Posted: Fri Feb 19, 2010 9:12 am
so you don't like any pedals?Mike wrote:Really not a fan of a pedal that sounds nothing like a natural amplifier overdrive.
so you don't like any pedals?Mike wrote:Really not a fan of a pedal that sounds nothing like a natural amplifier overdrive.
No need to be sorry old bean, it's all in the name of fun! Just wish I had put TS7 on the list!!!!benecol wrote:If ever there was a pedal poll less likely to get any worthwhile responses. Sorry old thing - not beloved of shortscale, the tubescreamer.
Reece wrote:this feels like a poll saying WHICH YEAR STRAT 61, 62, 63 OR 64?
i choose whichever one sounds the least like a tubescreamer.
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Model 808 9 9RI 10 5
Series res. 100 470 470 470 470
Shunt res. 10K 100K 100K 100K 100
o start with, the series resistance at the emitter limits the amount of drive available to drive an amplifier input (although not by much), and in concert with the series capacitor forms a voltage divider with the output shunt resistor and the input impedance of the amplifier plugged into it. This drops the available signal only a trivial amount, probably inaudibly so. The input resistance of a typical tube amp is most often 1M or over. This is not a serious contributor to the loading of the output follower.
However, the 10K shunt resistor load on the TS808 output does have an effect on the follower's operation. An emitter follower with a resistor load is often assumed to have a very low output impedance, which is true, as long as the signal is going up. However, when the signal is going down, the transistor can only turn off, and the signal is pulled down by the net loading, DC and AC on the emitter. The 10K shunt resistor effectively halves the emitter loading on the output buffer. This does two things; trivially, it reduces the input impedance of the emitter follower; more importantly it reduces the negative going output impedance of the stage by half to about 5K. This means that the output stage can drive the following stage off about twice as hard.
Can this account for the admittedly very subtle audible differences between the TS 9 and 808? It pretty much has to, as the operating current for both stages is the same, the series resistance is only trivially different compared to the forward biased input impedance of a triode grid (10's of K's for the typical duotriode input), and the voltage divider ratio difference between 100/10K and 470/100K is 0.990099 versus 0.995322, an inaudible amplitude difference.
In terms of differences among the models: the TS808, the TS9, and the TS9 reissue are in fact built on the same circuit board pattern. For these three, THE ONLY DIFFERENCES ARE THE OPAMP TYPE AND THE TWO OUTPUT RESISTORS. This is how the various conversions to "TS808 specs" are done - two resistors are changed in value, and the opamp maybe changed to another type. Conversions to "brown sound" or other mystical turbocharging are done by twiddling the values of the resistor and capacitor frequency determining components.
The TS5 is a circuit copy of the TS9, excepting the opamp and a few components in the bias supply section.
The TS10 is the "sleeper". Available on the used market for as low as $20 in working order, it differs from the TS9 In only a few ways:
* extra 220 ohm resistor in series with the (+) input of the clipping amp
* extra emitter follower in series from the input buffer amp to the JFET switch for the bypassed condition
* Different bias voltage for the input buffer transistor.
If you jumper the 220 ohm, clip out the extra buffer transistor and connect the jfet signal coupling cap to the emitter of the input buffer, and change one resistor in the input buffer biasing circuit, you have a working TS9 in the TS10 case. From there, two resistor changes get you an 808 circuit. Both of these assume that you'll change out what is probably a dreadful opamp.
Yep, should have been the option of 'Flick the Snot Pedal out the window and use Something else'.Rhysyrhys wrote:
Plus your poll doesn't include an other option. I say boo to that.
I've taken care of it..Rayjaysonic wrote: Sadly don't seem to be able to put it in after the event it seems. Oh well, next time!
I lelledbenecol wrote:If ever there was a pedal poll less likely to get any worthwhile responses. Sorry old thing - not beloved of shortscale, the tubescreamer.
I think by the reaction to the poll, this is the only 808 to get!!!lorez wrote:808 to me means 808 State or TB808, acid baby
I still get shivers by that machine. Add a 303 and I am all smiles stillRayjaysonic wrote:I think by the reaction to the poll, this is the only 808 to get!!!lorez wrote:808 to me means 808 State or TB808, acid baby![]()
or you don't like the associations:Mike wrote:Really not a fan of a pedal that sounds nothing like a natural amplifier overdrive.
i can understand both points of view, i feel exactly the same way about, say, strats or les pauls.Haze wrote:I put up with church buddies who ask other players about THEIR 808 tubescreamers and the "night and day" difference.