Delay Chips

Keith Hilton · Post by **Keith Hilton** » 27 Feb 2001 2:01 pm

Does anyone know some of the popular delay chips being used in effects nowdays?Company and part number if possible? I'm interested in both digital and analog chip numbers. Wonder what chip is being used in the DD3 units? Also, what delay chip was used in the Ibanez Analog Delay? These are Japanese units, but they must cross reference to our part numbers.

Scott Swartz · Post by **Scott Swartz** » 27 Feb 2001 2:18 pm

I think the only analog delay chips currently available are the Panasonic MN series. You should try asking this question here:
http://www.firebottle.org/cgi-bin/fxforums/index.cgi

There are a lot of very knowledgeable people who post here, including some actually pedal makers like Z Vex, Blackstone, Paul Perry (Frostwave).

Also, a lot of the schematics you are talking about can be found by starting here:
http://hail-eris.com/~stompbox/pedals/

Look under the "Schematics" section.

Bobby Lee · Post by **Bobby Lee** » 27 Feb 2001 3:08 pm

I've assumed that delay and other effects are done with a general purpose processor and embedded software these days. Aren't "delay chips" a thing of the past?

Jack Stoner · Post by **Jack Stoner** » 27 Feb 2001 3:41 pm

I'd think it is done with a DSP, too. Since it's digital you have to have something to control the various delay components.

Discrete components (IC's) would make the unit too big. Even the old Ibanez DM1000 delay unit that came out back in the early 80's had a processor in it.

The old analog "bucket brigade" chips are noisy and except for some retro stuff are not being used.

Jerry Roller · Post by **Jerry Roller** » 27 Feb 2001 8:11 pm

Hello Keith, does this mean we may soon have a Hilton Infra-red pedal with built in delay?
Jerry

Keith Hilton · Post by **Keith Hilton** » 27 Feb 2001 9:44 pm

Jerry, I've been doing a lot of thinking. That may not answer your question, but that's all I can say right now. Yes Jack, with Digial, you would have to have a converter. Bobby, I don't know enough about the subject to give you a logical answer at this time. I am just trying to gather some facts. I have some questions sent to Hartley Peavey. He always gets back with me, but it sometimes takes a while, as he is very busy with over 2000 employees. Scott thanks for the information on the web site. It has a lot of interesting information. [This message was edited by Keith Hilton on 27 February 2001 at 09:49 PM.]

Keith Hilton · Post by **Keith Hilton** » 1 Mar 2001 12:43 pm

Scott, the Panasonic number for the bucket brigade devices is MN3011. Everyone says the analog delay bucket brigade devices were noisy. I really don't remember them being noisy? Tell me more about the noise? Everyone suggests the best approach is to buy a finished ready to go DSP PC board for audio delay and reverb. I see problems with generic DSPs and developing my own delay and reverb algorithms. Right off you read about problems with anti-alialing filters and dithering. I suppose "dithering" could also be used to describe a guy who drink too much Vodka! Has anyone seen a finished DSP PC board for audio delay and reverb you can buy?
Scott, the links you posted were really helpful. Have you ever bought any books from AMZ or any of these other people?

Matt Farrow · Post by **Matt Farrow** » 1 Mar 2001 1:26 pm

Keith, I have a pedal with the MN series Panasonic chips, and also a pedal with the old Reticon SAD1024 analog delay chips. They can be noisy - they're after all nothing more than a bunch of capacitors capable of holding a charge for a while and then giving it up. Usually the noise in the circuit comes more from the preamp and output stages, but there is often bleed-thru into the audio of the clock signal. Nulling the clock in an analog delay is really important.

Informal poll: Do you put your delay after your vol. pedal so that when you back off you get the delay "tail" going on or do you put it before so that when you back off you get silence? Keith, if you plan to make a delay pedal combined with a vol. pedal then you might want a "pre-post" switch so that we can choose.

My signal chain: Marlen steel -> Heathkit TA28 fuzztone -> Dekley LowBoy vol. pedal -> Cort Multi-Amp (chorus, analog delay, distortion, compressor in one pedal) -> Kustom amp (with spring reverb, tremolo and vibrato.) Of course, I'm not your typical steeler

Matt Farrow

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Matt Farrow
Marlen 9-string 6+2
Kustom K150

http://surf.to/pharaohamps

Scott Swartz · Post by **Scott Swartz** » 1 Mar 2001 2:09 pm

<BLOCKQUOTE>quote:<HR>Has anyone seen a finished DSP PC board for audio delay and reverb you can buy?
<HR></BLOCKQUOTE>

I haven't, but you should try posting this question over at Ampage, maybe someone else has.

Have you ever bought any books from AMZ or any of these other people?

I have not bought the stuff from AMZ, there is a lot of good info there, but not the digital stuff you are after. In terms of books, "The Stompbox Cookbook" by Nicholas Boscorelli is really good. None of these sources will have much on DSPs, since the complexity of DSPs makes DIY diffucult. These books have a lot on distortion, EQ, tremolo, etc, stuff that 6 string guitarists are interested in.

I see problems with generic DSPs and developing my own delay and reverb algorithms. Right off you read about problems with anti-alialing filters and dithering.

You're right, there are a lot of issues to engineer in a digital circuit. For the most part, the smaller pedal makers are not pursuing this market since the upfront engineering required is so extensive and the big boys are already in the marketplace. I think if I were in your position I would try to work with peavey or someone who has already developed a workable design and buy a PC board from them. You could then build that into your pedal. I doubt you could recover the development costs if you had to start from square one. A volume pedal tailored to the steel guitar market with built in effects could have a market I guess, it sounds like that is what you are shooting for.

Blake Hawkins · Post by **Blake Hawkins** » 1 Mar 2001 7:45 pm

Volume pedal with effects? Well, folks, Sears-Roebuck sold one back in the '70's.
I still have mine. In addition to the volume function it has sound effects: "Surf"
"Hurricane", and "Wah-Wah".
The pedal itself is pretty heavy steel, so I pulled the electronics out and converted it to a straight volume pedal.
No delay function or fuzz in the original.
Blake

Keith Hilton · Post by **Keith Hilton** » 1 Mar 2001 9:28 pm

Blake, who said I was putting any kind of effect in a pedal? Blake you are giving me ideas.[This message was edited by Keith Hilton on 01 March 2001 at 09:31 PM.][This message was edited by Keith Hilton on 01 March 2001 at 09:32 PM.]

Dan Tyack · Post by **Dan Tyack** » 1 Mar 2001 10:35 pm

Lexicon has a processor that they claim is optimized for reverb and delay. I suspect that it is a general purpose processor with their algorithms in firmware.

To be honest I can't see any business in building something like this. The analog technology is pretty well understood, and there are tones of companies putting out great sounding delays for cheap prices (e.g. the Danelectro pedals, which are dirt cheap).
In terms of digital products, 99.99% of the work is in the algorithms. There are some great products for very cheap prices, especially given the design work that has gone into them. The Lexicon MPX-100 has reverb algorithms that would take a team of digital design engineers and programmers many person years to design, and it has a street price of well under $300.

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www.tyacktunes.com

Michael Brebes · Post by **Michael Brebes** » 2 Mar 2001 4:25 am

The way they got around the noise problems with the bucket-brigade chips was to use companding circuitry before and after the chips, which greatly increased their signal to noise specs. I think it was the Signetics NE570 that was the compander of choice at the time.

Keith Hilton · Post by **Keith Hilton** » 2 Mar 2001 10:39 am

Being a steel player, one thing always bothered me; Seemed to me all the electronic gear was designed for guitar players. I want to design stuff "for steel guitar", and if guitar players and fiddle players happen to like it, fine. Not that long ago only the Government and big universitys had computers.
DSP arrangements are new and only big companies have been able to afford designs in the music industry. I see DSP being as easy to work with as analog. In my opinion, one of the top companies for audio sound quality is Analog Devices. Even though Analog Devices is their name, they make DSP products. They presently make a DSP system that can be used for audio delay and reverb, and a lot more, if desired.[This message was edited by Keith Hilton on 02 March 2001 at 10:40 AM.]