tube Screamer 808 - 3 diodes.....

[ANDYEFFECT]

tube Scraemer 808 3 diodes..... 
 
which the best position for them?
3 options.

       D1     (   D2    +    D3  )

1) 1n914 - 1n4007 - 1n34a

2) 1n4007 - 1n34a - 1n914 

3) 1n34a - 1n914  - 1n4007

[Mark Hammer]

Options 1 & 2 will provide the smaller difference in clipping thresholds between positive and negative half-cycles.  I dare anyone to hear a reliable demonstrable difference between them.  Option 3 provides a greater contrast and *will* sound different than 1 or 2. 

None of these "sounds better", or provides something that can be called "more dynamics" or "more headroom".  Options 1 and 2 provide a little more headroom for one half-cycle than the other, while option 3 provides less headroom for one half cycle (compared to 1 and 2), but more for the other half cycle.

Their sonic impact will depend greatly on your picking style.

[brett]

Hi.
RE: I dare anyone to hear a reliable demonstrable difference between them.
I've always thought that my TS9 sounds better when switched to 3 diodes: 1N4148 <-> (1N4148+1N4148).  But maybe I'm imagining it. 

To test this more objkectively, I'll rope the kids in to help me do a blind test of 25 of each setting (randomly allocated), and see whether I can tell the difference. Chi-square test, maybe?  With 25 expected right and 25 expected wrong, and 49 degrees of freedom?  I'll check what test I should use.

cheers

[wampcat1]

Hi.
RE: I dare anyone to hear a reliable demonstrable difference between them.
I've always thought that my TS9 sounds better when switched to 3 diodes: 1N4148 <-> (1N4148+1N4148).  But maybe I'm imagining it. 

To test this more objkectively, I'll rope the kids in to help me do a blind test of 25 of each setting (randomly allocated), and see whether I can tell the difference. Chi-square test, maybe?  With 25 expected right and 25 expected wrong, and 49 degrees of freedom?  I'll check what test I should use.

cheers

What mark is saying is that having the 1n400x or the 1n4148 diode in that position will yield the same results unless you have superman hearing.


bw

[Mark Hammer]

Correct.

Differences between a 1+1 vs a 1+2 diode complement ARE noticeable, and useful, though subtler than many will expect to hear.

[cbriere]

The effect of 2 in series is a addition of octave up effect.
very subtle , but there.

This is acheive by one altrnance to be shorter than its opposite thus
creating octave up harmonic addition.
Cool hein!

[MartyMart]

My personal pref, is 1X 1N4148( or 914) and 1X 1N4001/4002 each way .... assym

MM.

[brett]

Hi.
Hey I did the blind testing on 2 vs 3 1N4148 diodes.  19 out of 20 times I rated the 3 diodes as "good" and the 2 diodes as "poor".  Only 1 time in 20 was I wrong (I rated the 2 diodes good).

Acording to a common statistical test for this sort of thing (the chi square test), the chances of this happening by chance are less than 0.1%.  From my perspective it was dead easy to tell when the 3 diodes and asymetric clipping were switched on, even though my kids were making multiple changes to the 2/3 diode switch and volume levels to try to disguide the effect.

The guitar was a Yamaha RGZ, the amp was an 18 watt lite (see www.18watt.com), and the speaker was a Sammi 12" 50W (excellent speaker!).

[petemoore]

  ME300B50
  http://www.sammisound.com/products/pro/03-10.htm
  Is this the component you Speakhere Of Brett?
  I didn't see the pricing page there yet...I have Greenback Speakers...looking for the Real "Real Deal" on raw speakers, and don't really wanna spend huge on Alnico Blue types.
  As far as diodes in TS types...anything works in there, but the only configuration that works in my TS thang is:
ll Two Ge's         --->l--->l--
ll And a 1n4001     ----l<---
  ...just Cuz...[that's what happened to end up there ]

[brett]

Hi Pete
That's the speaker.  Mine cost $70 Aussie dollars, which is about US$50.
In my opinion they have a very pleasant semi-vintage sound.  Not quite the same as a greenback or a greenback re-issue, but VERY nice in their own right.  Definately a better class of tone than the Eminence speakers I've tried a couple of times.  They are very efficient and my 18 watter drives a single one to reasonable sound levels (enough for a small club).  A 4 x 12 package would be quite awesome.

And no, they aren't paying me to say all this, but perhaps they should.