pz wrote:phatt wrote:
Can't comment on Victor K except to say the When i tried to use discreet fets in the building of my tone circuits and like stuff ,,, well it worked but noise was a problem. Unless something stunning can be shown it really is much simpler to use a chip.
I bet, not noisier than the LXH Fender i just found in the drawer, built many years ago using prehistoric 741's
I haven't seen many build reports about these speaker sims, probably due to rather complex schematic and the lack of "vero".
So, as a reference and to add more data to this thread i have just recorded a short riff using my home build 4W tube amp and RLC dummy load straight into the LHX Fender cabsim.
Plus a real frequency response of the unit.
Personally i find the sound a little bit too dark.
Hi PZ, Thanks for sharing.
Yeah this stuff can be done in so many different ways it's easy for the novice to miss the detail.
You obviously have a Valve Amp to work with but other folks may only have a SS setup so you have to approach things in a different manner.
Re Valve outputs;
I did research a lot of the RLC stuff but (as I mentioned earlier in this thread)
I found it far simpler to implement a simple load R followed by a voltage division running into a graphic EQ > onto poweramp or direct to recording.
I agree that IF the tube amp delivers close to the required tone shape it takes little effort to get great things to happen.
Some tube amps will obviously need more tweaking and my Valve setup like yours does not need much to capture the tone.
In testing both my Reamplified Valve poweramp setup and my Hybrid SS setup there is only a slight improvement with the Valve powerstage soaked.
Examples;
1/ FPV (PhAbbTone) > DDC > Graphic > Old Laney Keyboard Amp.
2/ FPV (PhAbbTone) > Valve Amp > Load box > Graphic > Laney Amp.
(The Valve pwr stage does sing a little better.)
Both these setups reap very similar results and I negate a whole mine field of Mathematical RLC Gymnastics.
I went thru months testing all kinds of RLC stuff for Valve outputs and IMHO they are a pain to work with. Big clunky inductors, coneless speaker, iso cabs, the list goes on.
Sorry but Iza been around too long to waste time on stuff that just complicates a simple issue. A lot are overrated (for what they deliver) when an old HiFi Graphic can open a whole list of different results. I just added a switch and 2x 6.5mm sockets on the GEQ and threw the silly stuff in the bin.
Note For Valve Amps*
The Load R was my biggest hurdle until I found a small bit of text written by the maker (I assume) of the UA (Ultimate Attenuator).
(and without side tracking this too much)
The Load R is a big factor.
An 8 Ohm System needs around 3 to 4 times the R to match the Z so I use 24 Ohms Load R. this overcomes a lot of the RLC voodoo maths.
Using 8 R load just turns your Valve Amp into a fizzy SS sounding dirt box and kills any chance of sustain.
That's why simple Attenuators don't work you need to Re EQ and Reamplify it other wise they sound rather bland.
To give you an idea about the liquid sustain I wanted, Google *Guytron GT100*,,, that is the sound I wanted to achieve. (it's a Reamp All valve setup, 2 Amps in one box)
I feel that with some SS circuit tricks I maybe able to replicate the Guytron but the sustain is very hard to nail down when competing with all Valve.
I'm still not quite there but I'm getting closer. Winky.
Meantime back on topic,
The Valve front end (on Example 1 above) does a pretty good job and I use it more than the other. (One less box to cart around to gigs, Even small Valve Heads are heavy)
If I was to start all this all over again I would certainly take *KMG's* great work and test it out as it does look promising. But I have the liquid tone of Guytron implanted in my head and it won't go away easy.
I did actually try some of your circuits but it was so long ago I forget which ones,,, might of been the one with lots of opamps which I felt was getting way to complex for what I needed but hey It obviously works.
Phil.