Are the test results useful? Should I continue to provide more data? Are people waiting for opamp tests before ordering? 😕 Please let me know.
Hi Tyler,
Personally I'm going to make my own tests when I get the boards. But I'm not sure that everybody will/can, and therefor I hope you will keep on posting results for us to study.
Thanks for your hard work
\Jens
Personally I'm going to make my own tests when I get the boards. But I'm not sure that everybody will/can, and therefor I hope you will keep on posting results for us to study.
Thanks for your hard work
\Jens
Hello all,
I can understand from Tyler, that not everybody that initially signed up at the WIKI has paid yet. Why is that? – Is it because of missing information or did you simply change your minds. Tyler has put in a lot of work getting this thing together, so I think it’s a bid sad that the people that signed up didn’t take the time to cancel their initial order. This could have put Tyler in a bit of a difficult position since the setup and tool fee is far from cheap. So come on the last of you. Stand by you word – or maybe it will be more difficult to get a group order together when you REALLY are interested a project.
I hope I’m not out of line here.
\Jens
I can understand from Tyler, that not everybody that initially signed up at the WIKI has paid yet. Why is that? – Is it because of missing information or did you simply change your minds. Tyler has put in a lot of work getting this thing together, so I think it’s a bid sad that the people that signed up didn’t take the time to cancel their initial order. This could have put Tyler in a bit of a difficult position since the setup and tool fee is far from cheap. So come on the last of you. Stand by you word – or maybe it will be more difficult to get a group order together when you REALLY are interested a project.
I hope I’m not out of line here.
\Jens
Maybe some just didn't look in the thread for a while (PM/email?)
Btw I have to compliment Tyler for the way he handles the groupbuy. Good info, clear ordering webpage. Thanks for all your effort so far 😉
Hope the groupbuy works out well
Btw I have to compliment Tyler for the way he handles the groupbuy. Good info, clear ordering webpage. Thanks for all your effort so far 😉
Hope the groupbuy works out well
2SK389 US source
Hello, I've found a US source for the dual fet 2sk389 (BL) used in the opamp modules: www.slelectronics.net
They carry it at 1.8 US$/pc... 😀 if it wasn't for the outrageous shipping costs to Italy (24,5 $)..... 😡
They have 25 on stock but told me that can order more.
Tiroth, in case you change your supplier to this one I want a discount 😉
Cheers
Andrea
Hello, I've found a US source for the dual fet 2sk389 (BL) used in the opamp modules: www.slelectronics.net
They carry it at 1.8 US$/pc... 😀 if it wasn't for the outrageous shipping costs to Italy (24,5 $)..... 😡
They have 25 on stock but told me that can order more.
Tiroth, in case you change your supplier to this one I want a discount 😉
Cheers
Andrea
Thank you Andrea! I will give them a call. I have already recieved the first 100 2SK389 from MCM @ $2.15 but I will probably need at least 100 more to fill all orders, so it is worth looking into. I was initially concerned that with the size of the order (>800 opamp boards at one point) that others buying independently might buy up all of the North American stock, as happened with Brian's resistor order. Doesn't seem to be happening though.
The shipping is certainly ridiculous, you could easily fit any number in a global priority envelope. Unless you package them as MCM did, one 2SK389 per bag.
The package was as big as a football!
The shipping is certainly ridiculous, you could easily fit any number in a global priority envelope. Unless you package them as MCM did, one 2SK389 per bag.
The package was as big as a football!
Tiroth,
you could send an e-mail reminder to those who signed up on the wiki but didn't order. You took the initiative, did the work (for free), and took the financial risk. Most ppl wouldn't make it to a single of these criteria 😉
Of course there is no recourse if someone changed his mind, but a reminder is fair in this case.
Note also for all those not familiar with Paypal: you can pay Paypal by credit card if you're not a member.
you could send an e-mail reminder to those who signed up on the wiki but didn't order. You took the initiative, did the work (for free), and took the financial risk. Most ppl wouldn't make it to a single of these criteria 😉
Of course there is no recourse if someone changed his mind, but a reminder is fair in this case.
Note also for all those not familiar with Paypal: you can pay Paypal by credit card if you're not a member.
Help
I can not spend too much time to understand the combo right now, so please kindly give me a definite number so that I can order and make payment for this group buy.
What I want is a stereo 3rd/4th order 3 way active crossover to replace my CX3400. Would go with discrete opamp later in the futher. Will use ready made opamp chip at the beginning. So how many main boards I need and how many opamp boards do I need to order now?
Thanks in advance,
Chris
I can not spend too much time to understand the combo right now, so please kindly give me a definite number so that I can order and make payment for this group buy.
What I want is a stereo 3rd/4th order 3 way active crossover to replace my CX3400. Would go with discrete opamp later in the futher. Will use ready made opamp chip at the beginning. So how many main boards I need and how many opamp boards do I need to order now?
Thanks in advance,
Chris
Chris,
The simplest answer would be that you need eight mox boards for stereo. This gives you up to 4th order on LP, HP, and BP.
As for the number of opamps, you need only one input buffer and two output buffers per side, so six sets of opamp boards is more than enough. If you don't want to use the discrete boards then you don't need to order any, but if I understand you correctly you want them on hand for future use.
I know it is confusing, but the number of options is the downside to the flexibility the design offers.
The simplest answer would be that you need eight mox boards for stereo. This gives you up to 4th order on LP, HP, and BP.
As for the number of opamps, you need only one input buffer and two output buffers per side, so six sets of opamp boards is more than enough. If you don't want to use the discrete boards then you don't need to order any, but if I understand you correctly you want them on hand for future use.
I know it is confusing, but the number of options is the downside to the flexibility the design offers.
It is no longer necessary to update the wiki, please make your actual payments now.
There are a few people who have updated the wiki this week but haven't ordered. I need your actual payment by this Saturday night if you want to participate.
http://www.anidian.com/audio/construct/mox_order.shtml
I would like to have all payments made by midnight Saturday, May 8th.
MBK alerted me that there may be some odd delays with PayPal and orders from outside the U.S. I have not been able to confirm that, but if you sent in your order before today and are on the list below, please email me.
Payments not received:
bg40403
Blitz
Chris Ma
cowanrg
diamdiam
dqswim
feppe
grataku
jhead
JoeM
jonk
kestrel200
leadbelly
McKajVah
motherone
mwmkravchenko
Peter Daniel
RKH
roibm
steely3
steve
Before you worry
Ed, Paolo, Axel: I have received your orders but couldn't match them up with a nick and/or order quantity in the wiki. So don't worry if I mistakenly listed you above.
Mr. Lee: I refunded your payment, so please resubmit your order prior to Saturday
If you just paid this morning, I wouldn't be alarmed if you show up in the list above, but feel free to send me an email. I will reply to all inquiries this evening due to network issues at work.
Everyone else, I have your payment. Thanks again.
There are a few people who have updated the wiki this week but haven't ordered. I need your actual payment by this Saturday night if you want to participate.
http://www.anidian.com/audio/construct/mox_order.shtml
I would like to have all payments made by midnight Saturday, May 8th.
MBK alerted me that there may be some odd delays with PayPal and orders from outside the U.S. I have not been able to confirm that, but if you sent in your order before today and are on the list below, please email me.
Payments not received:
bg40403
Blitz
Chris Ma
cowanrg
diamdiam
dqswim
feppe
grataku
jhead
JoeM
jonk
kestrel200
leadbelly
McKajVah
motherone
mwmkravchenko
Peter Daniel
RKH
roibm
steely3
steve
Before you worry
Ed, Paolo, Axel: I have received your orders but couldn't match them up with a nick and/or order quantity in the wiki. So don't worry if I mistakenly listed you above.
Mr. Lee: I refunded your payment, so please resubmit your order prior to Saturday
If you just paid this morning, I wouldn't be alarmed if you show up in the list above, but feel free to send me an email. I will reply to all inquiries this evening due to network issues at work.
Everyone else, I have your payment. Thanks again.
🙂 Sorry Ed, I know we corresponded but due to the latest virus I can't check my email while at work. 🙁
Tiroth,
"Are the test results useful? Should I continue to provide more data? Are people waiting for opamp tests before ordering? Please let me know."
Test results are always good to see, how about a plot of a band pass filter.
Any progress on the new parts list. What kind of sockets did you try. How about a close up of the discrete opamp off the Mox board showing the connection pins. Any measurements of output offset. Last, I think it would be a good just to show the response of the discrete opamp by itself configured as a buffer. Maybe more information will help encourage people along.
BDP
"Are the test results useful? Should I continue to provide more data? Are people waiting for opamp tests before ordering? Please let me know."
Test results are always good to see, how about a plot of a band pass filter.
Any progress on the new parts list. What kind of sockets did you try. How about a close up of the discrete opamp off the Mox board showing the connection pins. Any measurements of output offset. Last, I think it would be a good just to show the response of the discrete opamp by itself configured as a buffer. Maybe more information will help encourage people along.
BDP
Trioth,
I'm sorry my friend but I'm still confused about what all I would need to build a stereo set of active crossovers with say x points at 300 and 3000. I understand the number of boards now but not the number of components, i.e. opamps, etc. I'd need. I really want to b-iamp some speakers using Brian's Gainclone kits but not sure how'd I'd go about doing it with your kit. I think that there might be others who have the same reluctance. Unfortunately I'm fairly new to all this still and I don't have an EE so things are not as obvious to me as to Brian and some others.
I'm sorry my friend but I'm still confused about what all I would need to build a stereo set of active crossovers with say x points at 300 and 3000. I understand the number of boards now but not the number of components, i.e. opamps, etc. I'd need. I really want to b-iamp some speakers using Brian's Gainclone kits but not sure how'd I'd go about doing it with your kit. I think that there might be others who have the same reluctance. Unfortunately I'm fairly new to all this still and I don't have an EE so things are not as obvious to me as to Brian and some others.
Guys, it's me who am confused now. So many people signed up and now, much later, keep on asking how the thing actually works. This is DIY after all. Some assembly required. Some thinking required. In fact even if it came pre-assembled, you'd still need to know how it works. Chances are you'd need to read the instructions as well.
Download the schematics from Jens' pages. Make a block diagram of what you want to achieve, for instance:
in->buffer->HP 12 dB/oct->buffer->out hi;
aux in (no buffer needed->LP 12 dB/oct->buffer->out low
Then count the op amps:
- each time you want a buffer (input or output), count 1 opamp
- each time you want a filter section of 6 or 12 dB/oct, count 1 op amp
-if you want to build a balanced output buffer, you better know by yourself how many op amps that needs. Hint: can be done with 2 or 3, or with an IC like DRV134
- multiply by 2 (two) for stereo
For my example above, a stereo config for a 2-way with no more than 2nd order filters, and unbalanced outputs, you need 1 input buffer, 2 output buffers, 2 filter buffers, stereo x2 = 10 op amps. 8 op amps fit in one set. So, order 2 sets and you'll have 6 op amps leftover to play.
Look at it this way. Order some op amp boards in excess of what you need. The boards are a bargain. The price of *one* op amp board with 8 op amps on it is less than the price of a *single decent IC dual op amp*. You can order your JFET's later if you're unsure, because the premium ones are rather pricey. You can order 4 op amp sets of 8 each and let them sit for a year, using a dollar a piece IC's for the X-O, and build the discrete op amps little by little over time.
Same for the MOX boards, come on, one PCB for 6 dollars, fully flexible and expandable. It doesn't get any cheaper. Order some more than you need, you get almost 2 additional boards just for the price of the shipping.
I don't think you'll get a fully flexible x-o anywhere else soon, and certainly not at that price point.
Tiroth, you've been too honest. You should have added a 30% buffer in the price to account for your risk. No one would have noticed anyway, since no one notices how cheaply you are selling them.
Download the schematics from Jens' pages. Make a block diagram of what you want to achieve, for instance:
in->buffer->HP 12 dB/oct->buffer->out hi;
aux in (no buffer needed->LP 12 dB/oct->buffer->out low
Then count the op amps:
- each time you want a buffer (input or output), count 1 opamp
- each time you want a filter section of 6 or 12 dB/oct, count 1 op amp
-if you want to build a balanced output buffer, you better know by yourself how many op amps that needs. Hint: can be done with 2 or 3, or with an IC like DRV134
- multiply by 2 (two) for stereo
For my example above, a stereo config for a 2-way with no more than 2nd order filters, and unbalanced outputs, you need 1 input buffer, 2 output buffers, 2 filter buffers, stereo x2 = 10 op amps. 8 op amps fit in one set. So, order 2 sets and you'll have 6 op amps leftover to play.
Look at it this way. Order some op amp boards in excess of what you need. The boards are a bargain. The price of *one* op amp board with 8 op amps on it is less than the price of a *single decent IC dual op amp*. You can order your JFET's later if you're unsure, because the premium ones are rather pricey. You can order 4 op amp sets of 8 each and let them sit for a year, using a dollar a piece IC's for the X-O, and build the discrete op amps little by little over time.
Same for the MOX boards, come on, one PCB for 6 dollars, fully flexible and expandable. It doesn't get any cheaper. Order some more than you need, you get almost 2 additional boards just for the price of the shipping.
I don't think you'll get a fully flexible x-o anywhere else soon, and certainly not at that price point.
Tiroth, you've been too honest. You should have added a 30% buffer in the price to account for your risk. No one would have noticed anyway, since no one notices how cheaply you are selling them.
the price cant be beat for sure. however, i think the concerns have come from rather simple understandings of active crossovers.
this is DIY, and that is assumed. however, because of the pricepoint, and the general attractiveness of this offer, many who were previously unaware of the functionality of active crossovers have become interested. this thread has been technical to say the least.
for somene who is unaware of how an active crossover works, its VERY confusing. simply saying you need a HP filter with a few buffers, etc... gets confusing. i know that for my maggies, i needed a simple 2-way 2nd order crossover. but i was initially unaware as to what a buffer was, why i needed one, and am still a bit uncertain of why 1 input and 2 output buffers are needed.
just keep in mind that we al have to learn somehow. questions will arise. and of couse, the most common question will be "for my situation, what is needed". and until your post just now, it hasnt been 100% clear for most people.
but now there should be little excuse for not knowing at least WHAT you need. how to impliment could be another issue though 🙂
(btw, i am in part speaking for others, and not necessarily myself)
this is DIY, and that is assumed. however, because of the pricepoint, and the general attractiveness of this offer, many who were previously unaware of the functionality of active crossovers have become interested. this thread has been technical to say the least.
for somene who is unaware of how an active crossover works, its VERY confusing. simply saying you need a HP filter with a few buffers, etc... gets confusing. i know that for my maggies, i needed a simple 2-way 2nd order crossover. but i was initially unaware as to what a buffer was, why i needed one, and am still a bit uncertain of why 1 input and 2 output buffers are needed.
just keep in mind that we al have to learn somehow. questions will arise. and of couse, the most common question will be "for my situation, what is needed". and until your post just now, it hasnt been 100% clear for most people.
but now there should be little excuse for not knowing at least WHAT you need. how to impliment could be another issue though 🙂
(btw, i am in part speaking for others, and not necessarily myself)
OK, I see how it happened. But actually this project is a great way to experiment safely and cheaply with crossovers, much better than passive x-o which are so hard to model and driver/amp/cable dependent. In fact even if ppl didn't really know what they let themselves into, they've unconsciously chosen the easiest way to do it 😉
Why you need the buffers:
one input buffer serves all x-o channels. It is used to ensure that the following stages see a low source impedance. The source impedance from the preamp depends on the specific preamp, so one can not be sure of the value. It may be high, say 1 k or more. The source impedance determines the filter response, because it will become part of the RC network around the filter op amp. Therefore it is good to have an input buffer just to make sure the source impedance in front of the filter op amp is known, and low.
The output buffer is there to make sure that the output can supply enough current to drive cables to the power amps. The last filter op amp in the line before output has already the filter network to drive, that takes away some current. It is best to add a buffer after it. The buffer has no filter load to drive and can dedicate all its current to the output. A two-way filter will need 2 outputs, so it needs 2 output buffers. But just one input buffer, common to the lo and hi filter section inputs.
Why you need the buffers:
one input buffer serves all x-o channels. It is used to ensure that the following stages see a low source impedance. The source impedance from the preamp depends on the specific preamp, so one can not be sure of the value. It may be high, say 1 k or more. The source impedance determines the filter response, because it will become part of the RC network around the filter op amp. Therefore it is good to have an input buffer just to make sure the source impedance in front of the filter op amp is known, and low.
The output buffer is there to make sure that the output can supply enough current to drive cables to the power amps. The last filter op amp in the line before output has already the filter network to drive, that takes away some current. It is best to add a buffer after it. The buffer has no filter load to drive and can dedicate all its current to the output. A two-way filter will need 2 outputs, so it needs 2 output buffers. But just one input buffer, common to the lo and hi filter section inputs.
excellent, low-tech explaination. that should help many people.
i agree, the crossover is something rarely tinkered with, because the traditional passive is VERY difficult to really tweak. the active is made for this, but is not all that common, and reserved for the more experienced DIY'er... until now 🙂
i'm hoping the active crossover will take my speakers to the next dimension. with the active crossover, an aleph3 on highs, and aleph2 on the lows, i hope to create unreal audio 🙂
i agree, the crossover is something rarely tinkered with, because the traditional passive is VERY difficult to really tweak. the active is made for this, but is not all that common, and reserved for the more experienced DIY'er... until now 🙂
i'm hoping the active crossover will take my speakers to the next dimension. with the active crossover, an aleph3 on highs, and aleph2 on the lows, i hope to create unreal audio 🙂
- Status
- Not open for further replies.