Crossover op-amps
 

I've been playing with this active crossover

http://sound.westhost.com/project09.htm

and have used TL072 which I have lots of. But wondered what would be
better - without paying a fortune?

--
*Be more or less specific *

Dave Plowman London SW
To e-mail, change noise into sound.

Crossover op-amps
 

Dave Plowman (News) wrote:

I've been playing with this active crossover

http://sound.westhost.com/project09.htm

No workee it seems ...

and have used TL072 which I have lots of. But wondered what would be
better - without paying a fortune?

whatever 5532, OPA 275, BB 2134 come to mind, OPA 275 or 176, if applicable,
are very well behaved turn-on and -off wise, nice if you have a power
outage. Remember a 100 Ohm series resistor on the output.

Do not run your power amps flat out, attenuating 15 dB makes a lot of sense
and greatly reduces the risk of mishaps.

5532's surprised me in a listening test I was a part of but are perhaps "too
forward". OPA275 are perhaps a wee bit laid back. My favourites are OPA176
or the also "up front" 2134.

Most circuits I can imagine have two amplification stages, using different
opamps may sound better than twice the same.

Using a digital controller has interesting properties: steeper x-over
possible, adjustable eq for troublesome midrange-units and DA conversion
after x-over.

Feel free to disagree, those who think there is no difference should buy the
cheapest that sounds no different from the best to them. There are vastly
costlier alternatives out there.

Kind regards

Peter Larsen

Crossover op-amps
 

In article ,
Peter Larsen wrote:
Dave Plowman (News) wrote:

I've been playing with this active crossover

http://sound.westhost.com/project09.htm

No workee it seems ...

Ah - it's not, is it? Was working earlier on today.

and have used TL072 which I have lots of. But wondered what would be
better - without paying a fortune?

whatever 5532, OPA 275, BB 2134 come to mind, OPA 275 or 176, if
applicable, are very well behaved turn-on and -off wise, nice if you
have a power outage. Remember a 100 Ohm series resistor on the output.

Right. For a direct replacement in the PCB they'd have to be 5533 or
another dual op-amp. I've incorporated a mute relay before the power amps.
100 ohm resistor present

Do not run your power amps flat out, attenuating 15 dB makes a lot of
sense and greatly reduces the risk of mishaps.

Right.

5532's surprised me in a listening test I was a part of but are perhaps
"too forward". OPA275 are perhaps a wee bit laid back. My favourites
are OPA176 or the also "up front" 2134.

Right again. I'll get some prices.

Most circuits I can imagine have two amplification stages, using
different opamps may sound better than twice the same.

Pity the site is down. There is an input stage, two stages each for high
and low pass, four for mid, and an output driver for each. But non doing
anything terribly taxing for any op-amp. The input has the choice of
balanced - and I'd guess could be improved upon.

Using a digital controller has interesting properties: steeper x-over
possible, adjustable eq for troublesome midrange-units and DA conversion
after x-over.

I've enough problems with analogue. ;-)

Feel free to disagree, those who think there is no difference should buy
the cheapest that sounds no different from the best to them. There are
vastly costlier alternatives out there.

Kind regards

Peter Larsen

--
*If one synchronized swimmer drowns, do the rest have to drown too?

Dave Plowman London SW
To e-mail, change noise into sound.

Crossover op-amps
 

"Dave Plowman (News)" wrote in message
...
I've been playing with this active crossover

http://sound.westhost.com/project09.htm

and have used TL072 which I have lots of. But wondered what
would be
better - without paying a fortune?



Take care with the circuit design particularly biasing resistors.
The TL072 is a bi-fet op-amp and thus relatively high input
impdenece which some designer may have tried to use.


--
Woody

harrogate three at ntlworld dot com

Crossover op-amps
 

On 6/11/2013 12:37 AM, Dave Plowman (News) wrote:
I've been playing with this active crossover

http://sound.westhost.com/project09.htm

and have used TL072 which I have lots of. But wondered what would be
better - without paying a fortune?


**I'm rather partial to the AD825. Modestly priced and very high
performance. You'll need to consider surface mount techniques though.
Not available in DIP. Brown Dog have suitable adapters.

--
Trevor Wilson www.rageaudio.com.au

Crossover op-amps
 

Re-read the OP. You're talking about active crossovers so
probably running at relatively high levels. IME you would be
probably spending money unneccessarily - the TL072 is quite good
at higher levels.

I once built a set of line amps for my Quad33 using TL074s taking
the tone controls out in the process. I ended up with amps that
were frequency flat within +/-0.1dB from 14Hz to 240KHz and had a
worst case phase error of about 15degrees at around 12Hz back to
0 degrees before 30Hz. They were noticably 'cleaner' than the
original discrete amps.

Later I built the pre-amp board with the same ICs and it too
sounded good. I later replaced the TL074's with LM837sand could
not tell any difference.

The source was either CD or LP with AT90E(?) m/c cartridge
feeding the Quad, thence a home built dual mono power Mosfet amp
using amp boards from Ambit (remember them?) and a regulated
supply designed by the great JLH, into a pair of transmission
line speakers to the Dr Bailey design from WW 1972 (oh how I
loved those speakers.) In an 18x12ft lounge I could rattle the
windows with the pedal reeds from the organ of Limburg
Cathedral - pity that disc went walkies.

Them were't days................


--
Woody

harrogate three at ntlworld dot com

Crossover op-amps
 

On 05/11/2013 20:09, Woody wrote:
snip

The source was either CD or LP with AT90E(?) m/c cartridge
feeding the Quad, thence a home built dual mono power Mosfet amp
using amp boards from Ambit (remember them?) and a regulated
supply designed by the great JLH, into a pair of transmission
line speakers to the Dr Bailey design from WW 1972 (oh how I
loved those speakers.) In an 18x12ft lounge I could rattle the
windows with the pedal reeds from the organ of Limburg
Cathedral - pity that disc went walkies.

Them were't days................


Do you happen to have the speaker design?
--
Cheers, Rob

Crossover op-amps
 

On 06/11/2013 08:37, RJH wrote:
On 05/11/2013 20:09, Woody wrote:
snip

The source was either CD or LP with AT90E(?) m/c cartridge
feeding the Quad, thence a home built dual mono power Mosfet amp
using amp boards from Ambit (remember them?) and a regulated
supply designed by the great JLH, into a pair of transmission
line speakers to the Dr Bailey design from WW 1972 (oh how I
loved those speakers.) In an 18x12ft lounge I could rattle the
windows with the pedal reeds from the organ of Limburg
Cathedral - pity that disc went walkies.

Them were't days................


Do you happen to have the speaker design?

I've got the Bailey Wireless World articles and the CJ Rogers design,
which is more elegant imho. The latter is also available somewhere
on the internet...

--
Eiron.

Crossover op-amps
 

In article , Dave Plowman (News)
wrote:
I've been playing with this active crossover

http://sound.westhost.com/project09.htm

and have used TL072 which I have lots of. But wondered what would be
better - without paying a fortune?

Personally, I'm usually happy enough to use something from the TL07x or
5532/4/etc families. Although I still would tend to turn to the more
obscure HA12017 if I want good performance with a large voltage swing.
Despite being made as RIAA amps then work nicely in other applications
provided you take care with the compensation, etc.

JIm

--
Please use the address on the audiomisc page if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html

Crossover op-amps
 

In article ,
Dave Plowman (News) wrote:


http://sound.westhost.com/project09.htm

is working today.

--
*Ham and Eggs: Just a day's work for a chicken, but a lifetime commitment

Dave Plowman London SW
To e-mail, change noise into sound.