Group Buy: Linkwitz-Riley 24db/oct xover PCB's - Page 2 - diyAudio
Go Back   Home > Forums > Commercial Sector > Group Buys

Group Buys Members group buys

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 21st February 2005, 07:40 AM   #11
AndrewT is offline AndrewT  Scotland
diyAudio Member
 
Join Date: Jul 2004
Location: Scottish Borders
Hi hornlover,
Those PCBs that you recommend. RUBBISH. The output impedance of HF channel is 25k @ -6db. All the filters are based on unity gain blocks leaving no opton to change damping or gain. Inflexible and what about his suggestion to use 4VA transformer as the PSU. Does he cater for the Fidelity market or simple Disco music via a PA system?
__________________
regards Andrew T.
  Reply With Quote
Old 22nd February 2005, 02:48 PM   #12
diyAudio Member
 
Join Date: Sep 2004
Location: Central California
ESP sells pc boards, but I dont think they have a on board power supply.
  Reply With Quote
Old 28th February 2005, 02:21 AM   #13
diyAudio Member
 
edjosh23's Avatar
 
Join Date: Oct 2004
Location: Raleigh/Atlanta
I'm designing a 2way 24db L-R XO, using ESP's design and OPA2134s. Too much stuff right now, so I've been going slow. They will be similar to ESP's so that you can make the XO any frquency you want. I'm going to try to make each board have the 2 way XO on it. The RCA will be built into the PCB so that it can mount to the outside of the chasis if liked. The two boards will be on top of eachother. So from looking at it from the back the input will be on the right, then on the left will be the low pass, then another inch over will be high pass and the right channel will be above the left.

If anyone is interested in PCBs I'd be willing to share.

Thanks,

Josh
  Reply With Quote
Old 1st March 2005, 02:52 PM   #14
AndrewT is offline AndrewT  Scotland
diyAudio Member
 
Join Date: Jul 2004
Location: Scottish Borders
Hi,
I would like a -24db/oct(4pole) bandpass board that is capable of adjustment to butterworth via EVCsallen-key and MFB filter options.
Unity gain is too inflexible.
Reasoning is to allow a bandpass to be inserted into each power amp case and selection of butterworth or LR at time of stuffing boards. MFB to allow gain selection to avoid +4.002db that ECVs-k gives when damping is .541 (if memory is correct).
If we go this route I would be looking for about 18 boards.
__________________
regards Andrew T.
  Reply With Quote
Old 1st March 2005, 03:13 PM   #15
Did it Himself
diyAudio Member
 
richie00boy's Avatar
 
Join Date: Nov 2003
Location: Gloucestershire, England, UK
I made my own boards in a modular form using unity gain. You can change the Q very easily just by changing the ratio of R1:R2 or C1:C2. I made space for 3 components for both Rs and Cs so that I can parallel them to get the desired values. If this person designs the boards in a similar way, as you are choosing a fixed Q at time of stuffing you should be fine and able to use his boards.
__________________
www.readresearch.co.uk my website for UK diy audio people - designs, PCBs, kits and more.
  Reply With Quote
Old 2nd March 2005, 04:56 PM   #16
diyAudio Member
 
Join Date: Mar 2005
Location: Central Ca.
I would like to thank AndrewT for his insightful review of our crossover. However, I would like to take this opportunity to add a few comments. The crossover board we offer is a basic two way stereo crossover withan on-board regulated power supply. It wasn't designed to be everything to everybody, but a good, basic, high fidelity crossover at a bargain price. We are proud of the quality of the board and parts we offer, using 2% polypropylene capacitors, and MIL spec Vishay/Dale 1% metal film resistors, and believe you will not find equal quality for anywhere near the price anywhere else. We could have used cheaper parts, and sound quality would probably still be excellent, but we wanted to offer a kit where people didn't feel the need to throw out half of the parts, and substitute better ones. In fact, on the full kit, we actually loose money after taking labor into consideration. You may wonder why we do this, but we do it to encourage bi-amping, which we feel is absolutely necessary for a true hi fidelity system.
It is designed as unity gain, which is fine for most applications. The bandwidth of the hi pass section is -3db at about 900kHz, more than enough for the most demanding applications. The op-amps we supply are not the latest flavor, but are excellent performers, none the less. The 553x series of op-amps are designed with audio in mind, and offer very low noise, plenty of slew rate, and are stable. We provide sockets in the kit in case anybody feels the need to experiment with other pin compatible chips. We try new chips from time to time, but until we can notice a real improvement in sound quality, we will stay with the NE5532's.
The bare board is available, for those keen on mixing and matching their favorite parts.
While the kits we offer have only 3 crossover frequencies available, any frequency can be selected by substituting the proper resistor values. The documentation we provide gives all the information needed to calculate the necessary values.
As for the transformer, although small, it still provides about 3 times the current requirements needed by the board. We could have specified a larger one, but that would just add cost with no sonic benifits. You could, of course, use a larger one, if you feel the need.
We have received many positive comments from customers about the quality and ease of construction of the crossover, and the extremely low noise levels. We feel this is very important when using systems with very high efficiencies.
I would be glad to provide AndrewT with a sample of the board, if he wishes to base his review on actual use.

A fellow music lover
Ron Shaw
H.E.L.
  Reply With Quote
Old 4th March 2005, 06:22 AM   #17
AndrewT is offline AndrewT  Scotland
diyAudio Member
 
Join Date: Jul 2004
Location: Scottish Borders
Hi Ron Shaw,
Thanks for that comprehensive reply particularly the ref to component quality.
My language was a bit strong but I stand by my strongly held view and the comment. Inflexible. Sure glad I went on to explain my reasoning.
Re post 15, Richie00boy the changes to cap ratios are rarely documented (can you refer me to a site that provides a calculation method) to achieve desired Q. Once these odd ratios are found you then have to // expensive tight tolerance caps to achieve very odd values. Then what happens if you want a new frequency? Oh just put all the resistors into sockets so they can be changed instead, I think not!
__________________
regards Andrew T.
  Reply With Quote
Old 4th March 2005, 08:09 AM   #18
Did it Himself
diyAudio Member
 
richie00boy's Avatar
 
Join Date: Nov 2003
Location: Gloucestershire, England, UK
Having finally seen the schematic for Ron Shaw's board I have to say I can't really fault it with the exception of the 100k pot to attenuate HF, it needs a buffer after it. My only other gripe is that the capacitor symbols used are what I know as polarised electrolytics, which is obviously not what would be used given the small values, but still...

AndrewT, I don't have the formulas to hand, but I can offer you a very simple C++ program I wrote a long time ago to do the calculations for you. Check out the High Pass Filter Designer and Low Pass Filter Designer programs on my utilities page.

I do not have a problem with paralleling components and use standard 5% tolerance caps with no problems, and always arrive very close to the value I want. I will add that when I design an active crossover I tend to get the design pretty close first time (by spending time on the measurement and design) so the need to change frequency is minimal
__________________
www.readresearch.co.uk my website for UK diy audio people - designs, PCBs, kits and more.
  Reply With Quote
Old 8th March 2005, 08:26 PM   #19
diyAudio Member
 
Join Date: Mar 2005
Location: Central Ca.
We decided not to add another buffer section to the output in order to minimize stages, since its a good possibility that the following stage will be buffered anyway. We have not had anyone have an issue with the input impedence of the stage following the hi-pass section, so so far, we will leave it like it is.
The cap sysmbols are IEC recognized, as are the symbols using straight lines for both sides. Polarized caps are shown with a (+) marking the positive plate. We dont use the symbol using both straight lines because that symbol is also an IEC accepted symbol for contacts, such as you may find in a circuit breaker. Sorry for any confusion this may have caused.

Ron Shaw
H.E.L.
  Reply With Quote
Old 8th March 2005, 08:47 PM   #20
jleaman is offline jleaman  Belgium
Banned
 
Join Date: Apr 2002
Send a message via AIM to jleaman
Can we see a board Layout. ?
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Linkwitz-Riley Crossover questions MBrej Solid State 2 15th January 2009 12:19 PM
A Challenge to Linkwitz-Riley ? jackinnj Multi-Way 17 14th March 2006 11:50 PM
Linkwitz-Riley Cross over question rs1026 Chip Amps 2 27th August 2004 09:15 PM
linkwitz-riley crossover arthur Solid State 0 28th April 2003 10:26 AM
Linkwitz-Riley 24dB/octave Phase Coherent Crossover djdan Solid State 30 25th September 2002 10:32 PM


New To Site? Need Help?

All times are GMT. The time now is 06:53 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2