TLC2272 vs. TLC2262

[Stompin Tom]

Is there much difference between these? I've searched the archives and looked at the data sheets, and I don't think there's much, but I'm not very knowledgable about these sorts of things and I wanted to make sure.

Basically, I was thinking of making ROG's tonemender (http://www.runoffgroove.com/tonemender.html) as a basic sort of preamp for a power amp. They recommend the tlc2272 over the readily available tl072... So I'd rather go that route, and I see small bear has 2262s... any problems with the sub? advantages or disadvantages?

[Ardric]

From the data sheets it seems like the 2262 is a slower, low-power version, like an improved tl062.  The 2272 is the more power hungry, low-noise version, like the tl072.

The Tonemender circuit doesn't look very demanding.  The first opamp is a unity buffer into the tone stack, which, lifted mostly from guitar amps, is very high impedence.  Driving it harder with a beefy opamp is pointless unless the whole thing was scaled down (smaller resisters and pots, larger caps).  Going all out like that would probably make it a little lower noise in practice, but at the cost of shorter battery life.

The tonestack will eat a lot of volume.  The second opamp amplifies the signal to recover that, and drives the output jack.  It's set up for a maximum gain of about 100x, so I guess at really high gain settings the low-power opamps may have treble problems.  This should only happen when you turn all the tonestack knobs down really low, then crank up the gain control to get unity volume back.  If you socket it you could try all the usual chips and see what you like best.

[Stompin Tom]

Thanks! I figured there'd be some performance differences, I just wasn't sure. I guess It'd be worth hunting down a 2272 to compare for myself.

[Stompin Tom]

Ok, here's a question I feel stupid asking... I'm looking at mouser (http://www.mouser.com/search/refine.aspx?Ntt=tlc2272) and the 2272s all have letters after them... what do they all mean? Which do I want?

[johngreene]

Ok, here's a question I feel stupid asking... I'm looking at mouser (http://www.mouser.com/search/refine.aspx?Ntt=tlc2272) and the 2272s all have letters after them... what do they all mean? Which do I want?

just check the data sheet:
http://focus.ti.com/lit/ds/symlink/tlc2272.pdf
CD = commercial temp range, surface mount SO package
ACD = lower noise version of CD
ID = industrial temp range, SO package
IAD = low noise industrial
MD = military temp range, SO package
AMD = low noise military

So, if I drop the noise 'A' and temp 'C, I, M' letters:

D = SOIC package
FK = Ceramic LLC
JG = Ceramic DIP
P = Plastic DIP (probably the one you want)
U = Ceramic Flat Pack

--john

[Stompin Tom]

Thank you. I thought I did look for that info on the data sheet. Clearly I didn't know what I was looking at. Now I do!