Switchable Hi-Z input impedance, how ?

[Simon B]

.......Tonestack Calculator from Duncan Amps. It is free and very useful for setting up different resistance and capacitance......

Hi Tinitus,

I'll second shanx in recommending TSC, in case you haven't tried it. It offers a fixed, useful set of topologies; component values can be changed easily (double-click and dialog box) and the results observed. It's also (almost too much) fun to play with.

Features

Download

 

[tinitus]

thanks
I have tried
but all I get uploaded is computer software codes

btw
got my old Creek head amp back
and is now connected to my bass rig
it works, with some connector mods

 

[Simon B]

..all I get uploaded is computer software codes..

Mmm, see what you mean.....my browser does the same (? see below) if I left-click on the download link. Usually, though not always, clicking on a link to a file makes the browser ask if I want to open it or save it. Some inner mystery of http I suppose.

What works for me is this: On the download link do a right-click, which should make a context menu appear, then left-click on the "save link as" or "save file as" (whatever variation on this theme your browser gives you). This should tlet you save it to your machine. You can then run it by double clicking it - you might want to virus scan it first, just in case. Hope this helps. Nice do-the-job toolmaking earlier on btw.

 

[tinitus]

thanks Simon, but I give up
managed to get it into a paint file
I have some friends who might be able to help me further

 

[tinitus]

thanks Simon, it works now

 

[tinitus]

setup gets weirder and weider
Creek head amp and compressor, nothing else
well, and my old LC Audio hifi stereo amp, to make it worse

the neat trick is that the head amp is only amplifying the top(midrange horn and CD)
and is adjustable
heh, it works great, best yet

 

[Simon B]

Weird? Nuts! It's an instrument amp setup - if it works for you to play through, then "That's the way to do it!" (c) Mr Punch 1891.

Anyway, if you want a weird competition 🙂D), I'll debar myself from audiophile land forever (as if I hadn't already!) by revealing that my all time best hifi listening setup has a pair of AR-18s atop my lovely big old JBLs........close your eyes and you're in front of a proper PA stack.......

 

[tinitus]

Hi Tinitus,
If you are having problems with tone stack, maybe you should download Tonestack Calculator from Duncan Amps. It is free and very useful for setting up different resistance and capacitance. There are a lot of styles too, fender type vox, marshall. You could ''tune'' the response curves for bass. Are you getting too much signal attenuation on your tone controls?

Hi Tinitus,

I'll second shanx in recommending TSC, in case you haven't tried it......It's also (almost too much) fun to play with.

It's also (almost too much) fun to play with.
😎🙂

 

[tinitus]

and finally arrived, a few of things that kept me waiting, and babling

 

[tinitus]

unfortunately I ordered the wrong tube sockets 😱
seems I will have to use the ones I got with the Broskie kit
but at least thats in the clear now, and I can finally get on with it

 

[shanx]

Hi Tinitus, I hope the build is going well. Did you finalize your front panel controls? or still working out the details? The PCB looks good ..too bad for the socket, but sure you will get it up and running.

 

[tinitus]

hey, finally got the tube anode and heater supply together, and mounted, with 'alternative' standmounts

 

[tinitus]

Did you finalize your front panel controls? or still working out the details?

the downloaded software to determine tone control plays a very important role in that part
I definately want them on the front panel now 😉

btw, I now connect my bass effects like in below layout
works ok to have the bass EQ on woofer only
but I had to solder some Jacks to RCA connects to make it possible
not optimal, but tells me Im on the right track here

 

[tinitus]

6n6p on top of 6n1p sounds almost ideal to give the desired lower voltage on 6n1p, and good drive from the top 6n6p

 

[tinitus]

man, these tubes are really pulling me round by the nose sure hope it will be worth it 😎

anyway, a few new pics
trying to 'exploit' the many possibilities of this kind of chassis
mounting mains wire, fuse holder, and trafo shield wire to chassis/ground

 

[tinitus]

man, everything seems have gone wrong with my tube heaters

very nice trafo with CT (6,6-3,3-CT-3,3-6,6)
but whats the use when I choose a tube with no CT point (6n1p)
and even worse, having a DC heater supply with no CT either
feels plain stupid

 

[tinitus]

hmm, I suppose I can simply ground trafo CT directly
using 3,3-CT-3,3
and then connect the 0-6,3V DC from heater supply directly between pin 4 and 5
and not ground it any further
would be 'floating', and ok, yes ?

 

[Simon B]

.......and then connect the 0-6,3V DC from heater supply directly between pin 4 and 5 and not ground it any further would be 'floating', and ok, yes ?

Or create a substitute "centre-tap" with a pair of resistors, say 330R each. One to each heater connection, the junction of the two resistors to ground, or at least a signal ground via a big cap fed with a suitable voltage through a resistor if the valves whose heaters are being fed by this have Vk too high for the Vkh rating of the valve otherwise.

 

[tinitus]

Or create a substitute "centre-tap" .....

and not use the trafo CT at all ? or both ?

 

[tinitus]

ah, I forget that that the CT was 'ordered' for the possible need to use
elevated heater voltage, in case of doing a mu follower etc
though some claim the artificial resistor CT is better 'balanced'
but whatever
and I just now read that elevated heater actually also does have positive effect on lowering hum 'issues' even further