Hello, wondering if anyone out there could advise me on how to get the tuner up and running. I've got a QUAD FM 4 tuner that is not powering up. Have checked the fuse which is ok and have replaced the Rifa cap that was bulging. Have power up to the transformer so not the on/off button. I've got an analogue meter and very keen to try to sort problem(s) myself but just need some guidance if possible. Regards
↧
Quad FM 4 not working.
↧
DMM # of digits versus ADC bits
Hi guys,
I was wondering how to compare DMM # of digits versus ADC bits. Let me explain. Suppose I have a 5.5 digit DMM. On the 10V range the last digit would then indicate 00.001V is 1mV. If I have a 16bit ADC that is almost 100dB dynamic range, lets take 100dB for the discussion. That's a factor 10^5, so if I input 10V to the ADC the LSB would be 0.1mV.
Is that reasoning correct?
Background: I have a 16bit USB scope and the software can also display the signal in a voltmeter format. That voltmeter shows 6 digits, with the last one fluctuating all the time. I can set it to 5 digits and then it is steady. Just trying to get my head around the numbers and accuracy.
Jan
I was wondering how to compare DMM # of digits versus ADC bits. Let me explain. Suppose I have a 5.5 digit DMM. On the 10V range the last digit would then indicate 00.001V is 1mV. If I have a 16bit ADC that is almost 100dB dynamic range, lets take 100dB for the discussion. That's a factor 10^5, so if I input 10V to the ADC the LSB would be 0.1mV.
Is that reasoning correct?
Background: I have a 16bit USB scope and the software can also display the signal in a voltmeter format. That voltmeter shows 6 digits, with the last one fluctuating all the time. I can set it to 5 digits and then it is steady. Just trying to get my head around the numbers and accuracy.
Jan
↧
↧
3D printed conical horn throat for Unity/Synergy
Since I started playing around in Fusion360 and have a reliable 3D printer equipped guy, I would like to design my own 3D printed round-to-conical 1" compression driver adapter, that would allow mounting cardboard/EPS/plywood sides for easy construction. I think I saw something like that already, but I cannot find where it was.
What would be a good angle to start? 60x40, 60x60 or 90x60? And like with all my amateur 3D designs, I will be happy to share the result here.
What would be a good angle to start? 60x40, 60x60 or 90x60? And like with all my amateur 3D designs, I will be happy to share the result here.
↧
TechFX Reflow Controller kit $1
I never put this together -- requires you purchase a Black and Decker toaster oven -- this is the parts -- 2 controllers, Omega Thermocouple, Croydom SSR's, Matrix Orbital Keypad and LCD Display.
(Why I have 2 controllers, I don't know....???).
Basically, it's yours for the shipping. The $1.00 will cover the Paypal fees.
PM Me if interested. I am using the Controleo 3 and need only one oven.
(Why I have 2 controllers, I don't know....???).
Basically, it's yours for the shipping. The $1.00 will cover the Paypal fees.
PM Me if interested. I am using the Controleo 3 and need only one oven.
↧
crossover design- depth of field
Hi All,
I embarked on this projet 3 yrs ago having spent nearly a year reading this forum. There is so much knowledge here I cant begin to explain how humble I feel.
Anyway I built a three way with the Peerless 830452, SB satori 16mw8, and sb29rdc, crossed at approx 120 and 1800Hz. I designed the crossovers (many thanks to AllenB and Bwaslo) .
I have now reached a point where the speakers are totally and I mean totally invisible, BUT the downside is that the soundstage is two dimensional, and has no (illusion) of depth. is this something that can be designed in or does the speakers disappearing act kinda preclude that... one or the other?
I deliberately haven't posted any circuits etc yet cos I want to learn:)
many thanks
Andrew
I embarked on this projet 3 yrs ago having spent nearly a year reading this forum. There is so much knowledge here I cant begin to explain how humble I feel.
Anyway I built a three way with the Peerless 830452, SB satori 16mw8, and sb29rdc, crossed at approx 120 and 1800Hz. I designed the crossovers (many thanks to AllenB and Bwaslo) .
I have now reached a point where the speakers are totally and I mean totally invisible, BUT the downside is that the soundstage is two dimensional, and has no (illusion) of depth. is this something that can be designed in or does the speakers disappearing act kinda preclude that... one or the other?
I deliberately haven't posted any circuits etc yet cos I want to learn:)
many thanks
Andrew
↧
↧
Hello from Indiana
Hello all, I've been lurking for a while and finally signed up as I'm getting closer to actually getting started on my project.
I'm a member on the AVS forums and had some great help there a couple years ago when I first set up my home theater. Needless to say I quickly ran out of money investing in good speakers and amp and had to postpone my plans for a dedicated stereo setup. The original plan was to use the Oppo Sonica DAC with a Marantz 7025 Power Amp. Unfortunately Oppo has discontinued making their high end products, and hence my pursuit of building a custom DAC. I want to build something as close to the Sonica as I can get away with using some of the ESS or AKM boards available (with possibly upgrading components). I am looking forward to the project and would greatly appreciate any help I can get.
I'm a member on the AVS forums and had some great help there a couple years ago when I first set up my home theater. Needless to say I quickly ran out of money investing in good speakers and amp and had to postpone my plans for a dedicated stereo setup. The original plan was to use the Oppo Sonica DAC with a Marantz 7025 Power Amp. Unfortunately Oppo has discontinued making their high end products, and hence my pursuit of building a custom DAC. I want to build something as close to the Sonica as I can get away with using some of the ESS or AKM boards available (with possibly upgrading components). I am looking forward to the project and would greatly appreciate any help I can get.
↧
FS a LynxTWO-A model PCI Sound card
LynxTWO-A model, with four analog inputs and outputs with all of the breakout cables
This is a used full-size PCI sound card .
Lynx Two 24-bit/192kHz Multi-channel Audio Interface
A model also provide comprehensive digital I/O facilities: a single digital in and out in either AES-EBU or S/PDIF format.
All the analogue I/O emerges from an L2Audio 25-way D-type connector, which interfaces with a 1.8-metre-long multiway cable a full 14mm thick, terminating in eight XLR plugs and sockets
The Price for the used LynxTWO A Model with the breakout cables $450.00 Plus Shipping
This is a used full-size PCI sound card .
Lynx Two 24-bit/192kHz Multi-channel Audio Interface
A model also provide comprehensive digital I/O facilities: a single digital in and out in either AES-EBU or S/PDIF format.
All the analogue I/O emerges from an L2Audio 25-way D-type connector, which interfaces with a 1.8-metre-long multiway cable a full 14mm thick, terminating in eight XLR plugs and sockets
The Price for the used LynxTWO A Model with the breakout cables $450.00 Plus Shipping
↧
Tokin SIT THF51S curves high tension low current
Here some infos about THF51S curves at low current high tension measured with ROE TEST by Helmut Weigl. More interesting the link in which Helmut analyzes the four samples I sent him
http://www.roehrentest.de/SIT_EN.pdf
http://www.roehrentest.de/SIT_EN.pdf
↧
DIY All-in-one Experimental Amp
Dear DIYaudios,
May I submit a project to your watchful eyes? It's something I've been planning a long time, and I think it's time I actually gather my wits and try to build it.
I want this to be the base for twiddling as many knobs and switches as possible to be able to experiment with voicing and sound generation in an amp. In the case of a good outcome I want to build a few stripped-down versions of this with what I learned from this particular monster as background.
I attached the current schematic for this.
There's some points I should make clear beforehand: The "BOOST" double-throw is actually a relay, all other switches are the common kind, the "BIAS" switch will only be toggled when power is off. The base for all this mayhem are Merlin B.s excellent Universal PCBs since I come from stompboxes and so I'm used to PCBs. I'm willing to expand my preciously little knowledge in the fields of point-to-point and other advanced techniques, but for this I feel I'm safer with those I feel comfortable with.
If you would cast a scrutinizing eye on my project to help me find fatal flaws in the contruct I'd be very glad! Thank you in advance whoever gives this a once-over!
May I submit a project to your watchful eyes? It's something I've been planning a long time, and I think it's time I actually gather my wits and try to build it.
I want this to be the base for twiddling as many knobs and switches as possible to be able to experiment with voicing and sound generation in an amp. In the case of a good outcome I want to build a few stripped-down versions of this with what I learned from this particular monster as background.
I attached the current schematic for this.
There's some points I should make clear beforehand: The "BOOST" double-throw is actually a relay, all other switches are the common kind, the "BIAS" switch will only be toggled when power is off. The base for all this mayhem are Merlin B.s excellent Universal PCBs since I come from stompboxes and so I'm used to PCBs. I'm willing to expand my preciously little knowledge in the fields of point-to-point and other advanced techniques, but for this I feel I'm safer with those I feel comfortable with.
If you would cast a scrutinizing eye on my project to help me find fatal flaws in the contruct I'd be very glad! Thank you in advance whoever gives this a once-over!
↧
↧
quastion about these 3 drivers for a 3-way
is Dayton Audio PT2C-8 Planar Tweeter a good combination with Dayton Audio RS125P-8 5" (midrange) and Dayton Audio RS180P-8 7" (woofer) for a 3-way.
or is a (a little bit cheaper) tweeter better?
and if it is a good combo will someone willingly to help me to design a passive crossover?
it is my first time making a DIY speaker
thanks!
or is a (a little bit cheaper) tweeter better?
and if it is a good combo will someone willingly to help me to design a passive crossover?
it is my first time making a DIY speaker
thanks!
↧
2sc5200 / NJW0302 SOA
Hi guys ,
how much power do you think can be pulled out of 12pairs of 2sc5200 or NJW0302G on a 110VDC rail on 4ohms there will ample cooling and short-circuit protection based on hall effect sensors. I am confused because i see profession companies pulling out 800+ watts out of only 7pairs do they not calculate SOA?
I am talking about simple class Ab no class h or g ....
how much power do you think can be pulled out of 12pairs of 2sc5200 or NJW0302G on a 110VDC rail on 4ohms there will ample cooling and short-circuit protection based on hall effect sensors. I am confused because i see profession companies pulling out 800+ watts out of only 7pairs do they not calculate SOA?
I am talking about simple class Ab no class h or g ....
↧
Rotel RB-971 advise needed
hi everyone i'm new here
i have recently brought a second hand rotel RB-971 to replace my RB-850. i use the amp as a bridged mono to power a subwoofer. the RB-850 is 100 watts and the RB-971 is supposed to be 180 watts, the problem is that the RB-971 is no louder than the RB-850 and if anything has slightly worse sound quality.
i have read about replacing capacitors(which i am prepared to do)
my questions are-
if i do replace the "caps" will this improve the volume/quality issue.
are there any tests i can do myself (i have a multi meter) to check some of the other components ?
any help would be gratefully received
gaz
i have recently brought a second hand rotel RB-971 to replace my RB-850. i use the amp as a bridged mono to power a subwoofer. the RB-850 is 100 watts and the RB-971 is supposed to be 180 watts, the problem is that the RB-971 is no louder than the RB-850 and if anything has slightly worse sound quality.
i have read about replacing capacitors(which i am prepared to do)
my questions are-
if i do replace the "caps" will this improve the volume/quality issue.
are there any tests i can do myself (i have a multi meter) to check some of the other components ?
any help would be gratefully received
gaz
↧
would a PAM8403 amp board be any good for a portable BT speaker?
Just looking for a battery protection circuit to power something i'm currently working on and came across this all in 1 unit from the looks of it. I have no experience with 5v setups or PAM's as i have only used class D and T boardss to date.
5w+5w dual channel bluetooth audio stereo amplifier module pam8403 wireless bluetooth receiver support tf card dc 5v Sale - Banggood.com
Is this too good to be true?
5w+5w dual channel bluetooth audio stereo amplifier module pam8403 wireless bluetooth receiver support tf card dc 5v Sale - Banggood.com
Is this too good to be true?
↧
↧
Port output in hornresp
When looking at some different horn configurations I came to the realisation that hornresp doesnt lineairly model its port output and velocity.
When keeping internal volume and tuning equal in winISD there is no difference in port velocity or output, which is supported by the mathematics.
In hornresp this is a totally different story. I get drastically different (and not linear) differences in output, velocity AND port length when doubling port area, but keeping tuning equal (by also changing porth length). I also dont see a mathematical trend that explains it.
Anyone who knows what causes this? Do they also implement other factors to calculate the values? Maybe they also include port compression etc?
When keeping internal volume and tuning equal in winISD there is no difference in port velocity or output, which is supported by the mathematics.
In hornresp this is a totally different story. I get drastically different (and not linear) differences in output, velocity AND port length when doubling port area, but keeping tuning equal (by also changing porth length). I also dont see a mathematical trend that explains it.
Anyone who knows what causes this? Do they also implement other factors to calculate the values? Maybe they also include port compression etc?
↧
Audi A6 4F Avant oem DSP audo upgrade ideas.
Hello.
Sorry if this is discussed before, but the search did not show what I was looking.
I own a 2008 Audi A6 Avant with 10 way speaker audio system they call DSP. It is far better than the standard 4 spkrs, but inferior to the Bose option.
I am looking for ideas where to begin as I don't have an exact plan.
All I want is more power with OEM look and style.
The premium bose system has active feedback microphones installed in the car, a much better d/a converter, smps boosted chips and 13 speakers. So its a far better system overall, but a no go for me as this would mean a complete overhaul of my interiors.
I don't want to lay any extra cables, I hate removing/installing upholstery, panels etc.
As you may know, the audio in most german executive sedans of 2000s is routed via optical fiber from the headunit, cd changer, amp etc.
I have attached a photo of the amp.
The optic fiber signal is translated into analog, FL FR RL RR and 4x subwoofer signals.
The chips are both TDA 8595 with connected I2C bus. Any interaction with the output would throw an error in the system. The chips work @12V and are rated 4x45W RMS.
Can this amp be hacked? Just to get an 8ch analog output for an amp of my choice.
Speakers are another story.
Thank you for your patience.
Sorry if this is discussed before, but the search did not show what I was looking.
I own a 2008 Audi A6 Avant with 10 way speaker audio system they call DSP. It is far better than the standard 4 spkrs, but inferior to the Bose option.
I am looking for ideas where to begin as I don't have an exact plan.
All I want is more power with OEM look and style.
The premium bose system has active feedback microphones installed in the car, a much better d/a converter, smps boosted chips and 13 speakers. So its a far better system overall, but a no go for me as this would mean a complete overhaul of my interiors.
I don't want to lay any extra cables, I hate removing/installing upholstery, panels etc.
As you may know, the audio in most german executive sedans of 2000s is routed via optical fiber from the headunit, cd changer, amp etc.
I have attached a photo of the amp.
The optic fiber signal is translated into analog, FL FR RL RR and 4x subwoofer signals.
The chips are both TDA 8595 with connected I2C bus. Any interaction with the output would throw an error in the system. The chips work @12V and are rated 4x45W RMS.
Can this amp be hacked? Just to get an 8ch analog output for an amp of my choice.
Speakers are another story.
Thank you for your patience.
↧
I2s out Xilinx xc2c64a vq44
I have an unlabeled usb to i2s converter using this chip. Anyone know how to identify the correct output pins? I think pin 15 may be data out and 12-15 are the pins in question, but that is as far as I have got and I am not sure it is correct. Any insight would be appreciated before I embark on an annoying trial and error process.
↧
variable I/V resistor as volume control?
I need a way to attenuate the differential signals from op amp I/V, I would rather digital volume control but this is not possible.
A good quality, low tolerance stepped attenuator would be the only option for accurate attenuation of differential signals. The issue is that this I/V will also be used to drive HPs directly and I want output impedance as low possible.
The only way I can think of achieving this is using a rotary switch like those used for stepped attenuators to change the value of feedback I/V resistors and manipulate output voltage.
I also like that this will not add anything extra to the signal path, similar to a digital attenuator .
While this would be done in a way that keeps feedback paths from op amp output to inverting input as short as possible it feels iffy having them connected in such a way...
Is this generally safe or likely to cause issues?
DAC will be AD1862
I/V will be OPA1622
A good quality, low tolerance stepped attenuator would be the only option for accurate attenuation of differential signals. The issue is that this I/V will also be used to drive HPs directly and I want output impedance as low possible.
The only way I can think of achieving this is using a rotary switch like those used for stepped attenuators to change the value of feedback I/V resistors and manipulate output voltage.
I also like that this will not add anything extra to the signal path, similar to a digital attenuator .
While this would be done in a way that keeps feedback paths from op amp output to inverting input as short as possible it feels iffy having them connected in such a way...
Is this generally safe or likely to cause issues?
DAC will be AD1862
I/V will be OPA1622
↧
↧
Fuse for 300Va transformer and 6amp capable filter
So I'm building a power supply to replace the meanwell SMPS bricks sold with each ACA Kit. I've got a board capable of delivering 24 volt 6 amp and was advised to buy a 300 VA transformer with two 24volt secondaries to supply the board and ensure it can deliver the max current required by the board. I have bought IEC sockets with built in fuse holder and switch for 230volt mains. The fuse holders are empty.
What do I need to keep it all safe? Do pick an 8 amp slow blow fuse o allow a margin or 6 amp knowing you'll rarely use that much and it will be a momentary thing only. Fuse holder is for M205 type fuse.
Cheers
Steve
What do I need to keep it all safe? Do pick an 8 amp slow blow fuse o allow a margin or 6 amp knowing you'll rarely use that much and it will be a momentary thing only. Fuse holder is for M205 type fuse.
Cheers
Steve
↧
SLA1500 clone driver issue
Hi,anyone have a schematic of the SLA1500 driver card?I got a OEM clone here with intermittent issue on the High side drive.
For normal condition both High and Low output from the driver card is around 2.3V but once it got issue,the High side will output of around 4.4V something,which of course will turn on the 6N137(and proceeding BJT,which will turn on the MOSFET) and lead to high DC offset on the output.
All three 78M05 are working fine as measured,and also the symmetrical supply feeding the driver card OPAMP are fine too(got +11 something and -11 something all time).Swapping the driver card from a working unit WON'T help either.
Funny thing is the symptom is intermittent,sometimes is ok and sometimes is not.
Thanks in advance!
For normal condition both High and Low output from the driver card is around 2.3V but once it got issue,the High side will output of around 4.4V something,which of course will turn on the 6N137(and proceeding BJT,which will turn on the MOSFET) and lead to high DC offset on the output.
All three 78M05 are working fine as measured,and also the symmetrical supply feeding the driver card OPAMP are fine too(got +11 something and -11 something all time).Swapping the driver card from a working unit WON'T help either.
Funny thing is the symptom is intermittent,sometimes is ok and sometimes is not.
Thanks in advance!
↧
Simple shunt regulator issue
Hello,
I am building a shunt regulator and I have encountered an issue with it. Let me first give the proper information before I go into the details and the issue;
https://cdn.xingosoftware.com/audioxpress/images/fetch/dpr_1,w_765,h_574,c_fit/https%3A%2F%2Fwww.audioxpress.com%2Fassets%2Fuploa d%2Fimages%2F1%2F20180624192648_Figure3-WaagboShuntorNot.jpg
I am building the top regulator named 'Simple Shunt Regulator'. Since I wasn't able to source the 2sJ200/2sJ201, I have used the IRFP9240.
I am using a resistor as load (I tried values between 3 and 100 ohm ).
I am using a 5v1 Zener.
Before the regulator I have used a bridge rectification and a 3300uf cap.
When I am using the 27r and test the output voltage, I get 0.3V. When I changed the 27r to 5r1 I get 0.5v. It's a change, but obviously not what I have in mind. In both situations the resistor becomes pretty hot.
I imagine it could be the load being too weak, but I thought it would be good to have a few external eyes taking a peek on what I'm doing wrong. I am looking forward and obviously am thankful for external feedback on this issue.
I am building a shunt regulator and I have encountered an issue with it. Let me first give the proper information before I go into the details and the issue;
https://cdn.xingosoftware.com/audioxpress/images/fetch/dpr_1,w_765,h_574,c_fit/https%3A%2F%2Fwww.audioxpress.com%2Fassets%2Fuploa d%2Fimages%2F1%2F20180624192648_Figure3-WaagboShuntorNot.jpg
I am building the top regulator named 'Simple Shunt Regulator'. Since I wasn't able to source the 2sJ200/2sJ201, I have used the IRFP9240.
I am using a resistor as load (I tried values between 3 and 100 ohm ).
I am using a 5v1 Zener.
Before the regulator I have used a bridge rectification and a 3300uf cap.
When I am using the 27r and test the output voltage, I get 0.3V. When I changed the 27r to 5r1 I get 0.5v. It's a change, but obviously not what I have in mind. In both situations the resistor becomes pretty hot.
I imagine it could be the load being too weak, but I thought it would be good to have a few external eyes taking a peek on what I'm doing wrong. I am looking forward and obviously am thankful for external feedback on this issue.
↧