Round 4
11/13 - round four sold out. No more AF4 or PSU boards available. I do have some spare PSU kits if you bought a bare board. AF4 boards due to ship from Advanced on 12/6. All PSU parts on order or in.
10/11
Round 3 has shipped no extras available
To simplify my record keeping and try to improve accuracy, I've set up a
PayPal shopping cart for purchase of boards and kits. You can use a credit card even if you have no
PayPal account. If you don't have a credit card, email me to make arrangements.
Go to
https://mysite.verizon.net/vze3xvxs/audio/ click on "Purchase Boards and Parts". Click on the "add to cart" buttons as desired. You can increase the quantities in the cart.
Be sure to select a shipping option. In the US, most orders will fit in the Priority Mail envelope. Outside the US, I can fit 10 boards or 6 boards and a power supply kit into a small GPM envelope. Small quantities of 100 nf will fit as well. If you have more than one PSU kit, you'll need the large envelope for up to 4 psu kits. If in doubt, email me and I'll figure out shipping cost.
Pricing:
Filter Boards $5
PSU Boards $6.25
PSU Kit $28 (includes board, parts and heat sinks)
I also will offer 470 uF Panasonic FCs for the filter boards (2 required per), 100 nF/100V Epcos Film caps for decoupling, 1500 uF 35V Panasonic FCs and BC546C/BC556C.
See PSU thread for information on PSU board. Pricing will be similar to active filter board for same quantity.
PSU kit is everything needed: board and parts for 15V nominal operation including heat sinks.
BOARD DETAILS
discussion begins here (
https://www.diyaudio.com/forums/showthread.php?postid=850826#post850826)
Board silkscreen (
https://www.diyaudio.com/forums/showthread.php?postid=854766#post854766)
Schematic
https://www.delta-audio.com/Filter_DIYAUDIO/Active_filter_DIYaudio.com.sch.pdf
Spreadsheet to calculate component values
https://www.diyaudio.com/forums/showthread.php?postid=893557#post893557
Manual:
https://www.delta-audio.com/Active_Filter_Four/Active_Filter_Four_manual.pdf
Alternate download of details
https://mysite.verizon.net/vze3xvxs/audio/id20.html
Boards include:
an input buffer that can be a shelving high pass (For baffle step) and bandwidth limiting low pass
Buffered output signal taken after input buffer.
up to 4th order Hi and low pass sections in Sallen-Key equal component value topology, includes interstage buffers and attenuation to correct back to unity gain.
2 Output buffers with adjustable attenuation
2 EQ sections (peak or notch)
All pass (phase correction) section
Linkwitz transform
There are a number of interstage jumpers to allow flexibility in connection. You can use standard 0.100" headers or just a wire jumper if you are sure of your selection. This board is intended as a final board, not a prototype board, though.
one board will make a two way XO for one channel. 2 would be required for a three way up to fourth order. I think you could do a four way with 2nd order bandpass sections with 2 boards, 3 would be required for 4th order.
The board does NOT include a regulated power supply. See the Scalable PSU/regulator thread and WIKI
I will work up a manual (with help from Jens) and either modify the Excel spreadsheets to provide graphs of the resulting amplitude and phase response or provide a MathCAD
? worksheet that will be do the same. Before you groan too loudly about MathCAD
? Explorer, Jens has an idea that will make it possible to save your work as a text file that will be imported to the explorer worksheet. This will work for a filter section individually or the interaction of the basic HP and LP sections.
It would be asking far too much of Jens to make the MathCAD
? sheet cover every possible combination of HP, LP, notch filters, Linkwitz transform, shelving high pass and all pass sections. We'll leave that up to you if you need it. I've had good results looking at the driver response, figuring I need X dB of attenuation at Y Hz with a Q of Z and then treating the result as a flat driver when I look at the XO. Is the best possible simulation? No. But it is close, and you'll spend a bunch for software to do it more accurately.
There are a number of (free) circuit simulators that will allow you to model the circuit if you need to have final transfer function modeling. For instance, the free version of 5Spice has enough room to do high pass, low pass and 2 notch filters. the available drawing area is the limiting factor. Micro Cap 8 evaluation version is limited to 50 components and 100 Nodes. It should work for most applications. Please add other suggested free/low cost sims that will provide magnitude and phase response.
Round One List. All paid have shipped
Except those who requested I hold until the PSU boards ship.
| NAME | Number of boards | PAYMENT RECEIVED? | Ship Date | Received? |
| 1/137 | 10 | Y | 3/27 | Y |
| AR_sound | 4 | Y | 3/27 | Y |
| argofanatic | 20 | Y | 3/27 | Y |
| axp31 | 4 | Y | 3/27 | - |
| BobEllis | 20 | Y | 3/27 | Y |
| Brian Walter | 4 | Y | 3/27 | Y |
| cambe | 4 | n | - | - |
| capslock | 8 | Y | 3/27 | - |
| cbcassell | 4 | Y | 3/27 | Y |
| Cobra2 | 8 | Y | 3/27 | y |
| cotdt | 6 | Y | 3/27 | - |
| dabodkin | 6 | Y | 3/27 | - |
| Damon | 10 | Y | 3/27 | - |
| DaveM? | 6 | y | 3/27 | - |
| Davey | 10 | Y | 3/27 | - |
| dewardh | 4 | Y | 3/27 | - |
| dick van nierop | 2 | N | - | - |
| dp | 6 | Y | 3/27 | - |
| Ed Lafontaine | 6 | Y | 3/27 | Y |
| EdwardWest? | 4 | Y | 3/27 | - |
| EspenE? | 8 | Y | 3/27 | - |
| Garnett | 4 | Y | 3/27 | - |
| gengis | 28 | Y | 3/27 | Y |
| giulio | 4 | Y | 3/27 | - |
| gmikol | 12 | Y | 3/27 | Y |
| Harryeng | 10 | Y | 3/27 | Y |
| herm | 10 | Y | 3/27 | - |
| hipcheck | 6 | Y | 3/27 | - |
| illusionxx | 8 | Y | 3/27 | - |
| infinia | 4 | Y | 3/27 | Y |
| jacco vermeulen | 8 | Y | 3/27 | Y |
| jbateman | 2 | Y | 3/27 | - |
| JensRasmussen? | 20 | Y | 3/27 | - |
| jimbo1968 | 4 | Y | 3/27 | - |
| jimbo1968 | 20 | Y | 3/27 | - |
| JohnL? | 4 | Y | 3/27 | Y |
| JoshK? (HTG) | 6 | Y | 3/27 | - |
| joster | 10 | Y | 3/27 | - |
| JSprague | 6 | Y | 3/27 | - |
| Kendle | 4 | Y | 3/27 | - |
| Kestrel200 | 4 | Y | 3/27 | Y |
| Kro5998 | 4 | Y | 3/27 | Y |
| lm324 | 4 | N | - | - |
| mpmarino | 6 | Y | 3/27 | Y |
| Nisbeth | 12 | Y | 3/27 | - |
| Opp | 12 | Y | 3/27 | - |
| phoneisbusy | 4 | Y | - | - |
| Pinkmouse | 6 | Y | 3/27 | - |
| pool | 6 | Y | 3/27 | Y |
| rabstg | 8 | Y | 3/27 | Y |
| Ralphono | 10 | Y | 4/7 | Y |
| Ray D (HTG) | 6 | Y | 3/27 | - |
| rjb | 4 | Y | 3/27 | Y |
| saml | 6 | Y | 3/27 | Y |
| sklimek | 12 | Y | - | - |
| Spiritzly | 2 | N | - | - |
| steenoe | 4 | Y | 3/27 | Y |
| still4given | 6 | Y | 3/27 | - |
| suki | 6 | Y | 3/27 | Y |
| SvErD?? | 8 | Y | 3/27 | Y |
| t3447ml | 6 | Y | 3/27 | - |
| tg3 | 10 | Y | 3/27 | Y |
| variac | 2 | Y | 3/27 | Y |
| vgeorge | 4 | Y | - | - |
| zdaddo9 | 10 | Y | 3/27 | - |
| TOTAL | 486 | |
Round 2 signup
Buy closes 14 April. I will begin collecting money 31 March.
See (
https://www.diyaudio.com/wiki/index.php?page=PSU%2FRegulator+Boards+) for a suitable power supply. Shipping can be combined with psu boards/parts/heatsinks/transformers.
| NAME | Boards |
| UrSv? | 4 |
| Vinnie | 4 |
| SanjeevA? | 4 |
| DavidS? | 6 |
| BillH? | 4 |
| soltari_knight | 4 |
| DFDye | 4 |
| quickshift | 4 |
| RogerGustavsson | 4 |
| JamesM? | 8 |
| gmikol | 8 |
| bkin240 | 10 |
| gugi 100 | 4 |
| Hans L | 10 |
| RuudvdL? | 8 |
| rick57 | 11 |
| giannettino | 4 |
| jerishi | 4 |
| HMenke | 2 |
| bobgroger | 6 |
| jackh | 4 |
| illusionxx | 9 |
| JoeyDD? | 2 |
| MethMan? | 10 |
| PierreG? | 4 |
| agent.5 | 4 |
| BillWW? | 12 | _ | 4 |
| total | 152 |
| Name | Active filter boards | PSU boards | PSU Kits |
| Paul Ebert | 6 | _ | 2 |
| JoeyDD? | 7 | _ | _ |
| MashBill? | 2 | 2 | 2 |
| Drevland | 10 | 2 | 3 |
| Tony | 4 | _ | 2 |
| Frank | _ | 3 | 2 |
| Eric Weitzman | 4 | _ | _ |
| Ian | 10 | 6 | _ |
| dfdye | 4 | _ | _ |
| Killjoy99 | 8 | 4 | _ |
| F1 FAN | 4 | 1 | _ |
| Z33 | 3 | _ | 1 |
| Magura | 6 | _ | _ |
| Toaster | 10 | _ | 2 |
| DIAR | 4 | _ | 2 |
| rjkdivin_ | 4 | 0 | 2 |
| kevinkr | 4 | 0 | 2 |
| Kevin Graf | 6 | _ | _ |
| pixelpusher | 4 | _ | _ |
| johngalt47 | 4 | _ | 2 |
| vatofale | 2 | 1 | _ |
| jonk | 4 | _ | _ |
| RDV | 2 | 1 | _ |
| preiter | 4 | _ | _ |
| Henrik Juhl | 4 | 2 | _ |
| yggdrasil | 20 | _ | 6 |
| Scribble | 8 | 2 | 1 |
| joem | 5 | _ | 1 |
| erhana | 4 | 4 | _ |
| WillemFick? | 2 | _ | 1 |
| AR_sound | 4 | _ | _ |
| _ | _ | _ | _ |
| _ | _ | _ | _ |
| Totals | 163 | 28 | 30 |
GROUP BUY Round 2 have shipped
No extra boards are available. I might be able to do another round if there is enough interest.
The round 2 buy information has been combined with the PSU buy (
https://www.diyaudio.com/wiki/index.php?page=PSU%2FRegulator+Boards+).
