What's wrong with the kiss, boy?

[Dennis Hui]

Dear Mighty ZM,

A silly question: Am I correct that if I want to use Cinemags with your pcbs
then one would need to cut off pins 1,6,7,12 (the same way as with SissySIT)?

Thanks,
Dennis

 

[Zen Mod]

almost forgot to reply ....

yes , I believe so that you need to cut 4 outer/corner pins

though - it'll show itself when you try to align them on pcb

if needed , post few nice pictures with Cinemag on pcb and I'll explain what's necessary

 

[Dennis Hui]

Thank you.

 

[Zen Mod]

in fact , considering that those pins are NC anyway , nothing wrong if you cut them without much thinking

 

[Dennis Hui]

Hi Mighty ZM,

For the input buffer jfets, would higher Idss be preferable (say 10mA vs 6mA in
the BL range)?

Also, how high/low value for the pot is recommended? 100k Alps is available
at mouser and I think 20K and 50K at other stores.

Thanks,
Dennis

 

[Zen Mod]

higher Idss is OK , just keep an eye od dissipation (say no more than 150mW per JFet, more is making me nervous...if needed ,just increase resistance of source trimpot,, meaning - use first bigger value )

pot value - that's relevant to sources you have in front of pot - more cojones,lower pot value

so ,10Klog to 100K log

 

[Dennis Hui]

Thank you Mighty ZM! Should start stuffing board this weekend. 😀

 

[Dennis Hui]

Some progress has been made with most of the parts stuffed.
I've also found and picked out jfets for the buffer. For the transformer,
I'll likely use Cinemag (low nickel).

For the 14 pin header, is there a recommended part? The pitch seems
to be 2.5mm or 2.54mm. Would something like these be suitable?

DF1BZ-14DP-2.5DSA Hirose Connector | Mouser Canada

DF1B-14DS-2.5RC Hirose Connector | Mouser Canada

Thanks,
Dennis

 

[Zen Mod]

2.54

 

[Dennis Hui]

Thank you Mighty Zen Mod. 😀

 

[Zen Mod]

oh , btw.......

there is ongoing e-mail correspondence between Flying Jim (6L6) and Patrick A. (sorry, ZM didn't catch Patrick's Nick) and Mighty ZM ..... you can easily grasp how easily ZM is confused with e-mails flying between 3 of us .......

anyway , topic is final development of Iron Pre preamps ( both SE and non-SE) , mostly related to brushing up nomenclature , enabling all bells and whistles,helping with BOMs and preparing of Build Guide , enclosure(s) etc.

my part is finished (sch and pcbs) , so I'll post just teasers -- how final pcbs are going to look

hope I'm not stepping here on their toes ...... 🙂

edit: Diyaudio gave me so much during all these years , this is just a smidgen , me trying to give something back

 

[Zen Mod]

Iron Pre SE (hope is ) Final

.......

 

[Zen Mod]

Iron Pre (hope is ) Final

........

 

[Zen Mod]

Oh , yeah , there is flashy selector switch , too ......

6L6 asked for shiny LED function , too .......

 

[6L6]

No toes to step on! Looks beautiful!!

I’ll have a prototype run made shortly.

 

[Zen Mod]

who are you ?

 

[noviygera]

Is this a pre amp or what?

 

[Zen Mod]

well, ''Pre'' in title is somewhat hinting that ....... 🙂

but , anyway , that's line preamp stage , where you have selector (5inputs) followed with resistive attenuator (volumepot) , then followed by buffer (with reg. psu ) and finally autoformer at output ..... everything on board ;

SE iteration - both channels on one pcb , 3 different brands of autoformers applicable, settable gain 6db or 12db

Bal iteration - one channel- one pcb , 3 different brands of autoformers applicable, gain fixed 6db , arbitrary number of (fixed) SE inputs , rest to 5- Bal inputs, both SE and Bal outputs (active in same time) ; so , functioning as SE in/Bal out and Bal in /SE out converter , and normally as Bal in/Bal out stage

if I forgot something ........ just shoot

 

[indra1]

ZM, how about a 150+150 : 150+150 on 40mm nanocrystalline toroid transformer?

 

[Zen Mod]

tell me where to find them for cheap !!!!!!!!!