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DIY Stompboxes => Building your own stompbox => Topic started by: Yuan Han on March 24, 2004, 07:04:40 AM

Title: Holtek 8970 echo
Post by: Yuan Han on March 24, 2004, 07:04:40 AM
Heyo,

I was emailing this local guy who brings in Belling BBDs to ask about them, and he was recommending that I should use HT8970.

http://www.holtek.com.tw/docum/consumer/8970.htm

It looks exactly like princeton pt2399 eh ?

Anyone tried it ?

YH
Title: Holtek 8970 echo
Post by: Mark Hammer on March 24, 2004, 10:42:53 AM
There is a certain conspicuous similarity between some Holtek chips and some Princeton chips, although the pinouts are different.  Combine that with the fact that they have pretty much been discontinued by Holtek, and I wouldn't be surprised if Holtek sold the dies to Princeton or something like that.

I've made a delay with the HT8955 (and an outboard 256k RAM chip), using Dean Hazelwanter's board layout, and it works fine, although like Scott Swartz's PT2399-based delay, it could probably benefit from companding and better filtering to keep noise out.

We've had lengthy discussions about it recently, but my own opinion is that once you stick on all the accoutrements of your average analog delay line (compander, lowpass filtering), there isn't a whole lot of audible tonal difference to be had between 10-bit digital chips like the HT8970/55 or PT2395/96/99 and BBDs, especially once it hits your amp and comes out the speakers.  I'm probably not the majority, but I know I'm not alone.  I'll let "gentleman Ed" persuade you to go the Beiling route.
Title: Holtek 8970 echo
Post by: Paul Perry (Frostwave) on March 24, 2004, 08:18:27 PM
Yuan, it that chap bringing in any other Belling products? They make a lot of switches for 'famous name'  US amp manufacturers, also spring reverb units, PCB mount sockets etc.
Title: Holtek 8970 echo
Post by: Yuan Han on March 25, 2004, 07:58:49 AM
mmm guess it boils down to the usual digital analog thingie...

Paul: *that* i didn't know. last email i had from them was their engineer tell me that HT8970 is much better than BBDs, and BBDs are only for replacement. I would drop an email to them about spring reverbs and amp parts. I don't think they actually bring them (belling prods) to singapore all the time though.but that was an enlightening fact :) thanksy

yh