Hot Rodding an Ashly X-Over

[docaudio]

I've been working on cleaning up an older Ashley XR2001 crossover that I use for my mains to divert everything below 60Hz to the Sub. I've attached a schematic and have swapped out the opamps for LM4562s.
I also had to change the voltage regulators to + 15v.
Here are some initial observations:
Things are much quieter than before, but I'm getting a bit of 'rocky-spity' noise. Someone is not happy.
Also, the sound is a bit brittle. I'd really like to either remove or at least improve the coupling caps (c20,40,45,50,73,76,77)
Any other suggestions would by greatly appreciated.
I know there are probably better choices for opamps, but they were available.
Thanks,
Bill

 

[docaudio]

Correction...

The TL072s listed on the schematic are actually 4560s...
The 2043s are correct.
-Bill

 

[docaudio]

Bump..
Should this get moved to Analog?

 

[econofi]

Did you ever get more suggestions about this? I have an Ashly XR2001, too. While I love the ease of use and versatility, it is a tad noisy and the deep bass drive is not that great. I suspect the 20Hz high-pass is the culprit, but it could be power supply or caps. I'd like to lower the effective output to 10Hz or even 5Hz if the system stays stable.

Also, although I doubt I could hear it, all those potentiometers have to subtract something. Stepped attenuators instead?

This is such a well-built and well-conceived device at such a bargain price, there should be lots of mods for it. Maybe everyone went digital, but I'm not ready yet.

Paul

 

[psemeraro]

Get rid of all the electro DC blocking caps, yuk! If you must have dc free output then keep the last ones in the chain (c77 etc.) but replace with something better like this:The Madisound Speaker Store

I've done a rebuild of several Rane xovers - opamps, removed dc caps, nude vishay resistors, etc. They went from sounding terrible to sounding quite good. Not exactly transparent but definitely usable in a good system.

 

[djoffe]

Here are some initial observations:
Things are much quieter than before, but I'm getting a bit of 'rocky-spity' noise. Someone is not happy.
Also, the sound is a bit brittle. I'd really like to either remove or at least improve the coupling caps (c20,40,45,50,73,76,77)

It's quite likely that there are supersonic oscillations (e.g. many MHz) with the new LM4562 opamps. Although unity gain stable, they list the GBW at 55 MHz.
TL072 GBW (original opamps) was 3 MHz.

That large difference says that the power supply bypass caps (if there even are any, as the schematic doesn't show power pins) may be too few and too far away from the pins to do their job. The LM4562 needs 0.1 uF or 0.01 uF bypasses quite close to the power and gnd pins to remain stable at high frequencies.

If the sound is still funny, get a good scope and probe around looking for high frequency oscillation.

Update My Dynaco

Akitika GT-101 Audio Power Amplifier Kit

 

[Gibbi]

I picked up the XR2001 and like it alot. but of course want to make it better. Any updates on this thread??

I am not electronically educated but can replace parts and am looking for guidance on what exactly (specific for sure) opamps and caps I can replace or remove to improve the sound. I plan to install opamp receptacles so I can plug and play.

 

[Gibbi]

BTW, one of my favorite opamps is the LT1364 and I would like to try these in the XR2001 if there is a chance they will work. I've popped them in several DAC's and preamps and have yet to have them not work and sound better than OPA2134, LM4562, and others.

 

[Gibbi]

As an update on this thread I did replace the opamps as stated above, eliminated all coupling caps save 1, and recapped the remainder of the electrolytics. Sound is greatly improved from stock.