It was not created with the ROG techniques because the schematic of the VH4 is not known, so we created a preamp with a spectral analysis of an original VH4 to see which frequencies are typical of the VH4 sound (channel 3 & 4 ).
We worked 6 months on it to do the last schematic.
I don´t know what is a Diezel VH4 - does it sound like a V8-Diesel-motor ?
.... and the design still uses drain-trimmers - even at the source bypassed stages - which will cause every unit to sound different due to the different drain-currents....
If only the frequency response would be important, someone could use op-amps instead of the FET´s too...
analogguru
There´s a sucker born every minute - and too many of them end up in the bootweak pedal biz.
.... and the design still uses drain-trimmers - even at the source bypassed stages - which will cause every unit to sound different due to the different drain-currents....
If only the frequency response would be important, someone could use op-amps instead of the FET´s too...
It's the conception of the Jfet simulation: use drain trimmers and adapt them to 6v. (4.5v for 9v sim).
Feel free to upgrade but your method is to respect the frequencies of simulated stages BUT , we did'nt start from the schematic of the Diezel. (post 1 of this topic).
I followed the project on techniguitare. It is not a traditional simulation with the ROG method. In fact it does not stem from the schematic of the Diezel, but from the Dual Rectifier. Then a frequency analysis of a VH4 has been performed, in order to design a post-equalizer capable of mimicking the frequency response of this amp, and has been added to the Rectifet (the techniguitare version of the Dual Recto simulation).
Of course, it could be done with other devices, but that's how the project originated. Maybe in a future version ...
DSV wrote:I followed the project on techniguitare. It is not a traditional simulation with the ROG method. In fact it does not stem from the schematic of the Diezel, but from the Dual Rectifier. Then a frequency analysis of a VH4 has been performed, in order to design a post-equalizer capable of mimicking the frequency response of this amp, and has been added to the Rectifet (the techniguitare version of the Dual Recto simulation).
It was at the beginning, now it's a totally new preamp ! the post eq idea was abandonned for example
Yeah when I load that PCB file into photoshop it gives me an error. Standard photoviewers open it fine, but photoshop says something about missing data.
Just use the PCB and "Schematic" (which is actually the Layout map).
The PDF is pretty bad! Hard to read and fuzzy.
You could probably just print the schematic and compare it to the BOM and layout.
But why not just make a decent PDF huh?
The bass control is the same as the original on the VH4 (as the teble and middle)because we found the schematic of the tonestack, the deep control is also on the vh4 (see the user manual) it boost around 100Hz, and the extra control will decrease the bass level before the tonestack and the deep control.
.... and the design still uses drain-trimmers - even at the source bypassed stages - which will cause every unit to sound different due to the different drain-currents....
(on test!)
