usekgb
Well-known member
JBL still has T4B's in stock, just not in the tent sale. I'm not defending JBL here, but I'm just trying to quell a few wild rumors.
Cheers,
Zach
Cheers,
Zach
T4b ownage
- Thread starter dripelectronics
- Start date
Help Support GroupDIY Audio Forum:
dissonantstring
Well-known member
hi greg,
great initiative and if you're offering matched LDRs that fit the specs CJ has done the research for, we are set! no more worries (hopefully) for T4s, especially for guys in the EU. thanks for doing this one!
i'm in for a couple (depending on price,cause most of us are cheap bastards!) :green:
great work!
-grant
great initiative and if you're offering matched LDRs that fit the specs CJ has done the research for, we are set! no more worries (hopefully) for T4s, especially for guys in the EU. thanks for doing this one!
i'm in for a couple (depending on price,cause most of us are cheap bastards!) :green:
great work!
-grant
ciminosound
Well-known member
Come on CJ toot your own horn dude! The original research. Wasn't this originally done in the "old place"?
http://www.vacuumbrain.com/docs/t5.html
And some general LA@A info from Kev et al.
http://www.diyfactory.com/projects/diyla2/diyla2.htm
What's old around here is new again! Where have all the old timers gone?!?!
http://www.vacuumbrain.com/docs/t5.html
And some general LA@A info from Kev et al.
http://www.diyfactory.com/projects/diyla2/diyla2.htm
What's old around here is new again! Where have all the old timers gone?!?!
dissonantstring
Well-known member
[quote author="ciminosound"]Come on CJ toot your own horn dude! The original research. Wasn't this originally done in the "old place"?
http://www.vacuumbrain.com/docs/t5.html
And some general LA@A info from Kev et al.
http://www.diyfactory.com/projects/diyla2/diyla2.htm
What's old around here is new again! Where have all the old timers gone?!?![/quote]
nah, CJ is too modest. He genuinely has his heart set on helping others with DIY without pretense. all of this has been researched long before with great documentation and is well appreciated.
i think drip is doing a great service with this one as people (I'm guilty as well) just like the ease of not having to buy a lot of LDRs, having to match them and sourcing the EL panels in large quantities. i'm lazy and it seems that drip really enjoys (i hope, not speaking for greg) and has the patience to get these kits together. i don't think greg is claiming that he's pioneering the research in this, just going about it in his way. just my $.02
it's all good.
regards,
grant
http://www.vacuumbrain.com/docs/t5.html
And some general LA@A info from Kev et al.
http://www.diyfactory.com/projects/diyla2/diyla2.htm
What's old around here is new again! Where have all the old timers gone?!?![/quote]
nah, CJ is too modest. He genuinely has his heart set on helping others with DIY without pretense. all of this has been researched long before with great documentation and is well appreciated.
i think drip is doing a great service with this one as people (I'm guilty as well) just like the ease of not having to buy a lot of LDRs, having to match them and sourcing the EL panels in large quantities. i'm lazy and it seems that drip really enjoys (i hope, not speaking for greg) and has the patience to get these kits together. i don't think greg is claiming that he's pioneering the research in this, just going about it in his way. just my $.02
it's all good.
regards,
grant
ciminosound
Well-known member
Oh I don't mean to imply anything! The more info and people helping others is what this place is all about! Kudos to the guys who can make the PCs and source parts for those who might have a hard time doing so. drip is providing an invaluable service. Hell I got a T4b from CJ ages ago. At the time I was in no postion to make my own.
I just think everyone should have the most info possible on what they are trying to do. I'd hate to see this place just become a kit and paint by numbers only place that's all. It's a great place to learn what makes this stuff tick and why.
It's just that CJ is one of the few of us old guys who seem to still be around all the time and he has, and hopefully will continue to contribute so much.
Run it up the flagpole matie!!
:sam: :sam: :sam: :sam: :sam: :sam:
I just think everyone should have the most info possible on what they are trying to do. I'd hate to see this place just become a kit and paint by numbers only place that's all. It's a great place to learn what makes this stuff tick and why.
It's just that CJ is one of the few of us old guys who seem to still be around all the time and he has, and hopefully will continue to contribute so much.
Run it up the flagpole matie!!
:sam: :sam: :sam: :sam: :sam: :sam:
dissonantstring
Well-known member
[quote author="ciminosound"]Oh I don't mean to imply anything! The more info and people helping others is what this place is all about! Kudos to the guys who can make the PCs and source parts for those who might have a hard time doing so. drip is providing an invaluable service. Hell I got a T4b from CJ ages ago. At the time I was in no postion to make my own.
I just think everyone should have the most info possible on what they are trying to do. I'd hate to see this place just become a kit and paint by numbers only place that's all. It's a great place to learn what makes this stuff tick and why.
[/quote]
point well taken ciminosound and i agree with you.
[quote author="cinminosound"]It's just that CJ is one of the few of us old guys who seem to still be around all the time and he has, and hopefully will continue to contribute so much.
Run it up the flagpole matie!! [/quote]
Aye, CJ be one of the greats. Aaaarrrrgh! (i've been thinking more and more that we need a pirate emoticon) :grin:
-grant
I just think everyone should have the most info possible on what they are trying to do. I'd hate to see this place just become a kit and paint by numbers only place that's all. It's a great place to learn what makes this stuff tick and why.
[/quote]
point well taken ciminosound and i agree with you.
[quote author="cinminosound"]It's just that CJ is one of the few of us old guys who seem to still be around all the time and he has, and hopefully will continue to contribute so much.
Run it up the flagpole matie!! [/quote]
Aye, CJ be one of the greats. Aaaarrrrgh! (i've been thinking more and more that we need a pirate emoticon) :grin:
-grant
I got to get my act together and get Kid Squid this LSI info.
He was mulling over a group buy of EL panels, the hardest part to source.
That would be a UK deal.
Maybe if that comes off OK, someone can repeat it for the US.
He was mulling over a group buy of EL panels, the hardest part to source.
That would be a UK deal.
Maybe if that comes off OK, someone can repeat it for the US.
ciminosound
Well-known member
DITTO!! :twisted:
mfdu
Well-known member
can i just point out that if all you seppo's reckon $206 is a bit steep for the JBL t4b's then just wait till you convert that into the australian peso!!!!
the dripster is my friend, the dripster is my friend, the dripster is my friend
chris
the dripster is my friend, the dripster is my friend, the dripster is my friend
chris
jetboatguy
Well-known member
I too, also have 2 x Drip Electronics PCB's on the work bench without any T4 cells... this a great intiative on Drip's part, and you can certainly count me in for at least 2 x T4 kits.
The UA conspiracy to dry up all T4 cells, would seem like UA are shooting themselves in the foot, making this DIY thing a bigger growth market because of pricy UA replacement parts.
PS- I am Canadian, and take no offence...
The UA conspiracy to dry up all T4 cells, would seem like UA are shooting themselves in the foot, making this DIY thing a bigger growth market because of pricy UA replacement parts.
PS- I am Canadian, and take no offence...
Neil
Well-known member
Great job, Greg!! (cheers!) I'm in for at least one immediately and a couple more later.
I can't thank you enough, but I can certainly add my voice to the others here.
Neil
I can't thank you enough, but I can certainly add my voice to the others here.
Neil
dripelectronics
Well-known member
this is gonna be fun ,
credit is due to cj :thumb:
ill start posting the results and research as things come togeather
over the next week or so ,
in the mean time i have probably 300 photocells just staring at me.
what will be an interesting side project is expirimenting
with cells with faster and slower attack times.
i doubt ua had anything to do with the t4 buy out ,
youll probaly start seeing these hit ebay or something ,
i saw one the other day for 150$ in a box from jbl.
any ways their research probably yields a better more consistant t4 then urei.
http://uaudio.com/webzine/2003/july/index4.html
matching the cells is no so important , it's just getting the one cell
used for the actual gain reduction to have proper specs.
as for the cell wich is used for reduction metering , i find
plus or minus 10% ok w me , there is after all a matching
resistor AKA R25 and is usually a 33k.
[quote author="gyraf"]There's little or no reason to use a matched second-cell for the GR meter - after all, how important is exactly-precise GR-metering? Just use any LDR that makes decent results, and use your matched cells for stereo operation..
Jakob E.[/quote]
ill have to explore the matching resistor concepts a little ,
but Djahsen's la2 book has a page dedicated to the matching resistor.
(cant believe i still refer to that book , especially since i memorized
the la-2a and can build one with out a diagram,...lol)
the urei t4b matching resistor from JBL are always a 33k , at least all the ones i recieved.
like i said , lot's of kinks to work out , but i hope in the next weeks
this all will be solved.
thanks for the input ,
g,
credit is due to cj :thumb:
ill start posting the results and research as things come togeather
over the next week or so ,
in the mean time i have probably 300 photocells just staring at me.
what will be an interesting side project is expirimenting
with cells with faster and slower attack times.
i doubt ua had anything to do with the t4 buy out ,
youll probaly start seeing these hit ebay or something ,
i saw one the other day for 150$ in a box from jbl.
any ways their research probably yields a better more consistant t4 then urei.
http://uaudio.com/webzine/2003/july/index4.html
matching the cells is no so important , it's just getting the one cell
used for the actual gain reduction to have proper specs.
as for the cell wich is used for reduction metering , i find
plus or minus 10% ok w me , there is after all a matching
resistor AKA R25 and is usually a 33k.
[quote author="gyraf"]There's little or no reason to use a matched second-cell for the GR meter - after all, how important is exactly-precise GR-metering? Just use any LDR that makes decent results, and use your matched cells for stereo operation..
Jakob E.[/quote]
ill have to explore the matching resistor concepts a little ,
but Djahsen's la2 book has a page dedicated to the matching resistor.
(cant believe i still refer to that book , especially since i memorized
the la-2a and can build one with out a diagram,...lol)
the urei t4b matching resistor from JBL are always a 33k , at least all the ones i recieved.
like i said , lot's of kinks to work out , but i hope in the next weeks
this all will be solved.
thanks for the input ,
g,
dripelectronics
Well-known member
lol , just examining wave forms of 50% turn in reduction and a bass note.
..............................
thanks Mkoz
, as i begin the course of attack , i definiatly
appreciate the offer.
g.
If a batch of 5210 cells come in wrong, then you can re-order a spec up or a spec down, for instance, the 5210 is to slow, or dcr off/on not right, get the 5220.
I have a bunch of different p/n's up and down from the stock cell that I have yet to try.
So still plent of room for experimentation and DIY tweaks, like haveing two sets of cells in the same T4 box, with a sw conneted to go between, wires run into un used octal pins ( ditcxh some of the grounds)
I have a bunch of different p/n's up and down from the stock cell that I have yet to try.
So still plent of room for experimentation and DIY tweaks, like haveing two sets of cells in the same T4 box, with a sw conneted to go between, wires run into un used octal pins ( ditcxh some of the grounds)
rafafredd
Well-known member
Please!!!! Give us some ready to go T4s... Please!
To get around this problem I wonder if one could measure the voltage across the reduction photocell and the voltage across resistor from the input and the top photocell.
How big are the voltages? maybe Fet input opamps?
And them make a circuit to drive a meter. Add the voltages together and take a ratio?
How big are the voltages? maybe Fet input opamps?
And them make a circuit to drive a meter. Add the voltages together and take a ratio?
Zee1usa
Well-known member
I will most likely be in for 2 of these. :thumb:
oh..and maybe 2 of your boards also.
z
oh..and maybe 2 of your boards also.
z
I spent some time building T4s back in the mid-to-late nineties. Here's a link to some info on the T4 tester I built back in '97...
http://www.kenetek.com/OtherProjects/KenetekT4Tester/tabid/195/Default.aspx
Sorry about the grainy pictures; they were taken back then with a first-generation Sony digital camera. That's as good as digital pics got then.
I'll be updating the site as time permits. I've got some pics of some very interesting T4 units, including a very early one that uses a paper clip as an integral part of the assembly. No PCB required!
I've never tested the NSL 5910 but tested and rejected the NSL 5920 many years ago. I'll have to go back an review the test results to see why. I'm going to order some 5910's to test and will post the results ASAP when available.
Note: I just changed the DNS to make the site live so some of you might get the "Coming Soon" page. Try back tomorrow and the "live" site should show up for you. Thanks!!!
http://www.kenetek.com/OtherProjects/KenetekT4Tester/tabid/195/Default.aspx
Sorry about the grainy pictures; they were taken back then with a first-generation Sony digital camera. That's as good as digital pics got then.
I'll be updating the site as time permits. I've got some pics of some very interesting T4 units, including a very early one that uses a paper clip as an integral part of the assembly. No PCB required!
I've never tested the NSL 5910 but tested and rejected the NSL 5920 many years ago. I'll have to go back an review the test results to see why. I'm going to order some 5910's to test and will post the results ASAP when available.
Note: I just changed the DNS to make the site live so some of you might get the "Coming Soon" page. Try back tomorrow and the "live" site should show up for you. Thanks!!!
[quote author="dripelectronics"]this is gonna be fun ,
credit is due to cj :thumb:
ill start posting the results and research as things come togeather
over the next week or so ,
in the mean time i have probably 300 photocells just staring at me.
what will be an interesting side project is expirimenting
with cells with faster and slower attack times.
i doubt ua had anything to do with the t4 buy out ,
youll probaly start seeing these hit ebay or something ,
i saw one the other day for 150$ in a box from jbl.
any ways their research probably yields a better more consistant t4 then urei.
http://uaudio.com/webzine/2003/july/index4.html
matching the cells is no so important , it's just getting the one cell
used for the actual gain reduction to have proper specs.
as for the cell wich is used for reduction metering , i find
plus or minus 10% ok w me , there is after all a matching
resistor AKA R25 and is usually a 33k.
[quote author="gyraf"]There's little or no reason to use a matched second-cell for the GR meter - after all, how important is exactly-precise GR-metering? Just use any LDR that makes decent results, and use your matched cells for stereo operation..
Jakob E.[/quote]
ill have to explore the matching resistor concepts a little ,
but Djahsen's la2 book has a page dedicated to the matching resistor.
(cant believe i still refer to that book , especially since i memorized
the la-2a and can build one with out a diagram,...lol)
the urei t4b matching resistor from JBL are always a 33k , at least all the ones i recieved.
like i said , lot's of kinks to work out , but i hope in the next weeks
this all will be solved.
thanks for the input ,
g,[/quote]
I'm pretty sure the buy-out was perpetrated by a company called Studio Electronics. I bought a unit from them off Ebay and it's the real thing. I see their auctions fairly frequently for T4Bs.
As for the matching resistor, just use a 50k pot instead, and tweak the pot as needed. In the units I built using the Sifam AL39WF "VU" meter (the quotes around VU are because this meter doesn't have true VU ballistics), I could only get within about +/- 1 dB across the whole range. I adjusted the pot so that the meter was dead on at 6 dB gain reduction, because that suited my mixing style best.
I've found that an accurate meter is better than an approximation, especially when trying to just take the edge off a vocal by barely compressing it.
credit is due to cj :thumb:
ill start posting the results and research as things come togeather
over the next week or so ,
in the mean time i have probably 300 photocells just staring at me.
what will be an interesting side project is expirimenting
with cells with faster and slower attack times.
i doubt ua had anything to do with the t4 buy out ,
youll probaly start seeing these hit ebay or something ,
i saw one the other day for 150$ in a box from jbl.
any ways their research probably yields a better more consistant t4 then urei.
http://uaudio.com/webzine/2003/july/index4.html
matching the cells is no so important , it's just getting the one cell
used for the actual gain reduction to have proper specs.
as for the cell wich is used for reduction metering , i find
plus or minus 10% ok w me , there is after all a matching
resistor AKA R25 and is usually a 33k.
[quote author="gyraf"]There's little or no reason to use a matched second-cell for the GR meter - after all, how important is exactly-precise GR-metering? Just use any LDR that makes decent results, and use your matched cells for stereo operation..
Jakob E.[/quote]
ill have to explore the matching resistor concepts a little ,
but Djahsen's la2 book has a page dedicated to the matching resistor.
(cant believe i still refer to that book , especially since i memorized
the la-2a and can build one with out a diagram,...lol)
the urei t4b matching resistor from JBL are always a 33k , at least all the ones i recieved.
like i said , lot's of kinks to work out , but i hope in the next weeks
this all will be solved.
thanks for the input ,
g,[/quote]
I'm pretty sure the buy-out was perpetrated by a company called Studio Electronics. I bought a unit from them off Ebay and it's the real thing. I see their auctions fairly frequently for T4Bs.
As for the matching resistor, just use a 50k pot instead, and tweak the pot as needed. In the units I built using the Sifam AL39WF "VU" meter (the quotes around VU are because this meter doesn't have true VU ballistics), I could only get within about +/- 1 dB across the whole range. I adjusted the pot so that the meter was dead on at 6 dB gain reduction, because that suited my mixing style best.
I've found that an accurate meter is better than an approximation, especially when trying to just take the edge off a vocal by barely compressing it.
Similar threads
Latest posts
-
-
-
Calculating capacitors after bridge rectifier and before regulator.- Latest: Cqwet Dbdfte
-
-
-
-
