Ok, it was just that the jfet input circuits looked identical (SE vs BAL)......by a quick look......and the "secret" was how the Cinemag was connected SE vs BAL).
Then I imagined that maybe the SE Cinemag connections could be "tweaked" to BAL......
But I will wait for a BAL kit to show up and "play" with SE until then.......and use it "as-is".
Then I imagined that maybe the SE Cinemag connections could be "tweaked" to BAL......
But I will wait for a BAL kit to show up and "play" with SE until then.......and use it "as-is".
everything is possible, even wooden stove
though, in case of Iron Pre, take Bal one and you have covered all scenarios and needs
only one thing missing from SE , that being straight 12db gain option
but then, this is costing more, while singing much worse:
though, in case of Iron Pre, take Bal one and you have covered all scenarios and needs
only one thing missing from SE , that being straight 12db gain option
but then, this is costing more, while singing much worse:
It's because there was someone between you and myself. You missed it by one kit. Sorry, man.
Earlier when you posted that there were 7 people before you, I had 5 people before me.
You all know I have no shame when it comes to admitting when I truly haven't the foggiest of ideas around a topic, but I will try...
Someone asked me why the switch for input selection should be a make before break and wanted a bit of an explanation in terms. I have no idea at all if I got it right... maybe someone could check my work, please. I don't want anyone to go down the wrong path.
-------------------------
Make... and Break... what does each word mean?
Make => Make the new connection. Close the open circuit
Break => Break the old connection. Open the closed circuit
You can make before break. Make the new connection WHILE for a moment the old connection is not broken yet.
OR
You can break before make. You break open the old connection before creating the new one.
In this case, we want to avoid the situation that would be kind of like unplugging and plugging in a new input w/o turning off the power each time you change inputs. You can get nasty pops. We want the circuit to feel like it always has an input plugged in even when we switch to the new input. That is not technically perfect, but it is meant to provide the 'feel' for what we're trying to accomplish.
You would never unplug your input from input 1 and plug it back in to input 2 with your pre-amp on... this avoids doing that when we switch between inputs.
Here is a nice video I found that I think does a better job that I can of explaining the switch.
https://www.google.com/search?q=mak...&ie=UTF-8#kpvalbx=_S7hvZPaRPOyKptQP5piSkAk_36
Someone asked me why the switch for input selection should be a make before break and wanted a bit of an explanation in terms. I have no idea at all if I got it right... maybe someone could check my work, please. I don't want anyone to go down the wrong path.
-------------------------
Make... and Break... what does each word mean?
Make => Make the new connection. Close the open circuit
Break => Break the old connection. Open the closed circuit
You can make before break. Make the new connection WHILE for a moment the old connection is not broken yet.
OR
You can break before make. You break open the old connection before creating the new one.
In this case, we want to avoid the situation that would be kind of like unplugging and plugging in a new input w/o turning off the power each time you change inputs. You can get nasty pops. We want the circuit to feel like it always has an input plugged in even when we switch to the new input. That is not technically perfect, but it is meant to provide the 'feel' for what we're trying to accomplish.
You would never unplug your input from input 1 and plug it back in to input 2 with your pre-amp on... this avoids doing that when we switch between inputs.
Here is a nice video I found that I think does a better job that I can of explaining the switch.
https://www.google.com/search?q=mak...&ie=UTF-8#kpvalbx=_S7hvZPaRPOyKptQP5piSkAk_36
Last edited:
Well.. 4 😉
Two power for dual mono and two signal (the CineMags included)
Edited to Note - Dual mono is not required, but it was intended to be built that way.
Two power for dual mono and two signal (the CineMags included)
Edited to Note - Dual mono is not required, but it was intended to be built that way.
Another question about transformers:
Would this toroidal be ok (good enough, quiet enough)?
RS PRO 230V ac, 2 x 18V ac Toroidal Transformer, 30VA 2 Output (671-8946)
Would this toroidal be ok (good enough, quiet enough)?
RS PRO 230V ac, 2 x 18V ac Toroidal Transformer, 30VA 2 Output (671-8946)
20VA Donut for Iron Pre SE, that's enough
10VA Donut per channel for Iron Pre (Bal), that's enough
you can build Bal with one mains Donut - but better to have it dual mono, if it's already everything done to allow that
@ItsAllInMyHead
MakeBeforeBreak switches (if Lorlin - having "S" mark on back, in between soldering pins) - establishing new position connection and then breaking previous one ; simply preventing clicks in speakers when switching different inputs; that being from fact that input is never left floating
OK, there is "mute" position (most left on rotary switch) but that is really just a gimmick trick, made for fun and whynot; no relay engaged, so input is really floating; maybe one can use it to listen how much electric garbage is in air around
10VA Donut per channel for Iron Pre (Bal), that's enough
you can build Bal with one mains Donut - but better to have it dual mono, if it's already everything done to allow that
@ItsAllInMyHead
MakeBeforeBreak switches (if Lorlin - having "S" mark on back, in between soldering pins) - establishing new position connection and then breaking previous one ; simply preventing clicks in speakers when switching different inputs; that being from fact that input is never left floating
OK, there is "mute" position (most left on rotary switch) but that is really just a gimmick trick, made for fun and whynot; no relay engaged, so input is really floating; maybe one can use it to listen how much electric garbage is in air around
@6L6 ......... still no Build Giude!!
it's really irresponsible from him to give priority to flying and "real life", instead of putting all energy in Real Audio Life
OK, I can only imagine how flying can be addictive
it's really irresponsible from him to give priority to flying and "real life", instead of putting all energy in Real Audio Life
OK, I can only imagine how flying can be addictive
I'm building an SE, but at RS the 20VA is three times the price of the 30VA. So, I'm tempted to just go with the 30VA.
Block 115 V ac, 230 V ac, 2 x 18V ac Toroidal Transformer, 20VA 2 Output
do your best, choose what's available and don't look back
in case of induced hum , you know the drill - if ham can can't help, move Donut out
disclaimer - I had a trouble free build of Iron Pumpkin with 2pcs of 30VA EI xformers inside the case
so, all you need is some luck to not end with hummng Duds
in case of induced hum , you know the drill - if ham can can't help, move Donut out
disclaimer - I had a trouble free build of Iron Pumpkin with 2pcs of 30VA EI xformers inside the case
so, all you need is some luck to not end with hummng Duds
Both models of Iron Pre are now sold out. I'm stopping the email sending process, and when the next batch is produced those who missed out will be first in line.