SHEcho and PT80 idea

[Roobin]

I've just had a look at the SHEcho at GGG, and it looks cool. However, I once read somewhere that the HT8955A chip isn't that good. Could someone please clarify? Also, how does using the DRAM work? Could delay times be increased by increasing DRAM size, or is that nonsense?

Also, I was thinking about the PT80. If you've got the normal signal and the delayed signal at the out put, could you not just split them, and feed the delayed signal into another delay circuit? Or would there be some comprimise with quality? (I'm sorry, I don't really know much about this delay stuff! ).

Anyone thinking of having a pop at the SHEcho?

[geertjacobs]

Previous topic about adding a Direct Out to a PT-80

The PT-80 has been discussed here quite a bit.
Maybe some of your questions are answered when you do a search on PT-80.
A very nice DIY delay.

Caution: delays can be expensive to build. In other topics commercial delay pedals are recommended as very cost effective (Echo Park etc...)

[Mark Hammer]

The PT2399 uses a higher resolution conversion (10-bit) but more importantly uses delta-modulation where the *change* in signal is what is coded, not the absolute level.  This results in a higher resolution/quality sampling in the PT2399 than in the HT8955.  The HT8955 isn't THAT bad when decent filtering is used (same quality as the original Soundblaster cards), but if you are aiming for more clarity with greater bandwidth, the Princeton chips are a better investment.

Unfortunately, the memory limits are set by the number of address lines the chip supports.  It is not possible to extend the number of address lines beyond the 256k of RAM space the HT8955 accesses/addresses.  In the case of the PT2399 the RAM is internal to the chip tself, hence VERY fixed.

[Roobin]

Thank you very much, looks interesting, esp the idea about dropping the levels down to nil.

Caution: delays can be expensive to build. In other topics commercial delay pedals are recommended as very cost effective (Echo Park etc...)

Yeah, i was looking at the echo park, marshall echohead and DD6. As a floyd fan, I like the idea of the SHEcho extending to 800ms,.

Hmm, interesting points there Mark. I see now that the address lines set the max delay effectively, and so getting higher memory does nothing.

[Mark Hammer]

The SHEcho may well sound reasonably good.  I built Dean's first design, which lacked all the companding and filtering of his recent redesign, but it still sounded respectable if you paid attention to levels and weren't expecting Lexicon or TC quality on a dime.

The Marshall unit is nicely priced and is a real meat and potatoes delay with lotsa time for looping.

As far as bang for the buck goes, the Echo Park does a LOT of tricks for the money.  The stereo options are woefully underestimated by buyers.  It also does some chorus sounds as well as Slow-Gear type sounds.  The 3 filter modes are also very useful as is the trails function.