TomWaterman
Well-known member
I'm planning on offering PCB's - either that or maybe Gustav/Fabio can fab them at a later date. I think Fabio offered a long way back in this thread?
I want to fully test it out before I document the project to the group. I am currently deciding the best way to offer this.
Initially I was going to split the Pre and EQ up but leave the EQ unbalanced with an insert point into the pre before the output amp/TX. Now I'm going to leave facility for the EQ to be used stand-alone with either TX input or diff.in electrically balanced and an extra o/p fader. The pre will feature 990 footprint amps. I'm in the middle of sorting out an amp which is essentially like TK's GainBloaks (they share a similar topology to the Calrec B series amps) which are more heavily biased into Class-A and use common available transistors unlike the B amps.
The EQ will have 990 footprint input buffer and output amp to drive TX. All filter amps are on the mainboard.
Input transformers can be mounted on-board and I plan to use Cinemag CMOB-2 outputs so there is a choice of steel, 50/50 or Nickel. I hope to compare the Cinemag Nickel to the Calrec Sowter Nickel one. The Sowter cannot PCB mount, is too big for one proposed format and its also very expensive at around £60 ($120!). So I think the Cinemags offer cool variety at the right price. If you get a 1061 from Averill they use Jensens on the O/P anyway as the transformers are mounted outside of the module when used in a console.
There are pads for tants or Radial Electros in coupling positions, (I'm planning on Elna Silmic/Cerafine).
Tants plus Steel for what I expect to be a more vintage tone and Radials plus Nickel for a more open sound. The idea is flexibilty - o/p tx choices, cap choices, amp choices....
The EQ should use Sowter Neve Inductors or DIY wound RM10/12 cores - pads for both.
Erm what else, I have pcb mounted switches and pots on pre amp plus maybe a tricolour led meter based on PRRs musings a while back....if I sort it.
Not sure whether to pcb mount eq switches as it ties user into a specific switch.
Now the crisis I'm having at the mo is:
What formats - I wanted to make it such that one could do a full strip or a pair of pres or EQs in 1U, 2 full channels or 4 pres in 2U with 6-8ch of pre or EQ in 3U. err horrible sentence that! :green:
However I have also been planning on a sub-rack system. I got a spec for one in my mind which turns out to be similar to the modules TK at vintagedesign is offering but 6+1ch in 3U instead of 8.
Module spacing would be the same as the new Chandler stuff:
However there is talk behind the scenes of an open standard backplane that offers everything needed and then some. It would be a great platform for DIYers to grab a hold of when it arrives. So I'm not sure whether to go for that.....aghhh only prob is it will likely be 8 ch and require slightly smaller more expensive switches such as Elma01 to fit....
how would you like to build yours? What appeals to you?
I could use the clarity as this spins around in my head and I can't really talk to anyone to get it out!!! My GF doesn't understand this stuff - just stares at me with the sound of wind flowing thru her brain!
Aghhh I'm blabbering.......gotta go fire up the BBQ!! woo
-Tom
I want to fully test it out before I document the project to the group. I am currently deciding the best way to offer this.
Initially I was going to split the Pre and EQ up but leave the EQ unbalanced with an insert point into the pre before the output amp/TX. Now I'm going to leave facility for the EQ to be used stand-alone with either TX input or diff.in electrically balanced and an extra o/p fader. The pre will feature 990 footprint amps. I'm in the middle of sorting out an amp which is essentially like TK's GainBloaks (they share a similar topology to the Calrec B series amps) which are more heavily biased into Class-A and use common available transistors unlike the B amps.
The EQ will have 990 footprint input buffer and output amp to drive TX. All filter amps are on the mainboard.
Input transformers can be mounted on-board and I plan to use Cinemag CMOB-2 outputs so there is a choice of steel, 50/50 or Nickel. I hope to compare the Cinemag Nickel to the Calrec Sowter Nickel one. The Sowter cannot PCB mount, is too big for one proposed format and its also very expensive at around £60 ($120!). So I think the Cinemags offer cool variety at the right price. If you get a 1061 from Averill they use Jensens on the O/P anyway as the transformers are mounted outside of the module when used in a console.
There are pads for tants or Radial Electros in coupling positions, (I'm planning on Elna Silmic/Cerafine).
Tants plus Steel for what I expect to be a more vintage tone and Radials plus Nickel for a more open sound. The idea is flexibilty - o/p tx choices, cap choices, amp choices....
The EQ should use Sowter Neve Inductors or DIY wound RM10/12 cores - pads for both.
Erm what else, I have pcb mounted switches and pots on pre amp plus maybe a tricolour led meter based on PRRs musings a while back....if I sort it.
Not sure whether to pcb mount eq switches as it ties user into a specific switch.
Now the crisis I'm having at the mo is:
What formats - I wanted to make it such that one could do a full strip or a pair of pres or EQs in 1U, 2 full channels or 4 pres in 2U with 6-8ch of pre or EQ in 3U. err horrible sentence that! :green:
However I have also been planning on a sub-rack system. I got a spec for one in my mind which turns out to be similar to the modules TK at vintagedesign is offering but 6+1ch in 3U instead of 8.
Module spacing would be the same as the new Chandler stuff:
However there is talk behind the scenes of an open standard backplane that offers everything needed and then some. It would be a great platform for DIYers to grab a hold of when it arrives. So I'm not sure whether to go for that.....aghhh only prob is it will likely be 8 ch and require slightly smaller more expensive switches such as Elma01 to fit....
how would you like to build yours? What appeals to you?
I could use the clarity as this spins around in my head and I can't really talk to anyone to get it out!!! My GF doesn't understand this stuff - just stares at me with the sound of wind flowing thru her brain!
Aghhh I'm blabbering.......gotta go fire up the BBQ!! woo
-Tom
