrow.
Ah, it was a bit fusehungry in the beginning, but now seems to be ok...
more tomorow 🙂
it sings : )
i have just one set RCA cables (from COmputer) pluged in. When i dial another source (so empty RCA on Preamp) i have a quite a loud distorted signal (on all other souces/emty RCAs). turning the pot does not change Level of distorted signal. When i pull out one RCA plug there is just undistorted signal on the chosen source...and complete silence on the other sources..
shure it is some signature stupidness i made : )
Will have a fresh eye tomorrow.
Ah, it was a bit fusehungry in the beginning, but now seems to be ok...
more tomorow 🙂
post some pics and I'll help ; you certainly swapped gnd and hot somewhere
as I made it - all unused inputs are hard grounded , only used input is open and connected to buffer input
fuse-hungry - Donut I sent you is 30VA , so with 230Vac mains , it calls for 120mA-160mA ...... both F and T will do ...... better F
as I made it - all unused inputs are hard grounded , only used input is open and connected to buffer input
fuse-hungry - Donut I sent you is 30VA , so with 230Vac mains , it calls for 120mA-160mA ...... both F and T will do ...... better F
you want it as far is possible from Turtle
of course that you can glue it even on top of Turtle itself , but don't ask me then why poor creature is humming
of course that you can glue it even on top of Turtle itself , but don't ask me then why poor creature is humming
dear ZM, had some time to comb the signal hairlike cables and crosstalk is gone : )
Also fuse is staying. Maybe it was the caps conditioning or so.
Crazynice preamp. A real joy to make. Not just convenientwise (flatcables), also conceptwise, with good buffer, thank god presoldered jfets : ), a more or less custom made autoformer, the whole relaythingie and last not least, thank god no remote conrol 🙂
Also fuse is staying. Maybe it was the caps conditioning or so.
Crazynice preamp. A real joy to make. Not just convenientwise (flatcables), also conceptwise, with good buffer, thank god presoldered jfets : ), a more or less custom made autoformer, the whole relaythingie and last not least, thank god no remote conrol 🙂
you made some reallly big ookup with cables , if you had xtalk
as I said - inactive inputs are hard grounded ......
anyway , I like that you like it ...... and how you like sound (or lack of same ) of it?
🙂
porn?
(if you post some pics , maybe I can see is there something to optimize .......)
as I said - inactive inputs are hard grounded ......
anyway , I like that you like it ...... and how you like sound (or lack of same ) of it?
🙂
porn?
(if you post some pics , maybe I can see is there something to optimize .......)
