Hello, I’m a 23-year-old electrical engineering student. I found this site while working on my final project, and I believe it can be very helpful. I’m trying to create a wireless sound distribution system using lasers. The challenging part for me is that I promised my professor I would design the receiver and transmitter circuit boards myself. Any help would be greatly appreciated.

Hi Thanks for reading Two sealed back midrange drivers i am thinking of purchasing, the dayton audio RS52FN and RS52AN.
Do you know the differences between the two, have you heard them, or seen any information about them
How well do they perform against other sealed back mids at or about a similar price
What kind of crossover frequency would you use

At the weekend I went to the Audio Deluxe show in the UK and heard one of the most impressive systems I’ve ever heard. I’ve heard Kroma speakers on previous occasions and invariably been very impressed. The model in this system was this one: https://kromaatelier.com/jovita/
It uses 2 x Purifi 6.5 and 1 x 8” plus a Mundorf AMT. Despite using just one 8” woofer the bass was superb and went plenty deep enough for 2 channel hi fi.
The real surprise was the amp that they were using at least some of the time. it was a Swiss brand I’ve never previously heard of - this is it:https://tw.my-hiend.com/純淨透明的不凡氣質-瑞士orpheus-absolute綜合擴大機/

It was only later that I found this review and discovered it uses LM3886s. As the owner of some Neurochrome amps I know just how pur and transparent these can be when implemented well, and Orpheus certainly seem to have done that.

This combo produced truly awesome sound. I went back to the room 3 times and it was noticeable how long people were staying in the room to listen - much longer than is typical at such shows. I think I have only ever heard one other system that impressed me more and that featured the Vox Olympian speakers . . . .

I'm new to DIY audio, where should I start?
Maybe I could start with a headphone amp from a simple kit?

Hi all. I've come into possession of a 2016 VFET amp. It has worked perfectly while on test in my system. Last night however, I went to power it up, nothing. No blue LEDs no suggestion of power to anything. Almost like a fuse had gone... but if course, no fuse.

Which leads me to suspect the soft start circuit, or the traffo (a Toroidy). Ive tested the switch, because it was easy. Its fine.

I did not build this amp, but I know the person who did - sadly passed away - and his workmanship is super good. I am no expert but I can soldier, and solder away.. but I'm really keen to get your opinions on where I should start.. the soft start circuit is buried and will require a bit of strip down to test..

What's your gut thoughts? Thanks!

Hi All,

I recently acquired Monitor Audio B6 (bronze series) that has no crossover (for both).

I would like to build one same as the original.

Does anyone has a schematic design of the crossover / kind enough to be troubled by posting picture of the crossover in an original one?

I've tried to search with no luck.
The closest one I got is MA BR6 (bronze series that comes after B6) from youtube video disassembly - not sure whether it would be the same design and value.


Photo of the Monitor Audio B6 (come from google search)

,

Regards,

I was in a shopping mall the other day and in one store, the music sounded very good. Clear and articulate with nice bass. I normally don’t give a second thought to muzak playing from store speakers but these sounded different. They also played some interesting acoustical tracks with great dynamic range (usually dynamic range and ambient background store music don’t go hand in hand). I looked around and saw these 2 way MTM speakers on the wall every 10 feet or so. The store must have had 30 of them. I also saw some subwoofers installed hanging way up in the ceilings painted white so you don’t notice them.

These wall speakers had a unique 4 tweeter array in a crossed axis arrangement. I think that helps to give good angular dispersion. I took a photo and did a reverse image search and turned up a brand I never heard of. James Loudspeakers. Apparently, a 4in deep sealed cabinet and very high sensitivity but 4ohms. Just wondering if anyone has heard/seen these and if we have seen this tweeter array a somewhere else. I think a 3D printed housing and 4 smaller Nd dome tweeters could be made to DIY this approach. Certainly would increase power handling a lot.

I think this is an older model not currently made anymore as the latest from the James Speaker website has similar looking units but not the same. The one on the reverse image search said it was an OW63 which goes for $1500. Might be a neat tweeter design to DIY and do an MTM or even a regular TM speaker with wider dispersion.

According to my practical tests about inductor cores at 200khz switching of which is my best preference for class d amplifier, i noticed too much noise at (music pause) using a phone as audio source charger plugged in then thru a mixer to my class d prototype using sg3525 as signal generator & ir2110 & buffers as fets drivers. There's too much noise using t130-2 core carbonyl than when i changed to a blue aph33p60. Infact this blue core is absolutely quiet. Some things are better done practically than reading theories to actualize outcomes.

Hello DiyAudio community,

I’d like to propose an addition to the forum rules to help protect designers of printed circuit boards (PCBs) from having their work copied or repurposed without permission. I’ve been reflecting on a few situations I’ve seen in the community, and I think this could benefit us all by fostering respect for original design efforts while still encouraging collaboration and innovation.

For context: many of us spend significant time—sometimes 100+ hours—designing a PCB to share with the community. Typically, we organize group buys so members can purchase boards directly from the original designer/s. This process works great until someone takes that design, creates a near-identical variant, and presents it as their own work—often without credit or permission. Not only does this undermine the original designer’s or teams efforts, but it can also confuse the community about the origins of the design and dilute the value of the collaborative spirit we’re known for.

My suggestion is to add a rule along these lines:
“If a member creates a variant of an existing PCB design shared on the forum, they must (1) reference the original designer(s) and (2) obtain explicit permission from the original designer(s) before selling it or starting a thread about it on DiyAudio. This applies to designs that are substantially based on or derived from the original work.”

This wouldn’t stifle creativity—folks could still build on others’ ideas—but it would ensure transparency and respect for the time and skill invested by the original designer. I think it could also encourage more people to share their work, knowing their efforts are safeguarded.

I’d love to hear your thoughts! Have others run into this issue? Do you think this rule makes sense, or is there a better way to handle it? I’m open to refining the idea based on feedback.

Thanks for reading, Stuartmp

Hi im new around here !!
Have this Amp , came in protection !!
NOne mosfet burn or Bad .

Following Mute from Output drive card ,
Find a M6 transistor bad , replace it and the amp turn on !!

Testing the amp find out that output lowside mosfets are a little bit warm , putting signal in and speaker they gone more warm than usual , HIGHSIDE not they have normal temp.

Pullout output mosfets and test all drivers , follow waveform from drivecard to mosfets pads , its fine square.

When I load the output fets the waveform on gates of low side get distorted .
The Highside are ok completely square .
Any idea whats going wrong on it
Thanks







Low Side Gates loaded!.

Here are more pieces of a project that is not going to come to fruition.
For sale are Acoustic Elegance 10" (TD10S) woofers. I have two, 4 ohm (TD10S-4A) woofers and four, 8 ohm (TD10S-8A) woofers to sell.
The "A" denotes the Apollo upgrade which all woofers do have. All of the woofers have a black phase plug and not one driver was ever used.
The drivers were delivered 2 years ago. Located in Michigan.

I would love to get $1,000/pair and shipping will mostly likely be covered by me depending on specifics.

I am repairing a Denon AVR-5700 which appears to have suffered some sort of overload or short as there are a few resistors that are burnt/melted and capacitors that are popped/blown.
Tracing the circuit it appears that either the voltage spike came out of the MP1715 to damage the resistors/caps OR it went into the MP1715. (as I am not sure what happened to this unit picked it up cheap "not working" to repair)

I'm replacing the caps/resistor, but I also wanted to check the one MP1715 (and since they are typically paired with the MN1715 I should test it's pair)

I can't seem to find any sheet data on these...
Does anyone know what the E/B/C is on these two? And what sort of reading I should be getting across the pins?

Thanks!

Hi Folks,

I engaged an an AI online to see if I could get it ti design a Phone preamp. It then walked me through this layout on KiCad. Can somebody tell me if this looks like it would work? I'm pretty amaized. This is the left channel.

Tim

Hi Guys,

I'm stumped. Whenever I turn on the amp the ground thermistor starts to glow cherry red and the fuse blows.
Obviously, a lot of current is going to ground, but I have no idea what's causing this.
As far as I can see, I have assembled and connected the power supply properly.
So far, I can tell you that the transformer output voltages are 18.5VAC and 18.6VAC.
Has anybody had this problem, or does anybody see anything wrong?
Like I said, I'm stumped.

Thanks,
Dave Chorney

So these were my first speakers I ever built and they have done excellent duty as party boxes for a long time, over 20 years now but the foam surrounds on the drivers are starting to go and I need a cheap but effective Australian replacement driver.
The original are some Tandy drivers I got on clearance, sold [ mislabeled] as subwoofers but with an decent enough sound that The Boss still thinks they are one of the better efforts on my part. 32mm Voice coils and 6mm X-Max P2P
So around 200mm cutout and usable to 3k with the XO I have already which is first on the mids and a second on the tweeter.
I need a quad of them in 8R [ 7.6DCR] or close
The Faital Pro 8FE would work if I could afford them and there were enough available but a bit above my budget; ditto the locally made Lorantz Audio and the Eminence so I'm hoping somebody has something my Google-Fu hasn't found and the cheaper the better at this point

Hello everyone,
I'm Christoph from Germany and I've been building loudspeakers as a hobby for about 3 years.
I particularly enjoy comparing the speakers I build with each other and enjoying my music collection in different ways, because there is probably no such thing as the perfect speaker.
My hi-fi journey is only just beginning, so to speak, but I've already learned a lot about the technology involved and my own preferences.
I am looking forward to all the information I will find here.
In particular, without wanting to rush it, I already have a question for "planet10" about a construction plan 🙂

Best regards 🙂

ok long time member under old name and lost logins and all my data in flood so back on here and starting back in finishing several many yrs old on hold projects

1) Revel F36 blew my speaker budget for the year ( $1200/ pair, lol) and yes I have read , reread, all the reveiews , data , spinorama on all the revel/harman speakers I could find.
the only thaing that bugs me abotu the F 36 is that 4 k broadband hump, esp when compared to the F 35 and others that hit the target curve a bit better,
I have a very large room and high ceilings and sit about 13' away but that hump is still noticible, not enought to make me not love the seakers,But..

There has to be a easy way to DIY those factory crossovers to get rid of that hump. I know Revel had to cut costs somewhere.. I have seens some pics in a vid of the x.o
and it doesn't look like too many components and maybe even bi-polar caps>??

So anybody up for a project? I have Holm RTA REW a nice focusrite DA , calibrated mikes old 50mhz scope ,etc.

I'm thinking, just pull the board, put a R that matches the DCR of the tweet and measure it then work to get a shelf filter in and upgrade the parts while I am at it?

Few hundred$ would be worththe investment to really amke these beauties sing?

The marking is LA on top and 9A on bottom.

I'm working on a Audio Control LC-5.1300.

Hi all,

I have a pair of Purifi PTT4.0X08 and 4x SB16PFCR-00 6" Passive Radiators for sale. Price is $580 shipped in CONUS + PayPal fees. The drivers are brand new and never installed. Thank you.

The last period I played a lot with output stages. The last one which entertained me a lot was the Warbler which is a more advanced Mofo.
Initially the Warbler was used with 3.4r/88db bookshelf speakers and needed a lot of bias to give out something.
In the meantime the story with the speakers changed and I got something else that has a minimum impedance of 6r and and a lot more spl, 96db.
Now with these I started to really enjoy the Warbler but unfortunately(for me) another used wanted the modules so had to sell them.
So what to do now?
I was simulating since some time a Warbler with a front end and global feedback so it was time to put it on a pcb.

So this one doesn`t need a preamp in front of it.




Here you can see the modules assembled. The ones from the right are A2Cmx-V power supply filters and negative rail generators.
The amp requires a positive high current power supply and a negative low current one so the A2Cmx-V takes anywhere between 16-32Vdc on its input and gives ~3V less on the high current output and -30V on its negative output.


Here you can see the noise on the output of the amp when powered with laptop brick smps and A2Cmx-V


Initially I went for too much open loop gain and feedback that gave some ringing


The problem was solved by increasing R13



So now was time for some thd testing to see what I get.

With 2A bias you can get a bit more than 10W/8r at quite low thd


For 10wrms a 20v power supply is enough though a bigger power supply voltage will give better thd performance so I opted to do the testing at 29.5V

If you need more power then no problem, you can increase the bias to 3A which will get you 29W/8r which with the right speakers(like in my case) can bring down your roof.







If you don`t dissipate more than 40W you can use to247 devices instead the so227 like I used.

Here is a pic of the amp at work.

The inductor in the picture has 150mH/0.7dcr/4A but actually does 3.6A before starting to saturate. These were quite cheap when compared to hammond, I think half the price.
Depending on the needed power, a 2a/70mH choke is the minimum that can be used with this project, or at least this is what I seen when simulating. I have only these 150mH inductors for test.

If you listened to the Mofo you know already how nice and warm sounding it is, this amp comes close to it but at the same time it has much better control of the speaker.

I'm building the streamer using these instructions



However, all I need is a spdif out to the DAC.

I understand that I can use the TransportPiAES board instead of the HDMI board. But I'm trying to cut costs - can I use the TrasportPi MkII instead? The author mentioned it, but it looks like it's a different shape. Will it fit? Or what can I use for the spdif out with this configuration?

Thank you
Ken

I’ve spent my life using audio gear and servicing the mechanical side of turntables but since Covid forced early retirement I’ve become interested in learning more about the electronic side of things, so that’s why I am here.

Hey there!
I just became the owner of a very wonderful Threshold S/200 optical bias amplifier. It is in great shape, but clearly could use a tune up. I have either a very low hum or maybe a static noise, it's hard to tell. This is through 98db speakers, so they are a bit sensitive. This may just be a limit of the power supply, but I am ready to learn about this amp.

One major issue is the lack of a printed schematic or service manual. It would be extremely helpful for those who need to update their amp as things get out of spec.

Are there any capacitors that fit exactly where the the Mallory caps are? Diameter seems easy, height less so. If I just need to search, I can on Mouser and Digikey. Just hoping for an easy solution.

Is there really any point in replacing the tantalums? Depending on the schematic, they seem to be used just fine.

So far I was able to set cold bias and temp. Both of those readings are good.. Dc offset seems high. I should have recorded them, I will tomorrow.

I realize now that I must get many tests done tomorrow and update this post.

Hello everyone,

I'm an audio enthusiast with a deep passion for high-fidelity sound and DIY audio projects. My journey into the world of audio started with a love for music and evolved into an obsession with high-quality playback, digital-to-analog conversion, and building custom audio systems.

I have a particular interest in DACs, streamers, and high-resolution audio, especially working with ESS Sabre chips, Raspberry Pi-based streamers, and Ian Canada components. I'm always looking to optimize my setup, explore new technologies, and learn from the experiences of fellow audiophiles.

I'm here to share ideas, gain insights, and collaborate on projects that push the boundaries of sound quality. Looking forward to engaging with this amazing community!

Best regards,Riccardo

Hi all.

Originally I was looking to build a double 12" sealed woofer enclosure to go between my BMS 18n862 sealed subwoofers and, perhaps, multiple types of midrange and tweeter combos in a separate enclosure. But I got interested in passive cardioid enclosures after looking through several threads.

In my use case the requirement is 100hz to 300hz/500hz, but the wish is 80hz for low end extension. The specific dispersion goal I'm not fully sure about yet.

The options for woofers I shortlisted for the sealed version was: SB Acoustics SB34NRXL75-8 and Oberton 12NSW600, but after reading about the The Bitches Brew Open Baffle Live Edge Speakers by Perry Marshall I started to wonder if perhaps woofers optimized for open baffle use would make more sense in this case.


For the sake of a more general discussion though my question boils down this:
What would be considered an optimal woofer for a passive cardioid enclosure between a subwoofer and midrange?

Hi:

I am new to this forums here at DIYAUDIO, I found this site searching help for some issues I was having with speaker's crossovers.

Now, I have learn a lot from you all, it's been really nice, and this have encouraged me to experiment and learn more.

I recently purchased a XY LM3886 amplifier kit at eBay. It is composed of 2 amplifier boards and a regulated power supply unit. I have attached a picture of the actual kit I bought. I have not received it yet, but I want to know your opinions about this kit, and if there is anything to improve it.

I also purchased a ALPS potentiometer for it, I have seen that they also sell "speaker protection boards", do I need one of those?.

I also know I will need a transformer, I was thinking about a toroidal from Antek, the AS4222 22V 400VA, is this OK for this setup?.

Thank you very much.

Currently I have an original M&K MX105 (push-pull dual 12") running off a newer Dayton 250watt plate amp. My music system is in my mostly open basement (1000sqft). I would like to upgrade to dual subwoofers for better bass balance but am not sure what would be the best for my system. I have mostly fullrange-ish tower speakers, listen to all kinds of music fairly loud (mid 90s db avg) (mostly rock and classical, but honestly all genres). It's been really hard to find a used MX105 but I can find MX125s a bit more often (maybe just higher power handling but not sure what difference is). I was thinking of getting a used MX125, replace the plate amp to a matching Dayton 250watt or getting two SVS SB-1000 Pro subs (with dsp). I would have to sell a bunch of stuff (include the current M&K) in order to afford the SVS's.

Even though the M&Ks are much older and lack DSP, just one has two 12"s and a box more than twice as large as a single SVS SB-1000.
Would the SVS be comparable in output, midbass impact, etc?

I can afford about $600 now, but as mentioned, I would have to sell a bunch of stuff in order to get two SVSs. I prefer sealed box sound.

What do you think would be the best choice? Another 30 year old and slightly different M&K or two SVS's?

I was wondering if anybody had some kicking around they could trade or sell. I have four but need more.
Cheers.

Hello everyone.
I want to make a very low-noise linear power supply, 5 volts and up to 1 amp.
I've been thinking about integrated circuits like the LM78xx or LM317, but I'd rather put two or more in series to combine their ripple rejection and the low noise of both.
For example, an LM7812 followed by an LM7805.
Can the 70 dB ripple rejection of each be combined?
Just curious.
Regards.

I’m building a switch box to do A/B comparisons of two amplifiers as well as two preamps. I’m including a diagram of the relay contact assignments of the relays that handle the audio signals that I am routing through the device. The two selector relays (3 and 4) are turned on/off remotely from two different remote control units. At this point I have the preamp relays (4 and 5) wired up and switching properly from its remote unit. The signal path is correct and I am able to switch between two preamps, but there is a loud pop each time signal relay (5) turns on or off. Using a scope (without a preamp attached), I’ve measured the spike going into the RCA plugs of my device at the moment of the relay switching and it ranges from 50mv to just under 200mv and lasts 250-300ms. If these spikes indeed account for the popping noise they shouldn’t be enough to harm a speaker, but they are quite unpleasant.

I have 1N4148 flyback diodes across the 12v voltage input pins of the relay, but I’ve actually tested for the surge without the diodes and it is about the same. My best guess is that voltage from the switching pins is able to jump to the signal pins. I would have thought that they would be well isolated. I’ve tried installing .5uF caps across all the connections (power and signal) but hasn’t helped.

Is there any way to fix this problem?

Is the problem that 12v relays are too high powered for my application? I haven’t found any 5v 4PDT relays in the format that I’m using now. Low power relays signal relays could potentially work, but that would completely change the design and scope of the project. Or is there something else that I could do to supress the pop?

I’m attaching a diagram showing how I configured the relays and a couple of photos of my build so far. I’m really a beginner with this stuff, so please please excuse any shortcomings. I welcome any advice you might have regarding anything in this design since I dreamed this up on my own. Thanks, in advance, for your help!

--Jonathan

Hello everyone,

I’ve recently started a company focused on high-impact house parties and drum & bass rave events. With a background in software engineering and a love for system design, I’ve been diving deep into live sound, especially subwoofers, and I’ve come up with a novel solution I’d love to share and get feedback on.

For my last event, I built and deployed a 20 Hz tuned tapped horn to deliver deep sub energy from 20 to 50 Hz. As you probably know, tapped horns are monsters when it comes to efficiency and SPL per watt. But they come with a tradeoff: they lack transient clarity and can sound sluggish or boomy compared to sealed or front-loaded designs.

That’s where my idea comes in.

I’ve thought about a modular correction system that adds a small secondary driver into the horn path, which is fed a predictive, DSP-shaped signal designed to:

• Sharpen transients
• Cancel low-end ringing
• And tighten up timing below 60 Hz — without sacrificing the tapped horn’s natural output

The correction driver acts more like a subwoofer tweeter injecting carefully timed bursts or phase-inverted pulses to clean up decay and enhance punch. Think: servo sub tightness inside a horn-loaded monster. The driver will be smaller with a smaller MMS.

It will be DSP-driven, with a signal split and tuned either manually or with a convolution-based predictive model. Long term, I want to open this up to the community, make it modular, and maybe even build AI-driven tuning tools to match different horn alignments.

Would love to hear your thoughts — has anyone tried anything similar? Interested in collaborating on testing or refining the idea?

Thanks!

I am currently in the process of building my Mechano23 speakers.
So far everything has been going decently smooth. However, before entirely sealing the box I wanted to test the crossovers.

When testing the speakers everything was working fine. However, with the the box sealed using clamps and the crossover attached to the box. I noticed the tweeter started making a cracking noise when playing at higher volumes. After some re-adjustments of the joints I noticed the mid woofer was doing the same and the cracking in the tweeter had almost entirely stopped. After some thinking I presume that the issue is caused by a combination of bad joints on my crossover and internal vibrations.

The attached image was taken before the entire circuit was soldered. But for all the joints I twisted and then soldered the wires.

Could anyone provide some tips or help on how others have tackled this issue? I want these speakers to last a long time, so I want to make sure I do it right.

Thanks for the help!

Hello there everyone,
I have never installed or used software for drawing electronic circuits.
For an upcoming - simple amplifier project, I am going to need to learn & use circuit drawing software > to present the project to the DIY community.
I would be very grateful for any recommendations or advice regarding this.
Thanks in advance,
Mark

Hey people,

did some of you made experiences with the B&C 10MBX64 10" Driver? I like the exceptional efficiency eta_zero=3% in the 16 ohm version.

FS: TKD Stereo 50K Linear Taper Potentiometers PRICE DROP!

I have a few TKD potentiometers available. All of them are dual linear taper 50K resistance made with conductive plastic. These have been installed once, but never used. Pricing is $60 for the 2CP-2500 (25mm size) type and $25 for the 2CP-601 (16mm size) type.

As of 04/02/2025:
QTY: 17pcs 2CP-601 50k
https://www.tkd-corp.com/en/products/pot/cp600p-spec.html

QTY: 1pcs 2CP2500-P
https://www.tkd-corp.com/en/products/pot/cp2500p-spec.html

Shipping in the USA is $5 via USPS and outside of the US will be rated based upon location.

Selling 1x pair of very nice sounding Unitran 7U21 SE Output transformers

5K/7K Primary (60/45ma gap)
2,5 - 5- 8 Secondary
6W Output

Taking offers, will ship worldwide

New version of the Universal PreAmp arrived. I've had these on Ebay for years under HVFORLESS. I took down my listing during COVID for personal reasons. Then I noticed a project that kicked up in my absense. A few folks here reversed my board and added a few features. I would have loved to be in on that, but I noticed the thread too late. There were good ideas there. I took a few of those and added some of my own. 100 boards are already in hand, so any good feedback won't show up until the next revision.

• Octal socket on the board for optional tube rectification!! Options on board are now full wave, center tap, or tube.
• HV and LV ground planes.
• Grounded heatsinks for safety and heat dispersion (must use an insulator pad).
• Vent holes where needed.
• Gate resistor in Miada circuit (allows for MOSFET if preferred).
• Additional pads and larger diameters for electrolytic caps to accommodate multiple options.
• Trimmer resistors and jumper moved to more accessable locations.
• Fully scrubbed BOM with alternates listed for most components. Cost reduced with highly available parts.
• Optimized layout. Routing on top side with few exceptions, and no VIAs.
• Same 4" X 6.25" footprint and 2 ounce copper.
• Trace widths optimized for worst case currents with at least 50% safety factor.
• Spacing and isolation optimized for worst case voltage differentials.

https://www.ebay.com/itm/146473988873

Greetings DIY Audio forum; I've been in DIY and audio for a long time; nearly a 15 year career in live sound; DIY eurorack synthesizer builds of others design and aspirations to put together original designs eventually. I originally learned I was into all this apprenticing for an old hammond organ/original synth repairman; and have a passion for that original analog circuitry and resulting sound. Also Tape. Tape stuff is really cool. My biggest problems are usually finding enough time; the patience for surface mount soldering (when required) and some of those "well I never had to think about that - rats, wish I'd have known" kind of situations - which will probably be a decent amount of my posts here - the idiot checks and asking for input on how to improve a design before I go stubbing my toes over it. Can't wait to make more cool stuff!

Hi everyone! I'm an old professional woodwind player who loves audio. I do semi-pro sound and recording. I have 4430 JBL Studio Monitors, JBL mains, Mackie 450s, Marantz 2252B, Soundcraft Ui24, Tannoy bookshelf, assorted microphones, etc. In the 80s, based on jbl literature, I designed and built a high-frequency box containing two jbl 2105 and a 2405. I'm using a 3106, 8khz crossover for the 2405 and an aftermarket 500hz crossover for the bottom. I came here for advice on rebuilding the high frequency boxes. I plan to couple it with JBL 4430 which has a 2235 15" woofer. It has the sweetest bass I've ever heard.

Hello everyone, I came here looking for tips or ideas for fun electronics. I'm a fan of anything that runs on electricity, including appliances, computers, cars, and industrial controls.
Greetings from Mexico

Howdy gang,
Not quite sure of the words to describe my issue but I’ll do my best. I’ve also attached A Video Here which shows the problem in action.

The Cd player has been in my dads loft for over 20 years at least. We switched it on and when we tried to open the tray there was a jittering mechanical sound and it didn’t open at all. The belts were disintegrated so we replaced them, now the tray opens and closes smoothly. But when it closes fully, the jittering happens again.

Not sure why it’s happening.
The little switch that the end of the white plastic thing pushes when it closes does work, as if we trigger it with a toothpick before it starts moving, that part doesn’t move.

Little bit hard to describe but the video should help.

Any advice or ideas would be super appreciated as we’re at a bit of a loss of what to do next.

FS: Complete Drivers and original crossover to build the Dynaudio Finale speaker kit. I was saving this kit for build this great speaker, but frankly I won<t have the time, neither the space to use them, so my lost is your luck. This kit is long gone, impossible to obtain, I bought the drivers and the original Dynaudio Crossover over a period of 5 years, way back then.

READ CAREFULLY: Both the woofers and the passive radiators had their original foam surround destroyed, but was able to source the original Dynaudio replacement rubber surrounds. I had both woofers reconed by a professional in Montreal, using these rubber surrounds, so both are back in perfect condition, BUT>>> Both passive radiators still have their damaged foam surround, and need to be reconed. I have the replacement rubber surround, still in their original packaging, and it is quite easy to replace the surround since their is no voice coil to carefully align on passive radiator. SO YOU<LL HAVE TO DO IT yourself, (DIY you remembered 😉

So the kit contains all the drivers, in the original Dynaudio packaging, drivers where never installed, were stored in perfect condition, and boxes where rotated over the years to prevent any damage to the suspension. Drivers are virtually new (except for the passive radiator surrounds...) READ>>> What is missing are the <Variovent> ports, as listed in the kit documentation. I asked Solen in Montreal and they said it is quite easy to build using a simple round plastic ventilation vent, and add a few sheets of loose absorbent material, such as the losse felt inside speakers. It is just a loose restrictive port, such as a normal port stuffed with loose foam. Quite easy to build...
See discussion here: https://www.diyaudio.com/community/threads/closed-box-vs-aperiodic-box-variovent-dynaudio.408624

Kit Contains:
-2X Dynaudio Esotec D-260 tweeters
-2X Dynaudio D52AF Dome mids
-2X Dynaudio MW150 Mid-Woofers
-2X Dynaudio 30W100 XL, 4 ohms woofers
-2X Dynaudio 30W100 SL passive radiators
-2X Dynaudio original rubber surrounds, to repair both passive radiators
-2X Dynaudio Finale Crossovers, assembled
-Kit documentation kit enclosure drawings, etc...
Not included Dynaudio Variovent ports

I have tons on pictures, showing all drivers, I posted here only a few to show you how nice they are.

So you just need to build the enclosure, recon the passive radiators, and you"ll have a pair of great Dynaudio speakers costing easily 5k$ and more!

Shipping is possible, and would need to be done in probably 2-3 separate boxes (I already have the boxes). Local pickup in the Montreal area is also possible.

Asking 700U$ or 1000$ CAN, plus shipping (and 3.5% Paypal fee if outside of Canada), within Canada EMT bank transfer (no fee) or cash in person accepted.

This price is way under what I paid, just the crossover pair was 200U$ at the time, on ebay

Thanks for looking
SB

Hey guys, I just started planning my first DIY speaker build, so I'm a complete beginner. To keep things easy I want to build a little active desk speaker with a full range driver. It's supposed to be a standalone speaker without a subwoofer. I'm also aware that I won't get a lot of bass from such a little speaker. I'm already set on a 2.8 liter housing as well as the amplifier (Acrylic Up2Stream amp). The only thing I'm not really sure about is which driver to choose and whether to go closed or ported.

For the drivers I'm considering one of the following but I'm also open to other suggestions:

• Markaudio Alpair 5.3
• Tang Band W3-2141
• Dayton RS100-8
• Dayton PS95-8

Which one would you recommend?
Thanks a lot, appreciate the help 🙂

I have various items of hifi separates dating back to a Dynaco valve amplifier from the 60's. I try to keep them working and need assistance sometimes, hence my appearance here. The detailed technical knowledge available on the forum will mostly be beyond me but simpler questions do come up........
Terry

Sorry removed

Hello everyone.

I started making sound systems in 2019.
Last year I installed a CNC and are making speakers in 3D CAD using fusion360.

I feel that here is at the cutting edge of sound system research.
I am very much looking forward to reading your productions and discussions.
I would be happy to contribute to the accumulation of knowledge, even if in a small way.
Best regards.

Here we have an AU217 old model that in one case shows approximate voltages to expect during service which is not shown on service manual. As a former Sansui Authorised Service Center (1980~1990 steel city PA) I sort of remember some of the amplifiers service bulletin. This Amp used a 2SD188 and 2SB545 complementaries for outputs. Sansui used 2SD358 and 2SD528 as drivers. While it works, a service technician could substitute drivers by 2SA and 2SC type drivers.
Voltage reading at each transistor point approximately are as follows. Notice that I have used three 1N4149 type diodes as opposed to two 1N4148 often mentioned in various forum. Remember this Amp uses two DC rectifiers from the same AC source. For this design simplicity I have connected the Voltage Amp and output section to relay on the same DC power source. This unit has no DC offset pot but can be trimmed using R13.

What is you could not find the 2SB545 version or the 2SD188.
In this case you can easily modify the amplifier to use either NPN or PNP outputs only. You just need to rearrange a couple of components. See example below. I have done this for years, especially amplifiers that are heavily used in production, field music shows such as Bluegrass festival.
Here is an Example: -

All componet values are the same except I changed Q6 to 2SD188. Notice where I placed R41. It is now connected to the collector side of Q15. Q6 emitter and collector connection wires have to be reverces as well. That is it!

The structural diagram of the dual-channel 200W PWM DAC with ADAU1452 chip is shown below.



The board looks like this.



Measurement results, R load=4R, Vcc=48V.





Performance parameter PWM DAC:

• Output power: 200 W per channel, with a 48 V supply and R load = 4 Ohms.
• Speaker impedance: 2 - 8 Ohm
• Frequency response: 20Hz - 20kHz
• THD: less than 0.005% on 8Ohm load, and less than 0.008% on 4Ohm load
• SNR: 105dB(A)
• Spdif Input : 16-32bit 44.1-96kHz
• Spdif Output : 16-32bit 44.1-96kHz
• I2S Input : 16-32bit 44.1-192kHz
• Power supply: DC 12V - 48V/ 5A-15A
• Consumption power: Idle mode 16W, sleeping mode 2.5W
• Efficiency - 83%

The board in idle mode consumes 16W, which requires the use of a radiator with an effective area of 400 square centimeters. It is not recommended to supply 48V to the board without an additional radiator.

The price of one board is 95 US dollars.

Shipping at my expense.

Only two boards are available.

A starter project for Sigma Studio is attached to the message.

First off, I should start with a disclaimer saying THIS IS MY SECOND DIY PROJECT!

I am most certainly aware that this forum is full of much more knowledgeable, experienced folks, and I guess that this is exactly the reason why I am even posting this thread.

So, after this far too long prologue, let's dive right into it.

I have been lucky enough to get my hands on a couple of JBL 2206H drivers and an Eighteen Sound HD2000. A friend of mine owns a sound system, and these drivers were once part of two PA loudspeakers that are no longer in use.

The idea for this project is designing a new enclosure—one that would house the JBLs with a ported baffle, the HD2000 mounted freely on top, and a folded 15-inch subwoofer. ATM im looking at any subwoofer i could find aroung 120$ a piece (I'm on a low budget for this project)

I am looking for any tips, subwoofer suggestions that are budget-friendly, and anyone with experience who would love to give me good advice, etc.

Hi all!

I thought I'll do a quick write up on what I've found out the other day - programming the CSR8675!

The CSR bluetooth chips are the most well known BT modules out there on small china amplifiers. Although the Chinese are outsourcing for a cheaper chip, the CSR BT modules is still a much better option when it comes to changing parimeters or eq. Some CSR versions even have a test app where you can change some eq settings on the fly! (Only known to work for CSRA642xxx and CSR867x).

The reason why I'm doing this write up is because I've struggeled to get the CSR8675 modules to be programmed by any software. This is because both the software and the firmware on the modules have to match to work, and they often don't! I've also spent tons of time trying to find the most up to date version of the ADK, but had no luck in fining an ADK that matched the firmware on the BT receiver I had. Then I came across TinySine and they write up on their BT 5.0 modules/amplifiers. They also use the CSR8675, and was kind enough to send me the firmware for their products. This made it possible to flash the module with a firmware that would work with the ADK they had posted on their site.

Just to give some pros and cons on the CSR8675 modules:

• Transmitter and receiver mode, up to 100x(?) can be liked together, not just TWS where it only supports 2 connections.
• More feature for DSP in the CVC software, including crossover and dynamic bass adjustment (key point for me, still testing it)
• 3 analog outputs (L, R, SUB)
• Working audio prompts (.wav files to be played on events, not just beeps)
• APTX-DH

• Some issues with connecting to the programmer, needs to be reset by PS tools to properly connect sometimes
• New software, no other writes up on it

So lets begin. First off, go to TinySine's web page and read up, that will give you a jump start on what I'm taking about. I would also recommend to just go for the CSR64215 if you don't need the advance DSP settings or multi connection. The CSR64215 can do EQ, TWS and APTX and is much more stable to program and use. There's also some amplifiers you can buy on ali that uses the CSR64215:

My fav CSR64215 amp combo:

• The new TWS has a bluetooth hifi amplifier for bluetooth CSR4.2 amplifier|tws| - AliExpress

Note: even got a working AUX input that is routed through the CSR chip, so you get seemless switching between line-in and BT. You're EQ/DSP settings also work when you route it through the CSR chip! Also got connectors for LED, BTN etc. I love using the LED on a BT switch for my speakers, you can create cool patterns to let you know what's going on.

More generic, and a little cheaper:

• CSRA64215 Bluetooth 4.2 4.0 POWER Amplifier board TPA3118 30W+30W AMP APTXLL NE5532 With call function for 12V 24v car-in Replacement Parts & Accessories from Consumer Electronics on AliExpress

Note: does not have AUX in, nor breakout for an LED.

I do not recomend to go for neither the CSR8630,-35 or -45 unless you don't care for changing anything. You can do it, but they do brick easily. It is possible to get them to work if you brick em, but just don't...

Quick tip:
If you only want to change the name, you can use a generic USB SPI FTDI programmer and use PS tools to change the name. Take a look here for more info. For any other changes, you do need a dedicated USB to SPI adapter from CSR.

Info to get you started

Change Name:

• Change Bluetooth Audio Amplifier Name or Audio Tone

EQ settings:
https://www.tinyosshop.com/index.php?route=information/news&news_id=86

Restore for older versions: (8635,-45, A6215)
https://www.tinyosshop.com/how-to-restore-bluetooth-audio-module-default-settings

For other great CSR info in video format, visit Darie on YouTube, a great friend and CSR-BT master!
------------------------------------------------------------------------------------------------------------------

Now, to get going you will need a receiver. There are some other breakouts and they will work, you just might need to change some of the PIO's. Also, you WILL need a x64 bit version of win to get the software to work properly, I've tested it with win10.

Firstly, go and download the tool at TinySine, the ADK 4.3 is all you need. You can also fin the software in my dropbox folder along with a lot of other info regarding CSR, both software and a ton of documentation. It's kind of messy, and I will add more of the CSR stuff I got laying around.

Dropbox heaven for CSR

EDIT 18.02.21:
Google Drive folder

Secondly, to be able to do some changes you need to connect the programmer to the module, there's kind of a "standard" layout on most BT amplifiers/breakouts for SPI.

G -GND
V -VCC (3v3)
E (blank) - SPI enable (connect it to 1v8 or with a resistor to 3v3)
I - MOSI
K - CLK
B - CSB
O - MISO

Next is to burn the correct firmware on to your BT module. This will make the module exactly identical to the TSA6175 that TinySine is selling. One thing to note is that you need to do some changes if you're doing to to this to several modules. The main issue with copy-paste the firmware is that every BT module has the same address and is identifies as the same device. This is not a good thing. I will explain how to fix this after you have burned the new firmware:

Find the folder called "8675_firmware" and copy it. You will then need to open "BlueFlash". Connect the module to the SPI and the software should prompt the SPI converter. Click on "Stop Processor" if your BT module is running. When the module has stoped, find the folder with the firmware and click on the "dump" file. Clock on download, and the software should do the rest. Your module is now updated and you should be able to use the "ADK Configuration Tool" to change buttons and the general behaviour of the module!


To test if everything went well you should be able to connect to the BT module we just updated. To do this on this module you will use a wire between "KEYCOM" and "vol-". First turn the module on, you should hear a sound. Double tap the "vol-" with the wire and you should hear "pairing". If not, use the wire to single tap KEYCOM and "NEXT" then do the "vol-" double tap. This will set the module in receive mode and in pairing mode. If you tap the "PREV" you will go into transmitting mode. I've not tested anything else at this point than receive mode. "The name will be "CSR6875" if you got it into pairing.
To change the name or any DSP settings follow the guides at TinySine that was given above.

Last part in this tiny guide is to pull up the "ADK Configuration Tool". Here you can use it to change mot of the setting. Be warned, some settings can cause if to not work properly, but no worry, if everything goes south, you can always reflash the firmware and you're on safe ground. Try to stay away from most of the settings except the once in "User Interface" that seems to be the most safe. Also DON'T delete all the settings under "User Events" etc, leave at least one if not you WILL brick it!

Have fun, and let me know if this was helpful. I would recommend watching YouTube videos and read up on things before you mess up. You should be able to fix a bricked module, but it can be a pain. Just ask questions if something was unclear, and I'll try to explain it. Do take a look in the Dropbox folder, as it contains a lot of info and some pictures.

I have the title receiver and try to adjust idle.The one channel stay solid on my adjustments but the other fluctuating up and down +/ - 3-4 mv and it is not stable.I have sprayed all 4 pots with teslanol and turn few times to clean up. What causes this? Have anybody experience the same problem?The stable channel have repaired with other transistors from previous owner and the unstable channel have the original marantz transistors.The supply is the same volts on both channels. And second problem when volume pot is full down i still heard music on speakers.I read in other forum the volume pot do some problems.Thanks for any help.

Greetings, been a while since I posted.

Still pondering about triode grid current limiting and the resulting plate wave form negative swing limit, I decided to try to match up Merlin's Fig. 1.20 in his excellent book "Designing Tube Preamps for Guitar and Bass" with my PSpice simulation using the Ayumi and Wayne Clay (curve captor) 12AX7A spice models. I have overlaid the two scope shots as best I could. Not perfect but good enough to see that the lower limits differ quite a bit. If there is any merit to my method, then the SPICE model limits at about 88V, while Merlin's test scope shot indicates the lower limit is close to 120V. Is either voltage realistic?

I asked ChatGPT o1 to deep think about this and present the commonly-reported lower limits it could find, and it came up with 40-60V (Rp=100k, Rk=1k5).

See the attached overlay (@Merlinb, hopefully you are ok with me posting this publicly-available scope shot from your book).

Hi
I've seen this board is used in many cheap streamers.
According to this it has fixed i2s output:
UP2STREAM Receiver Module DLNA AirPlay Wifi Multiroom Analog and I2S - Audiophonics
I'm don't know allot about i2s but does that mean you could wire up those cheap RPi dac hat boards or would you need a clock?
Has anyone wired an external dac to these as I haven't seen anything on searching.
I'm looking for a more reliable Spotify connect streamer than my rpi and volumio.

Just like the title says. How far did you go and what caused worthwhile differences?

All changes were by listening and checking with an oscilloscope as I don’t have any other equipment anymore. I could not detect a noticable improvement between buspower or external power with one of those popular phone chargers (SMPS).

Then I removed the best battery system so both diodes. That means this one no longer has buspower. Replacing the external power series diode for wire made the DAC getting 5V instead of 4.7V. This together with a linear 5V PSU connected via the Lemo connector made the most significant improvement till now. Power is clearly cleaner.

Replacing the original unmarked opamp for OPA1642 resulted in a small but noticable improvement.

Good evening, with this post I wanted to share my journey on restoring and then modding a broken MPA1004 amplifier (16 mosfets, 2SK1058/2SJ162) that I got for spare parts at the price of 40 euros.
It was FILTHY. Full of hair, dust, it was probably running in a basement somewhere. Also all the mount brackets for the mosfets were missing, capacitors bulging, lid missing as well.
I had to literally wash the board with degreaser and water (after removing most of the components) and then in isopropyl alcohol.
(the board in the picture on the right has different color because I also did the procedure on two more of the same amps, but it's equivalent)

Then I took the heatsink and drilled and threaded all the 16 holes for the mosfets to have better thermal contact (and because I had no brackets)
Mounted the components, new capacitors, replaced all the driver transistors because they were out of specs and rusted, replaced the op amps

Could not find any NE5517 so I improvised making an adapter from the SMD LM13700. Then replaced all the potentiometers because they were heavily oxidized.

The amplifier is now perfectly working, I used the Hitachi Application Note as a reference for setting the bias current because the circuit is more or less the same. I was lucky none of the mosfets were broken.

This amplifier is currently in use in my living room connected to the Onkyo TX-SR505E 7.1 Audio receiver to power this giant one meter wide subwoofer I built here and have movie nights with friends and family.

Hey eveyrone, i want to get a TS3031 (QCC3031) and tinyshine said its a receiver by default but i can program it to be a transmitter. How hard would it be to make this into a transmitter? Its going to get the audio from a 3.5mm from an iPod. Im completely new to this bluetooth stuff so any help is appreciated.

A lightly used pair of 2.7uF 1000V Mundorf MCAP Supreme Silver Oil Capacitors removed from my tube preamp.

SOLD

I'm curious about this phono preamp design, and wonder if anyone can do a 'spice' investigation of its design.
Namely to find out it's accuracy (%) at adhering to the standard RIAA curve.
And what a common 3.5mV cartridge would be amplifed to a final level after the Emitter follower 'booster' transistor.

The goal: make something that could shake the entire house, walls and floor, with good enough sound quality.

3 years ago I bought a subwoofer from a local shop, a 12 inches JBL Stage 122D, 250W RMS and 1000W peak, for a very good price. Good specs, sensitivity etc..
I had no way to use it at the time because I needed a proper enclosure but at some point I just realized I could use a simple yet effective to make a subwoofer without having to research anything super fancy or extraordinary.
Designed a ported box with a volume of 60 liters, tuning frequency of 28Hz and wide and narrow enough to fit in my living room.

For the wood I used 28mm thick planks, then cut everything to specs and made the hole with a jigsaw. Planks are held together by screws and wood glue, it doesn't go anywhere.
Then applied several coats of varnish, sanded and painted again to have a nice glossy finish.

Inside I put the usual foam, mounted input connectors (one for each coil), mounted the subwoofer and closed everything.

The finished subwoofer box is as wide as my kitchen table.

The result is quite amazing, even at low power all the windows of the house start to vibrate.
Turning up the volume a little bit will also make the floor and walls to vibrate, causing the furniture to shake and producing the same result as a low magnitude earthquake.

Was It a success? Well, I never had so many guests in my house for movie and music nights like I have now.
After some testing I ended up using this 1000w Mosfet Amplifier I repaired and showed in this article to power the subwoofer and connect it to the existing 7.1 audio system of the living room and the TV.
With that amplifier and this subwoofer I can feel frequencies down to 10Hz (not really hearing them, but you can feel them on your chest). Impressive.

DISCLAIMER: no chihuahuas were harmed during the production of this subwoofer. The fact that the neighbors were willing to let a dog bark indoor for half a day was enough to make me stop caring about annoying them too much xD.

For sale, a pair of large speakers, I built, around three years ago. These haven’t seen much use, probably between 2 to 300 hours. They have passive crossovers built-in, I originally use them with an active set up but passive is easier to just plug and play. I used only Jantzen coils and caps, they are all nice quality, also resistors from jantzen.

sound great on everything from my single ended KT88 amp to my hypex stuff, very sensitive, and the waveguide is a gem. Patrick Bateman said it was literally the best measuring waveguide he’d ever seen. It’s built like a tank, nice and solid, and I have damped the back with bitumen pads.

The speakers are built from 18 mm Baltic birch, with Neutrik speak-on connectors. An internal brace supports the magnet for the waveguide so there’s no stress on the waveguide itself.

Basically, these sound fantastic, but we have a new baby, a 2 1/2 year-old, an 11-year-old, and there’s no way these will survive in the living room. I’ve had them stored away in an extra bedroom for the last two years, it’s a shame for them to just sit.

I would truly hate to have to break these up, but I will if I have to....

I’m located about 45 minutes outside of Vienna.

Feel free to get in touch If you wanna audition them.

These need to find a good home.

1200 euros

I'm selling a pair of Focal Audiom 15 WX drivers, which are used but in perfect condition. I no longer have the original packaging, but I can assure you they will be packed securely. If needed, I can provide photos of the packaging process for your approval. You can find the technical specifications in the following link:Datasheet

The price is fixed at €1500 for the pair, payable via bank transfer. Shipping costs will be the responsibility of the buyer. I'm not interested in any material exchanges. Please feel free to reach out privately if you're interested.

Some background.
The project it is to power...
https://www.diyaudio.com/community/threads/diy-front-end-2022.394339/
The supply board..
https://www.diyaudio.com/community/...4-tl072-regulator-based-on-studer-900.297610/

The transformer..
(Probably total overkill but I own it and can't afford any other) A Muuntosahko-Trafox TAE-160. 230v in 2x22v out. (one rated 2amp the other 5amp) 160VA
Seems this Finnish manufacturer makes high spec Transformers for industry and medical.

The Transformer and associated parts include a large 'Prefilter" that I am assuming is the industrial version of the noise filter found on many consumer items chassis mount ac input. Yes/No ?

In addition to the input and output wires the transformer has a transparent input wire that is coupled to the ac input cable earth. It is labelled S and SP. What does this connect to/do within the transformer ?.

The mains ac cable goes from the Prefilter to the switch. Both P & N are switched with the N going to the transformer but the P going to Power Resistor in series with the transformer. 7.5R @ 25W.
Why ? What does this do ? Can I omit it in my build ?

Finally, I've seen comments that a too big transformer can be as problematic as too small but never any explanation for this. Is it a real thing ?

Void Trinity X

Recently heard 8 of those subs and was very impressed how clean they are and amount of SPL they put out.

Anyone have any more info about those? Very limited info available regarding cabinet design with quick search on web

I picked up a pair of JBL JRX115's as a project. One is good, the other has blown drivers. Looking to learn, I bought a UMM-6 microphone, a Dayton Audio Odeum 15N woofer, and a JBL Selenium D220Ti compression driver. Installed REW and measured the new drivers individually, installed in the enclosure.

My measurements, especially with the CD, seem to roll off much faster than the curve in the specs of the Selenium D220Ti. This is even more evident when putting my measured readings into an FRD file and load it into VituixCAD to work on the crossover. I can get the response graph looking pretty flat, but I am concerned that this is without a resistor on the CD. Should I still add a resistor and let the high frequencies taper off, or run it without a resistor?

I also measured the working box with the stock drivers and found that the curve is not flat and tapers off in the high frequencies. I dont want the highs to get out of hand in a PA setting, so maybe adding a resistor to taper it off is the way to go? Looking for suggestions. Thanks!

PS: While gathering the factory response graphs for the D220Ti, I realized that the flat response is the one in an Anechoic chamber. The plane wave tube graph looks a lot more like mine. Maybe that is the difference.

Has anybody to sell
1pcs of sony 2sj18 i think rank 5 for Sony TA-F7NB?
Thank you for any help to find one.

Hello,

I came across this forum while looking for information about the LinearX Leap 5 software for my dad. After doing some research, I found a way to make it work on 64bit Windows versions (Tested on Win 10 64bits, Win 7 32/64bits and Win XP). I noticed that some people here have asked about it years ago, so I’d like to share it with everyone.

Participation for this group buy is welcome for this line level preamplifier with defeatable tone controls. The stereo preamplifier with power supply will come to about $160.
You will need to attach a transformer, quality knobs and a chassis. Enjoy

Hello everyone,

I'm new to posting, but I've been lurking these forums for a couple of years now. I first got into speaker design in late 2022. I was looking into upgrading the sound system of my truck, which led me to DIYMobileAudio. With how much of an acoustic mess an automotive cabin is, I decided to learn how to design crossovers/loudspeakers for home hi-fi use first, which led me here. Funnily enough, I've yet to finish the truck project.

Prior to all this, I spent many years playing drums, soldering DIY eurorack modular synths, restoring vintage recording gear and studying room acoustics to improve my home studio space. Even took a few audio recording classes in college during my first stint. I returned a year ago to study electrical engineering. So... I've spent a good amount of time in audio DIY spaces, but I hadn't actually attempted to build loudspeakers until a couple years ago.

Built a few single driver full range units in the beginning. They sounded alright, but I had a lot to learn. Built a few of XRK's foam core designs. Lots of "give this a try... something is missing... back to studying theory". It's a ton of fun amidst the headaches 🙂

At the moment I've been dialing in a 3-way design using one of Augerpro's 6.5" elliptical waveguides and an SB17NBAC35-4. Also, a 2-way with one of Mabat's ATH horns.

Happy to be here with all of you to further the progression of DIY audio projects and talk shop! Cheers

Hello, I am new here and looking forward to learning more!

Selling the following individual mostly 8" mostly 8 ohm variants mostly midwoofer and full range range drivers. All are new, most include original boxes and packing material. $20 domestic shipping flat rate. Please inquire if interested:

-18Sound 10MB400 -- $80
-Celestion CF0820M -- $40
-Faital Pro 6PR160 -- $40
-Faital Pro 8PR210 -- $60
-Jensen Tornado Classic 100 12" -- $80
-Oberton 6NM150 -- $30
-PHL 2530 -- $60
-Seas L26RO4Y 4 Layer VC Version -- $350
-Seas Xotic X2 W8 midwoofer -- $400

Hi everyone. I just re-implemented the UAC2 in another hardware platform. If you remember my last implementation is based on STM32, which is quite annoying to work with, involving a lot of hacking and tinkering. That project is quite incomplete also as DSD/DoP playback could not (or very difficult) be supported with peripherals on STM32, without core in the datapath, causing very high power consumption and instability. The new implementation is based on FX2LP, almost the stantard choice to communicate between programmable logic (FPGA/CPLD) and PC by USB. The core is completely out of the datapath, all logics are carried on the CPLD including buffering. Currently it can support up to PCM 768k/32bit 2ch playback and DoP detection (not playback yet). The project is still work in progress to be open-sourced, but I would like to share some progress with you.

I have have an original old SPU-GT Stereo with the original stylus intact & OK.
Also, a choice of arms, - RMG-309 - long straight arm or an SMG-212 - curved arm.

Are these worth using or are they likely to damage records?

R.

I'm building current sources and current mirrors that run at about 8mA of bias, and trying to decide which device types to select. Among the criteria I have considered, is the Early Voltage (SPICE parameter "VAF"), which determines the output conductance, the "flatness" of the Ice vs Vce curves.

I plopped a bunch of PNP thru-hole transistors on the curve tracer and found to my surprise, that they didn't match up to the Early voltage measurements in The Art Of Electronics 3rd Edition, Table 8.1a, page 501.

Here's a spreadsheet showing my measured values, in the vicinity of 8 milliamps Ice. And a few raw curve tracer pictures too. Hover your mouse over the image to read the part number; it's embedded in the file name.

I was slightly surprised and disappointed that the BC560 and BC327 were so crummy.

_

Hello,

I'm thinking about buying my first piece of vintage audio. I'm looking at a Pioneer SA-606 Amp and TX-606 Tuner Combo. I've never seen these models before and can't find much info online (I know, bad sign). Just wondering if anyone knows anything about them?

Thank you,

Matt

Hi,

This is my first post here. I've been working on fixing a low left channel problem on my Nakamichi CR-3 and swapped the L/R JFets and found that the fault migrated to the other channel. So Im assuming that it needs to be replaced. I've been looking everywhere for the 2SK371 but they are no longer available. Would anyone have a good idea of a modern or easier to find replacement?

I've got a ragged PPI PC21400.2 in for salvage if possible. The thermistors are broken on it. All but the one in the center of the transformer and one for thermal bias(this one I can pull and measure). If anyone has values for them it would be an excellent help.

TIA

Jason

I have two new, unused ICEpower 1000ASP Class D Audio Amplifiers and the cable kits. One was connected for testing but never used in production. Price: $150 each plus $30 shipping to 48 lower US states.

I recently built an open baffle speaker using a vintage Jensen 15" driver, three Jensen tweeters and a ribbon tweeter.

I'm wanting to build an open back subwoofer using the following wood. I'll cut it in half so that I have two 2' X 2' pieces.





I'll need a 15" 4 ohm driver that has a power handling of at least 25 watts. The crossover will be a passive 12 db/octave around 70Hz so that I can use one amp so the 15" driver needs to be rather efficient.

That said before I go and build a subwoofer I may not need, the main speaker baffle is 2' wide with a 15" Jensen woofer in the center closer to the bottom of the panel. Bass response is decent, but the lower end under maybe 50Hz is somewhat lacking. Would adding wings to the existing baffle make the bass response such that I do not need a sub? If so I've only got room for 1' wings on each side. I can either use a 2' X 2' cut in half or a 4' X 4' cut in half lengthwise whichever will work best.

Kind of a shot in the dark, but anyone have the older software/firmware for the TacT Audio S2150XDM they can send me? Not the S2150 (I have it), but the S2150XDM

The new software/firmware that is on the Yahoo Groups has the Room Correction capabilities removed (now why would they do that?)

Thanks!

Have gottten a specific wish from a friend.
How can one possibly and most simple make an input-select of 3 sources hum-free on the Pearl-3 ?
Suggestions appreciated.