Its a long shot, but was curious if anyone has a pair of 18W/8531G drivers they would be willing to part with.
Thx
D
Thx
D
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WTB: Scan-Speak 18W/8531G
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Rockford Fosgate Prime R500x1D
I just received a prime 500x1d I don't see anything shorted or bad except two diodes on the power supply. It's using the t460 mosfets. Two diodes d16 and d8 are bad. Anyone know the voltage of these two diodes?
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NAP 200 - part list
Hi
I have a PCB to build a NAP 200 Clone. The different parts are listed on the PCB, but to avoid stuppid errors I am hoping that some one have the part list written down and would like to share it!
I have googled alot without succes :-(
/Thomas
I have a PCB to build a NAP 200 Clone. The different parts are listed on the PCB, but to avoid stuppid errors I am hoping that some one have the part list written down and would like to share it!
I have googled alot without succes :-(
/Thomas
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New Markaudio Drivers
Hello all,
As hinted at here and there, Mark has some new drivers on the horizon in the Alpair range.
18 months ago after we successfully released the Pluvia range of drivers, which have been well received, Mark set about the next design evolution. As some of you will know Mark's design ethos is mechanical efficiency, adding lightness and simplifying where possible. In these new drivers Mark has managed to achieve much more with much less.
One of the things that frustrated some of Mark's previous design efforts was the rear suspension being a pain in the ***. The necessity of it leading to design compromise. Freed from the necessity, drivers could be lighter, have tighter production tolerances and could be much more linear through the whole excursion range.
For these new drivers Mark has spent countless engineering hours trying to engineer out this need, not only did he find a solution but it helped him solve another long held desire - greater dispersion. For a long time now the drivers have used Aerospace grade alloys for stiffness, allowing shallower cone profiles. The multiform cone pressing process has allowed Mark to use complex cone profiles to enhance the stiffness further and increase dispersion. The new cones take this concept even further.
The removal of the spider means moving the centre of gravity of the whole drive train so that it can balance without the need for the spider at that centre. Removing the spider allows space for the magnet and the coil/former to move forward which helps, but the cone needed making shallower still. The answer to this answer also answered the question of increased dispersion as well, thus killing two birds with one stone. The new cone is negative camber, so not only is it very shallow but the outside edge actually comes back on itself.
The results of this new engineering leap are presented in the all new Alpair7 MS and big brother Alpair 11 MS where MS stands for Mono Suspension.
I've attached a teaser image here and over the next week or two we will get the PDF's uploaded for mass consumption and Scott will be working up some box designs as usual. the A11MS fits straight into a Frugal Horn XL acoustically although it is a little larger so modification will be needed. The 11 also does work in the Pensil 11 although the alignment isn't quite optimal, Scott is working on either a new design or a way we can all modify an existing cabinet, there will be other designs and obviously the A7MS will get the same treatment.
To start with these will be in VERY short supply but rest assured over time stock will increase and obviously the current drivers will still be available for some time to come as well.
![Click the image to open in full size.]()
As hinted at here and there, Mark has some new drivers on the horizon in the Alpair range.
18 months ago after we successfully released the Pluvia range of drivers, which have been well received, Mark set about the next design evolution. As some of you will know Mark's design ethos is mechanical efficiency, adding lightness and simplifying where possible. In these new drivers Mark has managed to achieve much more with much less.
One of the things that frustrated some of Mark's previous design efforts was the rear suspension being a pain in the ***. The necessity of it leading to design compromise. Freed from the necessity, drivers could be lighter, have tighter production tolerances and could be much more linear through the whole excursion range.
For these new drivers Mark has spent countless engineering hours trying to engineer out this need, not only did he find a solution but it helped him solve another long held desire - greater dispersion. For a long time now the drivers have used Aerospace grade alloys for stiffness, allowing shallower cone profiles. The multiform cone pressing process has allowed Mark to use complex cone profiles to enhance the stiffness further and increase dispersion. The new cones take this concept even further.
The removal of the spider means moving the centre of gravity of the whole drive train so that it can balance without the need for the spider at that centre. Removing the spider allows space for the magnet and the coil/former to move forward which helps, but the cone needed making shallower still. The answer to this answer also answered the question of increased dispersion as well, thus killing two birds with one stone. The new cone is negative camber, so not only is it very shallow but the outside edge actually comes back on itself.
The results of this new engineering leap are presented in the all new Alpair7 MS and big brother Alpair 11 MS where MS stands for Mono Suspension.
I've attached a teaser image here and over the next week or two we will get the PDF's uploaded for mass consumption and Scott will be working up some box designs as usual. the A11MS fits straight into a Frugal Horn XL acoustically although it is a little larger so modification will be needed. The 11 also does work in the Pensil 11 although the alignment isn't quite optimal, Scott is working on either a new design or a way we can all modify an existing cabinet, there will be other designs and obviously the A7MS will get the same treatment.
To start with these will be in VERY short supply but rest assured over time stock will increase and obviously the current drivers will still be available for some time to come as well.
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Many things doesn't work on my android (4) mobile
Basically no function works that is applied with a downward triangle. No search, no PM, etc...
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Recharging battery-powered amp while playing
I built a distortion preamp + tda7297 amp with busking in mind. It has 16 AA NiMh batteries plus a 18v regulator (L7818). To recharge the 16 batteries all at once, I'm plugging in a 24v power supply, limiting current with a 50 Ohm resistor in series. Yes, I know this is not the ideal way to treat NiMh batteries, but that's ok for now. The problem is an annoying high-pitched buzz that oscillates in amplitude at around 4 Hz, that makes it impossible to play while recharging.
Why is this happening? Could a diode intersection solve it?
Thanks!
Why is this happening? Could a diode intersection solve it?
Thanks!
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Relieving Zenith 12" of sub 120hz?
So, I have a pair of 12" Zenith CZ full rangers in open baffles. I am thinking of buying a Dayton TPA3116 2.1 amplifier and building a passive subwoofer. The bass channel on the Dayton crosses over at 180 hz which is a bit high but might be good in this case because the Zeniths have a very limited xmax and I've been warned to not push them too hard because of this.
Would it be good to relieve the Zeniths of, let's say 140 hz and below, via a pass filter? If so would a single cap (per driver) achieve this filtering? Before I get into specifics about value of cap and so forth, do you think this is a workable situation? Thanks for any help!
Would it be good to relieve the Zeniths of, let's say 140 hz and below, via a pass filter? If so would a single cap (per driver) achieve this filtering? Before I get into specifics about value of cap and so forth, do you think this is a workable situation? Thanks for any help!
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Rushmore speakers?
Thoughts on their current value and comparisons to newer speakers. Have lx521 and wondered if they would be step up, down. Sideways?
Thanks
Thanks
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Why Car Subs Sound Louder Inside The Cars?
Hello Everyone!
So I wanted to make a subwoofer for PA, Thought if I can use heavier car subs and re-design the box. I already know the pro's and cons (mostly cons, I know) of doing such, and I know that it's because of low internal volume of a car cabin that the air is more easily pressurized. What caught my attention, though was that car subwoofers are louder when placed inside the car, even if you listen from OUTSIDE of the car. How is this possible? Is car cabin acting like a 4th order box, correcting the phase? I can't get my head around it. How can such a random shape with -relatively- flimsy body do such. If it's not doing so, then what is the fact? and if it is doing so, how can we use the fact to our advantage?
Best Regards, Ali
So I wanted to make a subwoofer for PA, Thought if I can use heavier car subs and re-design the box. I already know the pro's and cons (mostly cons, I know) of doing such, and I know that it's because of low internal volume of a car cabin that the air is more easily pressurized. What caught my attention, though was that car subwoofers are louder when placed inside the car, even if you listen from OUTSIDE of the car. How is this possible? Is car cabin acting like a 4th order box, correcting the phase? I can't get my head around it. How can such a random shape with -relatively- flimsy body do such. If it's not doing so, then what is the fact? and if it is doing so, how can we use the fact to our advantage?
Best Regards, Ali
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Capacitors Antitrust Litigation Indirect Purchaser Actions
Does this seem legit?
www.capacitorsindirectcase.com
IN RE CAPACITORS ANTITRUST LITIGATION
ALL INDIRECT PURCHASERS ACTIONS WEBSITE
With the number of caps we buy, there might be a chance to get get something back.
.
www.capacitorsindirectcase.com
IN RE CAPACITORS ANTITRUST LITIGATION
ALL INDIRECT PURCHASERS ACTIONS WEBSITE
With the number of caps we buy, there might be a chance to get get something back.
.
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Question regarding slot port configuration
I've designed and built a subwoofer that would be expected to be tuned to 33 Hz based on WinISD configuration.
However, the port is long profile and has at least one bend in it. From the research I was doing it seemed I could expect that the actual tuning would end up lower than this due to the extra resistance in the long profile.
Oddly enough, the tuning seems to have come out right where WinISD said, judging by cone excursion during test tones. I am now looking to modify the slot port height to modify the tuning lower.
My question is: In such a case with a slot port that has one 90 degree angle in it, is it acceptable to modify only one portion of the port path? Or must the entire port path be modified? Ie, must port profile be entirely uniform throughout? My understanding is that the Hemholtz resonance is affected by the length and the volume contained within, therefore if I reduced the cross section in one portion only the tuning should be reduced (though not as much as if both sections were reduced). Is this correct?
However, the port is long profile and has at least one bend in it. From the research I was doing it seemed I could expect that the actual tuning would end up lower than this due to the extra resistance in the long profile.
Oddly enough, the tuning seems to have come out right where WinISD said, judging by cone excursion during test tones. I am now looking to modify the slot port height to modify the tuning lower.
My question is: In such a case with a slot port that has one 90 degree angle in it, is it acceptable to modify only one portion of the port path? Or must the entire port path be modified? Ie, must port profile be entirely uniform throughout? My understanding is that the Hemholtz resonance is affected by the length and the volume contained within, therefore if I reduced the cross section in one portion only the tuning should be reduced (though not as much as if both sections were reduced). Is this correct?
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Anybody have a favorite Balance Control for tube circuits? (high impedance)
I think there's a problem inherent in using high-gm RF tubes for a Spud style headphone amp. The tubes' gm and gain can vary, a lot. That means channel balance can be off unless you have enough extra gain to add a bit of NFB (I don't) or you have enough tubes of a particular type to find matched pairs (a royal pain).
So I've decided a Balance control is indicated.
Does anybody have a favorite [simple] balance control circuit for high impedance tube circuits?
I found this at Elliott Sound Products:
![Click the image to open in full size.]()
I figure upping the resistance values of the pots can make it work better with vacuum tube sources.
From looking at it, I think the balance pot defines the input resistance. If using a 10k balance pot, with the wiper in the center position, won't the incoming left and right channel signals each see 5k to ground?
I like that it uses just one ganged pot. Perhaps I could use a 100k-log ganged pot for the volume control, and a 50k linear pot for the balance control?
Or this 'better' balance control:
![Click the image to open in full size.]()
The recipe says,
BAL pot = 2.5X value of VOL pot
R = 0.5 the value of the VOL pot
I suppose I could raise the value of the balance control pot to a pretty whopping 250k-L, with R = 47k, and use a 100k volume control pot. Or would 100k bal and 50k vol work well enough, with R = 47k?
Or, perhaps there's a better way to do this.
--
So I've decided a Balance control is indicated.
Does anybody have a favorite [simple] balance control circuit for high impedance tube circuits?
I found this at Elliott Sound Products:
I figure upping the resistance values of the pots can make it work better with vacuum tube sources.
From looking at it, I think the balance pot defines the input resistance. If using a 10k balance pot, with the wiper in the center position, won't the incoming left and right channel signals each see 5k to ground?
I like that it uses just one ganged pot. Perhaps I could use a 100k-log ganged pot for the volume control, and a 50k linear pot for the balance control?
Or this 'better' balance control:
The recipe says,
BAL pot = 2.5X value of VOL pot
R = 0.5 the value of the VOL pot
I suppose I could raise the value of the balance control pot to a pretty whopping 250k-L, with R = 47k, and use a 100k volume control pot. Or would 100k bal and 50k vol work well enough, with R = 47k?
Or, perhaps there's a better way to do this.
--
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Arcam A80 DC offset protection
The amplifier switches into the protection mode after a random time and comes back again. Sometimes the display shows the error message DC OFFSET error. After measuring the DC-OFFSET, both amplifiers (Left and Right) go through the same DC OFFSET variation. Because both DC OFFSET (Left and Right) show the same wrong behavior, it has to be a powersupply problem.
The -15V supply was not stabel. I changed the regulator REG202 and cap C218 but the problem was not solved. After mesuring I found out that ADJ pin of REG202 was floating. An inspection of soldering pointed out that R214 was soldered at one site. So I resolder the end of the resistor and it's fixed.
![Click the image to open in full size.]()
The -15V supply was not stabel. I changed the regulator REG202 and cap C218 but the problem was not solved. After mesuring I found out that ADJ pin of REG202 was floating. An inspection of soldering pointed out that R214 was soldered at one site. So I resolder the end of the resistor and it's fixed.
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PP amp, 50Hz distorted
Hey there!
I'm working a very simple classic 6BQ5 PP circuit, at first sight everything seems Ok, adecuate OT primary inductance, adecuate vgk input stage , good headroom concertina splitter, and so on; then I realized the circuit ins't capable of put a 50Hz continuous sinewave (12V peak), if not highly distorted, where the 1Khz performance, same level, is very acceptable. My error for sure, what I'm missing?
Thanks in advance for any suggestion.
J.
I'm working a very simple classic 6BQ5 PP circuit, at first sight everything seems Ok, adecuate OT primary inductance, adecuate vgk input stage , good headroom concertina splitter, and so on; then I realized the circuit ins't capable of put a 50Hz continuous sinewave (12V peak), if not highly distorted, where the 1Khz performance, same level, is very acceptable. My error for sure, what I'm missing?
Thanks in advance for any suggestion.
J.
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Morel TSCM 634 Break-in Time?
I just received 2 new Morel TSCM "midrange" drivers. Has anyone opinions and experiences on break-in time for these? Right out of the package they sound good (ie OK) but NOT great. I have some Alpair 7P driers that have WAY more resolution and quicker transient response, etc. I'm hoping this is maybe just a break-in issue! BTW, I have the Morels in a closed box (about 1/2 ft^3) with 50% stuffing, running straight, no X/O.
If not, these are going back soon!!! No way do these Morels sound like they are worth $400 each when the humble MA 7P's can do WAY better for less than 5 times the price!
Thanks!
If not, these are going back soon!!! No way do these Morels sound like they are worth $400 each when the humble MA 7P's can do WAY better for less than 5 times the price!
Thanks!
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Decca Kelly ribbon tweeter with Philips fullrange
Hi,
Does anyone have experience with the Decca Kelly horn ribbon tweeters?
I have a pair of the Kelly Romagna mk2 and the Decca London, which I'd like to use with a 12" fullrange driver.
My plan is to use one of those ribbon tweeters with a Philips/Norelco fullrange driver (9762/05).
The fullrange driver is 8 ohm, frequency response of 30 to 12,000 Hz, and sensitivity is 99 db/W/m (see attached graph)
I am thinking to cross the tweeter at 8,000 Hz.
Any advice or tips on this?
Thanks in advance
Does anyone have experience with the Decca Kelly horn ribbon tweeters?
I have a pair of the Kelly Romagna mk2 and the Decca London, which I'd like to use with a 12" fullrange driver.
My plan is to use one of those ribbon tweeters with a Philips/Norelco fullrange driver (9762/05).
The fullrange driver is 8 ohm, frequency response of 30 to 12,000 Hz, and sensitivity is 99 db/W/m (see attached graph)
I am thinking to cross the tweeter at 8,000 Hz.
Any advice or tips on this?
Thanks in advance
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how might this 2 cubic foot airspace horn sim perform & fold?
- would want it easy to build, and have smooth response
- wondering if such a little horn placed in a corner would work reasonably well (?) It could probably be tweaked or made somewhat larger to lower its cutoff.
![Click the image to open in full size.]()
- wondering if such a little horn placed in a corner would work reasonably well (?) It could probably be tweaked or made somewhat larger to lower its cutoff.
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FS. Black Beauty SYMASYM pcb set
For sale:
- 2 PCBs "Black Beauty SYMASYM", with Backend PSU, Frontend CapMultiplier and Speaker Protection on board
- NJW0281G 4pcs and NJW0302G 4pcs
The price: 45 + shipping + paypall.
Best regards
- 2 PCBs "Black Beauty SYMASYM", with Backend PSU, Frontend CapMultiplier and Speaker Protection on board
- NJW0281G 4pcs and NJW0302G 4pcs
The price: 45 + shipping + paypall.
Best regards
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Taking measurements without proper gear
Hey, so I'm doing my first two-way build using SB Scoustics SB17MFC35-8 and the Vifa XT25SC90-4. I've done a couple sub the past so I'm all good on cab design. I'm also relatively confident in my ability to design a x-over although I'm sure I still have a lot to learn.
So hears the issue, I don't have an Omni mic. Now this is just a project for a mate so he can DJ in his bedroom for fun so it's doesn't have to be perfect. So I had the idea of using my AT2020 to record the frequency response of the drivers when they're in the cab so I can design an x-over and then just try and match the response in xsim to that of the AT2020's response graph. I realise this will hurt a lot of people and everyone is just going to say buy the proper gear, but that's not an option right now, so do you guys think that my idea will allow me to produce an acceptable crossover?
Thanks in advance
So hears the issue, I don't have an Omni mic. Now this is just a project for a mate so he can DJ in his bedroom for fun so it's doesn't have to be perfect. So I had the idea of using my AT2020 to record the frequency response of the drivers when they're in the cab so I can design an x-over and then just try and match the response in xsim to that of the AT2020's response graph. I realise this will hurt a lot of people and everyone is just going to say buy the proper gear, but that's not an option right now, so do you guys think that my idea will allow me to produce an acceptable crossover?
Thanks in advance
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Ferrofluid tweeters
Is there a way to test / check ferrofluid performance? I have a pair of ScanSpeak D2905/970000 that have been sitting for two years, still boxed.
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