NZGuitars.com : Filling you with GAS since 2003

The rattling clipping is probably blocking distortion from all that gain. You might tame it by just adding a 22k grid stopper to v2. Also, you can ditch the 10nf cap on the volume wiper - it might be contributing to the blocking and it’s not needed, unless you want some sort of high-pass RC filter ...

If you like the sound then leave the anode resistors alone and maybe just fiddle with the cathode resistors on v1&2. But there’s nothing that says you have to be centre-biased and your current settings aren’t hurting anything. There are some unruly clipping sounds occasionally, bit like a rattl...

Shouldn't that Treble control wiper be on the other end of the 50nF Cap ? Screen Shot 2024-09-11 at 11.30.59 AM.jpg I shall try that but I was thinking of putting a Fender/Jansen 4/12 tonestack in between V1 and V2. I find the treble too shrill at the moment and the bass not enough. I calculate the...

Remember that I thought the current iteration has TOO MUCH GAIN.... I have now updated the circuit diagram to reflect the changes I made and document actual resistor component values, regardless of what the colour bands tell me they should be. Two resistors jump out :crazy: Power supply changes: A, ...

That is utterly terrifying! :shock: :shock: :shock: :shock: ... but makes for compelling reading :clap: Hey, you are back :wink: I am honoured you are reading this humble thread. Wasn't there a dude in Christchurch who's hobby it was to convert old radios to guitar amps? Haven't seen him posting fo...

So I added one extra 6AV6 stage which means that two triodes are amplifying the guitar signal before it goes to the power stage. THERE IS TOO MUCH GAIN NOW.!! More on that later but the amp sounds rather interesting :D Those 6VA6 triodes are quite something. I also increased headroom for each stage ...

Pseudo science here...

Total current in radio would have been something like this:

I know the rectifier is an EZ xx. The EZ80 is limited to 90mA and the EZ81 to 150mA.

Therefore, according to max calculated current, it must be an EZ81

So here is the original circuit diagram for the Philco Radio amplifier section for one channel. Both channels are identical. Note the grid leak biasing for the 6AV6, the peculiar powering of section B and C and the odd treble circuit. Lots of things have been changed since :D 20240905_183223.jpg

RectifiedAmps wrote: ↑Thu Sep 05, 2024 5:08 pm 6AV6 are awesome for guitar if you get them set up right! 7-pin tubes have extra special mojo…

There is certainly a vibe to this amp, two of them in 'series' is driving the EL84 super hard.

I found some info on the web about Philco radios and it looks this one is from the early sixties. Showing grid leak valve biasing for the pre-amps :lol: The valve complement is as follows: RF department - 2 x EF89 plus 1 x ECH81 Pre amp section - 2 x 6AV6 (single triode miniature valve), one for eac...

GrantB wrote: ↑Thu Sep 05, 2024 11:59 am

Jay wrote: ↑Thu Sep 05, 2024 7:50 am Do I see that right? Only a zero and 2nd fret? All the rest is just wood?

If so that would explain the tiny bridge as intonation is not realy that important anymore.

Looks like frets on each maunga!

yeah, phone screens and eyesight.

Thought I put this transformation in a dedicated thread. I was visiting a friend who was loading up his trailer with stuff for the dump when I saw this discarded radio chassis. He said I could have it and he had the valves somewhere in a box. So I went home with a new project, not expecting too much...

Do I see that right? Only a zero and 2nd fret? All the rest is just wood?

If so that would explain the tiny bridge as intonation is not realy that important anymore.

Transforming a 1960s? radio into a single ended guitar amplifier. ... fun project

Edit - project here: https://www.nzguitars.com/forum/viewtop ... 41&t=43162

jeremyb wrote: ↑Thu Aug 29, 2024 7:04 am I'm kinda hoping with the bass lessons that it will also improve my guitar playing, any thoughts? the focus on feeling the groove and working on timing will definitely cross over...

Soon you should also be able to name any note on the fretboard on the fly