RC4200 IC replacement for psychoacoustic bass enhancer

[DontHertzMe]

Hi all,

I'm thinking of putting together Jan Meier's psychoacoustic bass enhancer. I'm not expecting miracles , but it's likely to be a fun project.

Sadly, the RC4200 analog multiplier (and its JRC equivalent) are long obsolete. Does anyone know of a suitable replacement IC that is still manufactured?

 

[Monte McGuire]

I haven't seen that circuit, but Analog Devices makes a lot of X*Y/Z chips:

Analog Multipliers & Dividers | Analog Devices

Can you post the circuit or a reference to it?

 

[abraxalito]

If its only for DIY why would you be worried about a part being obsolete? Taobao has several sellers, prices are affordable...

 

[DontHertzMe]

I haven't seen that circuit, but Analog Devices makes a lot of X*Y/Z chips:

Can you post the circuit or a reference to it?

Here is the circuit in question, from the HeadWize archives:

If its only for DIY why would you be worried about a part being obsolete? Taobao has several sellers, prices are affordable...

Taobao, eBay, etc are only options of last resort for me alas. Shipping time to here in SA is typically 8 weeks, and things tend to go missing. Much better for me to order from places like RS and Mouser with DHL / FedEx shipping .

 

[Neil Davis]

Another option you might want to consider is using DSP. Analog Devices has a "Super Bass" algorithm in their library that should work on any of the ADAU1701 DSP boards. It's a psychoacoustic bass enhancer with three parameters. This is from the Wiki:

The inputs and outputs are stereo

SB On/Off: Activates or bypasses the algorithm

Xover Freq: Sets the frequency below which signals are considered to be in the “bass” range. These signals will be used for the bass enhancement algorithm. Higher harmonics of these signals will be generated above the crossover frequency, giving the impression of increased bass. Can be set from 20 Hz to 500 Hz.

Intensity: This controls how much gain is applied to the artificially generated higher harmonics (above the crossover frequency). This parameter can be set from 0.1 to 3.0. This value is a linear multiplier (not expressed in dB).

Bass Gain: This allows you to additionally apply a gain directly to the signal below the crossover frequency. Can be set from 0.1 to 3.0. This value is a linear multiplier (not expressed in dB).

I've tried it and it is effective without being annoying. I think the algorithm requires about 1/3 the Program Memory of the ADAU1701, so the DSP will still have plenty of resources for additional filters and other processing.

 

[abraxalito]

Taobao, eBay, etc are only options of last resort for me alas. Shipping time to here in SA is typically 8 weeks, and things tend to go missing. Much better for me to order from places like RS and Mouser with DHL / FedEx shipping .

A Taobao agent can arrange DHL shipping for you. Its fairly expensive (280rmb, $45) to SA but I believe its reliable and quick (definitely under a week).

 

[DontHertzMe]

A Taobao agent can arrange DHL shipping for you. Its fairly expensive (280rmb, $45) to SA but I believe its reliable and quick (definitely under a week).

Thanks for the info ! $45 is pretty normal, I'm accustomed to paying that.