Cascading Rangmasters no bueno ,why?

[Brymus]

I was trying some rangemaster versions,mods,transistors.
I was actually comparing the PNP version to NPN version ,and newer Russian Ge's to Mullard Ge's to Si
That was educational.
Absolutely no noticable differance except for the different gains used.
I did at first think that the mullard OC81 sounded better than the Russian Gt311,Gt313,GT402,Gt404
But later decided it was the gain and leakage after finding Russian ones that were close (they sounded the same to me)
I liked gains above 130 for my Rangemaster sounds although lower gains sounded good too they sounded especially nice above 130 IMO

I also though hey one RM sounds killer maybe two would sound twice as gainy and chewy.
When I tried cascading two together it was just noise.
I thought it may be power supply issues,so I made two seperate units on my breadboard,each with it's own power supply.
(one 9v the other 12v) well 9.25v and 11.8v actually.
Both sounded like perfect rangemasters used seperatly but cascaded together they just had unreal noise.
Two seperate units were slightly better than one that shared a single power supply, but not at all like I expected.

So what gives ? why do two Rangemasters sound REALLY awful when one sounds great ?
Silly question, but one I have no answer for.

[R.G.]

Both sounded like perfect rangemasters used seperatly but cascaded together they just had unreal noise.

Thermal noise and excess noise, which together account for most of the "hiss" yous hear, have their power increasing as frequency goes up.

Rangemasters are fundamentally gain stages with bass cut - that is, they amplify high frequencies much more than low frequencies. This makes them hiss magnifiers.

Any hiss in the first stage is amplified disproportionately by following stages, making the hiss much worse than either stage by itself.

[Brymus]

Thanks RG,
So maybe a low pass filter between the two ?
To keep everything above 4-5khz from getting amplified in the second RM.
With the first one using a larger input cap.

One thing I was trying was a set of mis matched diodes (1n34, 1n5711)at the output of the first RM on a switch.
This clamps the output and adds a bit of asymetrical clipping as well.
It sounds really good like this with the input caps (.0047 .022) on a switch too.
I was hoping to use the second RM as a recovery stage/top boost.
Just didn't work at all like I thought it might.

Another sound comparison I did was comparing M150s to regular AVX box,and Panasonic chicklet style, film caps.
I notice a lot of mojo builds with fancy caps.
And have heard for myself the M150's vs orange drops in my tube amps.
But I couldn't hear a bit of difference when they all had the same values.
Using two identicle RM circuits on the breadboard.
I was shocked...
I really expected the M150s to be noticably different at least.
But not to my ears.

[PRR]

> one RM sounds killer maybe two would sound twice as gainy and chewy.

Multiply. FOUR times.

Actually, since RM has gain of maybe 100, two in cascade is gain of 10,000

> one RM sounds killer maybe two would sound twice as gainy and chewy.

Drinking two beers may be good. Drinking 10,000 beers may not be so good.

I don't think a high-cut will do any until it CUTS almost all the multiplied gain away.

The RM designers had some sense (or try-and-see). If a couple more stages were "better", they could have sold that as a higher-price DeLuxe product. Evidently there is a "best" gain. Too little is not-enough, too much is TOO-MUCH. You may dink around their selected gain to suit your taste, but like 0.5 and 2.0, probably not 100X.

Yes, gain of 10,000 into 100mV sensitivity amplifier gets inptu sensitivity near 10 microVolts. Input random noise is liable to be 5 microvolts RMS, so 50uV peaks. The amp will be FULL OUT HISS.

[askwho69]

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[Brymus]

Hah
I think I may dub my RM clone 100 beers 
Then I can tell people I wanted to call it 10,000 beers but it didnt work.

Yeah I had my fun,didn't find any mojo or magic caps,or mystic trannies.
I did find gain, bias, and frequency response more subject to part value than part origin or the year it was born.
So now I can actually build one and not worry I didnt use the right mojo parts for a real Rangemaster clone.

I have moved on to comparing FF circuits just like I did with the Rangemaster.
But thats another thread.

I have noticed one type of Russian ge's will bias right up in the Dallas Arbiter version but not the JH2 modded version.
And the opposite is true for another type of Russian Ge's they bias right up in the JH2 circuit but not the Arbiter.
I really dont expect to find anything mojo magic wise but the Russian ge's definetly sound better than any FF Si circuit I have tried.
When I get to the PNP versions I will compare with the Mullards again,but I really expect gain and bias to be the keys to a good FF not rare name brand germanium parts.

[R.G.]

I did find gain, bias, and frequency response more subject to part value than part origin or the year it was born.
So now I can actually build one and not worry I didnt use the right mojo parts for a real Rangemaster clone.

I keep preaching this.
- There are no magic parts - only parts with strange values/properties and parts you don't yet understand.
- Magic - of which the various versions of mojo are special cases - does not happen in the real world. It happens inside a human head.
- In the music industry, magic/mojo is primarily an advertising and sales tool.

The Rangemaster is practically a textbook case for why parts values and the resulting gain, bias, frequency response matter and any magic quantities purported to reside in the parts do not. It's the poster child for advertising hyperbole.

When I get to the PNP versions I will compare with the Mullards again,but I really expect gain and bias to be the keys to a good FF not rare name brand germanium parts.

Me too. It's always good to do your own experimentation, but "The Technology of the Fuzz Face" and it's explanation of what makes the transistors/parts sound good has been corroborated for over a decade and over many thousands of Fuzz Face descendants.

[askwho69]

I keep preaching this.
- There are no magic parts - only parts with strange values/properties and parts you don't yet understand.
- Magic - of which the various versions of mojo are special cases - does not happen in the real world. It happens inside a human head.
- In the music industry, magic/mojo is primarily an advertising and sales tool.

this is very nice! why would i buy expensive parts when sound are the same, mojos' its all in the head? hehehe go green mylar!