Anyone have pictures of the board for this etc... The link roseblood11 posted is now dead

Bajaman, why did you choose the 2SK117 originally?

FWIW... I have thrown together a simulation of this circuit and it does function as described in the article. Haven't had a chance to actually build it yet tho, hopefully soon. I'm excited to see how it sounds.

I'm curious if anyone has played around with this novel approach to JFET emulation of a triode, it looks very interesting. The schematic and theory of its function are towards the bottom of this page. http://www.lynx.bc.ca/~jc/transferCurvature-TubeSimulation.html Here is a link to further discussio...

Thanks for sharing your work john. OH! I see it now. The schematic shows a circuit designed for a 16 ohm load but the BOM lists parts for building an 8 ohm load version. Thant's why all the values listed are halved. If anyone has any clear pictures of the inside of either the Richter or the Motherlo...

Hi, Can you post the Link to the other forum so I can get the rest of the conversation around the subject. This may shed some additional light. Thanks John Here http://www.rig-talk.com/forum/viewtopic.php?f=3&t=104175 about half way down And some (prob more useful) discussion here too... http:/...

That's what I meant to write 335R.
I guess I shouldn't be posting while crunching other numbers at work...

I found this schematic on another forum and need a little clarification if anyone is up to it. What i'm confused about is that the schematic shows two resistors in parallel across the transformer labeled 670R but the parts list states 330R. If these were in parallel as shown it would result in 165R....

Forgive me if I missed something but does anyone know what transistors are used in the positions listed below. I dont see specifications for these anywhere in the notes.

Q1
Q2
Q4
Q7
Q9
Q10
Q12
Q13
Q15

So I own a KOT V4 with the high gain mod on the red side and I finally got around to opening it up tonight to see whats going on with this high gain mod. The first thing I did was use some denatured alcohol and a brush to remove the sharpie marker from the op amp. To my surprise the chip used on the...

ESR is short for Effective Series Resistance, you could think of it as an imaginary fixed resistor that is connected in series with the capacitor, inside the capacitor is a rolled-up sandwich of two long strips of Aluminium foil separated by a porous membrane which is impregnated with an electrolyt...

I met Alfonzo Hermida back in 2009 at the New York Amp Show and we talked tech for a while. One thing we touched on was actually just this topic. In reference to the zendrive he stressed that a key component to the feel of that pedal is due to the capacitors used in the power supply. Specifically he...

Thanks !
Are you 100% sure about where the traces from C4 and R10 terminate under the IC?
I'll make a schematic in Multisim today if I have time.

so they really got some fuzz chips made?? doesn't that cost a fortune? why would you bother to do something like that other than for use as a marketing tool? ease of construction I could see, but if they are getting it all assembled smd anyway, what's the point? oh yeah, to stop people from reverse...

Has anyone tried different tubes in their OTD?
I've got a NOS GE 5751 and a NOS Sylvania 12AU7 I'm gonna try when I get home tonight.

Hey guys. I just bought an OTD-100 STA brand new for $40. I'm really excited to dig in and get this thing sounding amazing. I was looking around on the web to get some info on the 3 versions (val, sta & pro) and came across this pic of the guts of the pro. It looks like there is a bit more going...

Hides-His-Eyes wrote:Probably uses Hollis' autobiasing circuit

You mean this? looks interresting, I'll have to try it out.

The fact that they use the term "proprietary circuit" leads me to assume it's more than just using SI transistors.

Just stumbled across this on the web. It appears to stabilize the effect of temperature on the transistors via a "proprietary circuit". Any guesses as to what's going on here?

Just bumping this up since its been a while...