freestompboxes.org

nothing much, just wanted to clip (had to retype) this before I go off to bed: that fulltone pdf archive threads starts out about the Green Rhino:

http://blueguitar.org/new/text/fulltone_thread.pdf

Daniel R. Haney wrote 3/25/1998 at Ampage forum: wrote:I may be the last to have figured this out, but...

I got to look inside a Way Huge Green Rhino pedal. It is a tube screamer design with the JFET switching removed and true bypass in its place. Parts quality is top notch, audiophile grade in many places. Has the same old 1N4148 diodes for clipping.

The emitter follower sections were TO-18 form 2N2484's (hfe=250, NPN, small signal). The op amp markings had been sanded off. (Markings?? We don't need no steenking markings!)

The Green Rhino sounds like a low-noise TS-808 with rough edges removed. At $150, it cost as much as a vintage TS-9, half of what a TS-808 does, but sounds better than both of them and is guaranteed for life. Sheesh.

I can do this, I just know I can.

The chip is a LF353N from National S.

JHS

I gotta get me some of these LF353N chippies. See what all the fuss is about

I found the original post in the ampage archive:

http://archive.ampage.org/threads/0/fxd ... air-1.html

Added the ampage archive (1996 ! - 2001) to the Links and Ressources sticky in the public stompbox folder.

Green Rhino guts confirm the chip as LF353 indeed. Also found a Screaming Llama enclosure even mentions the Tube Screamer:



Maybe a prototype for the Rhino

The NS-LF353 is very dynamic and has an extrem warm natural breakup and less mids than a 4558. A JRC 072BD is is good subtitute for the LF.

I checked LF353 from other companies (they sounded lousy, middy and muddy and w/o any dynamic response). None of them had the sound of the National Sem.

The old silver labeled MM amps use this IC too, and to me those first MM amps sound like tubeamps, the later black labeled with 072 have more of a cold transistor tone.

JHS

I just picked up a couple of the National Sem LF353.
Haven't tried them yet but, I wanted to see what all the fuss was about.

JHS wrote:The NS-LF353 is very dynamic and has an extrem warm natural breakup and less mids than a 4558. A JRC 072BD is is good subtitute for the LF.

I checked LF353 from other companies (they sounded lousy, middy and muddy and w/o any dynamic response). None of them had the sound of the National Sem.

The old silver labeled MM amps use this IC too, and to me those first MM amps sound like tubeamps, the later black labeled with 072 have more of a cold transistor tone.

JHS

Help me out here.
I do understand the way opamps handle clipped signals, based on their amplification, bandwith, slew rate etc etc.

I do not understand how an opamp influences that a TS like circuit will sound more middy, muddy or whatever. It suggests that this opamps amplification is frequency dependent (other than usual high end roll off). I find that hard to understand.

Hi Dirk
Op amps are strange things
OPA2134
LM1458
TL072
NE5532
LF442
LM833
JRC4558
LF353N
all sound different in the same circuit - use a socket and try - you WILL hear the difference.

Then try "stacking" them - my personal favourite is an OPA2134/LM1458/LM833 stack.
One disadvantage - they draw more current - so if you are using battery, it will not last as long
Cheers
bajaman

bajaman wrote:Hi Dirk
Then try "stacking" them - my personal favourite is an OPA2134/LM1458/LM833 stack.
One disadvantage - they draw more current - so if you are using battery, it will not last as long
Cheers
bajaman

Wow Baja never heard of that, only experimented stacking transistors, doesn't this influence the gain?

zj,
Check this out;

http://www.barberelectronics.com/parallelopamps.htm

Doesn't stacking them reduce the input and output impedance? I assume it would cut those numbers in half if they're the same type, and by some ratio if they are mixed types. I don't see what it does other than that.

Don't try and analyse - just try it
bajaman

Never tried stacking opamps myself but, many have said some pretty darn good things about it.

sorry to revive a dead thread but...

is the rhino an exact 808 clone (only with true bypass and chip substitution) ? I went through most of the part values from the gut shot that was posted and it really does look like an exact TS only there is one extra large electrolytic cap. Could this just be addition power supply filtering?

markm wrote:Never tried stacking opamps myself but, many have said some pretty darn good things about it.

I've done it a whole bunch and some chips stack better than others. I haven't found a great combo using a LF353 with either another op-amp or with another LF353 on top. A least in the circuits I've tried it in (clones of TS, OCD, Zendrive, a few others) the LF353 sounds better non-stacked. However, as far as stacking in general goes, I once hit on a very nice combo with one NE5532 and a TL082 on top, but that was only when that OCD clone was tweaked to be a bit darker ... when made stock, I found that I liked it best with a RC4559.

In Tubescreamers, I really like the LF353. I put one in a modded VD Sparkle Drive that now has some additional clipping options including Mosfets. The LF353 (National Semiconductor) gives it really nice tone. I had been hoarding my NS LF353 chips, but then tried a Fairchild LF353 and that was also very good. Maybe it was the circuit, maybe it was the way my ears were hearing it at the time -- the Fairchild one had a bit too much bass and not as much "hair" as the National one. But I really like this chip (LF353). I also liked a BB OPA2134 in a TS-808 clone (great with LED clippers), but currently prefer a RC4559 in it. I may yet put a National LF353 back in it, like my Sparkle Drive ... who knows. These are all good Tubescreamer chips.

disorder wrote:sorry to revive a dead thread but...

is the rhino an exact 808 clone (only with true bypass and chip substitution) ? I went through most of the part values from the gut shot that was posted and it really does look like an exact TS only there is one extra large electrolytic cap. Could this just be addition power supply filtering?

anyone?

last call! help me out!

Haha, yes, the big cap is for power filtering.

I once had one under my hands; simple tubescreamer with LF353 IC and 2N2484 transistors.

What is different in the Mk2 version?