Looks like an excellent small guide that should hold pattern control to mate with a 6" woofer. The narrow size is a nice option for vertically challenging speakers.

Dear all

I would really appreciate your help.

I just purchased a cheap 3020i.

I started by measuring and trying to adjust bias and DC offset. I de-soldered the short across R455 and R456 before adjusting bias to 30 mV.

All 4 trim-pots measure ok and are adjustable. Right channel OK (adjustable to 0 mV DC and plays).
Left channel no sound and DC >600 mV.

The preamp is fine and plays in both channels.

Could you help me fault find? Where do I start? I have a mulimeter and an ESR meter. And I can kinda follow the schematic with some help 🙂

Thank you - Morten / Denmark

Local pick up only
Seattle, WA
4 available
$200 each


https://www.parts-express.com/Dayto...Excursion-Subwoofer-22-ohm-295-292?quantity=1

I have been plagued by something I hear on occasion. It sounds like a fuzzy distortion, but only on select music.

Recently, I heard this and got up and closer to the speaker. It sounded like noise from the mouthpiece of the saxophone. Is that a thing?

Roger

I have a full box of these transistors in case anyone needs them.

$0.15 ea (min.100 pcs) or
$0.1 ea (min. 500 pcs).

Shipping would be flat @$10 worldwide (up to 500 pcs).

PM me if interested

Thanks for looking!

PSRR, power supply rejection ratio, is a pretty important parameter for a regulator.

This test was done with 21V input and 15V output in SPICE. The load was 100mA.
At the input was a signal 1kHz 300mVp-p.
The level of this signal was recorded at the output. The difference is expressed in dB.

The Super Regulator is outstanding according to my test.
LT1085 and LM7815 had somewhat poor PSRR at 1kHz.
LT1085 has a little better result at 100Hz

Result PSRR at 1kHz
142dB - Super Regulator, see image 1
125dB - My TL431 Regulator, see image 2
80dB - LM317
66dB - LM7815
62dB - LT1085

Due to health issues, I can't complete this project so it's here for sale.

I originally bought these from someone on here, the initial thread with details is https://www.diyaudio.com/community/threads/pair-of-fully-populated-ussa-5-25w-class-a-board.377760/. Pictures are on the thread, I've attached some pictures of the speaker protection boards which are from XRK, the version before this: https://www.etsy.com/uk/listing/932...41&click_sum=2d3298d9&ref=shop_home_active_12

2 x USSA 5 pre populated boards assembled by the designer Fab (see link above for details).
2 x New and unused Micro audio SMSPS500 - CLA, Aux voltage +-12 VDC, Output voltage +-25 VDC, with Mundorf upgrade
2 x XRK speaker protection modules

Looking for £500.

Based in Bristol, UK.

Collection preferred but can ship within the UK.

Good morning everyone,

I am an Italian enthusiast and this is the first time I have written, sorry for any English mistakes.

I've been having fun with diy speakers for fifty years.

I am now in possession of two pairs of Altec 420a biflex.

I have seen the features and different achievements on the web.

But I have a particular idea:

In your opinion, is it possible to make a speaker with a D'Appolito type configuration with a possible tweeter in the center?

I also have two AMT1a and JBL 075 tweeters.

Programmable electronic crossover , biamp.

I'd like it in open baffle, maybe paired with the subwoofer I have: SVS PB16 ultra.

Or in a closed box even of large cubic capacity, I have no problems with space.

Thank you for your opinions.

During the mid 70's I was involved with a small amateur theatre built in part of a Victorian house. As part of that install there were a couple of loudspeaker baffles installed on the wall, left and right sides of front-of-house, for interval music and some ambient sounds. The corner of the two walls became the speaker walls, with only the triangular tops and bottoms of the cabinets made to complete the sealed enclosure. The sound of that installation was excellent, with a nice warmth to the bass, helped by the wood, stone and velvet of the theatre auditorium. Although we ran them with just a 30w/channel amplifier there was more than enough sound for a good thunderstorm or party music.
That all said, I started again looking into corner speaker designs wondering why more use isn't made of using a solid brick wall for two of the speaker sides in a triangular shape. All design notes I have looked at suggest the 12dB boundary effect bass lift (or18dB if in the corner of three boundaries) is mostly undesirable, and I would agree, so why did ours sound so good... even without reducing low frequencies on the amp?
I've attached the only [very rough] picture I could find showing one speaker in situ from those days.



The speakers were actually the units from the KefKit 1 (B200 and T27+ crossover), and the baffle size was approximately 14in x 36in (35cm x 90cm), which would give an internal volume of around 1800 cu.in (~30Litres). From the Kef specs the recommended volume for the speakers was 21litres.

Would anybody with more knowledge of speaker acoustics be able to advise why they sounded so good yet this design is not made more of these days?

I have four complete Service Documentation binders on their Power, Pre, Tuner, Integrated and CD products.

See front of inserts to verify which products are included.

These are quite heavy, maybe 1-2kg. I guess the shipping will be noticeable.

€100/each + shipping at cost.

EU only please.

R

hi! im new here, really interested in designing amplifiers and bespoke multichannel audio systems for art projects. im completely self taught so please be nice

Greetings. I generated my first FRD file using ARTA. When I open the file in Notebook, I see three columns, though they do not have headers! They look like frequency, dB and phase. I imported said FRD file into Vituix CAD. The phase data is there, but the SPL data is not.

When I right-click of the upper left graph (where I believe SPL should be displayed) and choose "traces" the dialog box does not have a box next to "driver #1 magnitude".


I'm stumped. I can't find anything in the manual which covers this.

For sale are AC mains filter PCBs. Relative low parts count results in a very good filtering. I used many in the DIY projects I built for myself and several friends. Can be built for up to 6A Chokes by Schaffner but I usually used it in low amps circuits like my Soekris DAC or Shigaclone.

Currently around 10-12 PCBs at hand, asking 6€ per PCB + shipping + PP


Example build:

Hello,
Thankful for all your posts in the forum, I've been reading it for some time and have learned a ton.
Hopefully I'll be able to contribute something to the community as well one day.
We have a 400 seat indoor venue ata Youth Camp that hosts our live band. We're running (2) QSC KW153's (15" 3-way speakers) for mains (flown above each half of the audience). We were running (2) cheap Harbinger 18 boxes that are being moved to another venue to replace (2) 12" subs that got blown..
So, now we need to build new subs for the main venue.. we can place them UNDER the stage if the cabinet is < 16" tall otherwise we have to find alternative locations or fly them.
The music played is contemporary Christian songs with some TOP 40 style beats (music only)

We have (1) QSC PLX1602 amp to power the sub(s). It's capable of 300w @ 8ohms, 500w @ 4ohms and 800w @ 2ohms or 1600w bridged at 4ohms.

We can run one or two subs, we just want something that will keep up with the mains and provide that 'chest thumping' bass and low end to cover the entire instrument range (bass, keys, drums).

I have extensive Home Audio and Car Audio experience so I understand box modeling, T/S params, speaker/enclosure/room interactions but am a total noob when it comes to Pro Audio.. which is why I've got my hat in my hands asking for advice from you, that have more experience!

The two designs we have been looking at: (though we're open to other suggestions):
Cubo 18 Extended with a PD.1850 or B&C 18NW100
- OR-
The Keystone TH running B&C 18SW115 - possibly just ONE, with the amp bridged to it ?? I know this seems counterintuitive, but with the excursion capability of this driver and double the power, one 18SW115 should be close to (2) PD.1850s or 18NW100's... or very close to it. Then we can build another when we have more in the budget.. and another amp.

Love to hear your thoughts on these, or recommendations for other enclosures we can DIY for this system.
@weltersys

I have experience with 32W/4878T00 in closed box and this woofer definitely did not sound good and clean in lower midrange with ~300Hz LR2.

For new project I would like to have better sensitivity and old school look cabinets with 12"+4-5"+1" drivers.

T11 main differences compared to T00/T01 are foam surround single layer paper cone (T00/T01 have 2layers with foam filling). Of course TS parameters differ as well. All this promises cleaner lower midrange performance.

I am also considering SB34NRXL and 12RS430.

Thanks for any thoughts

I have a set of BK 20s folded BLH from madisound I built some time ago gathering dust. The bass response is not horrible but not good.

I have been toying with the idea of closing off the horn mouth with a piece of plywood and leaving a slot port to make a mass loaded transmission line of sorts out of them.

Is this feasible or just crazy? I know absolutely nothing about speaker design nor do I have the knowledge or means to model or test such.

If it all feasible, any suggestion to port size and placement appreciated. Even just a rough starting point

Seems like an easy experiment and a bit of fun—curious what others think.

Hi all,
I am fixing an audio research D-100B power amp. I think the output power transistors are dead. I don't know the part number printed on the transistor cover. What printed on the cover are motorola 300027 7926 and motorola 300026 7852. Apparently, they are complementary pair. I think the number is only for audio research interior reference.🙁
Anybody knows what they are??
Thanks alot!
Lhchen

Hi,

I have a pair of Fountek NeoX 3.0 Ribbon Tweeters I salvaged.

Would an "on desk" enclosure with three PEERLESS TYMPHANY 4" mid-woofers and the ribbon be a good idea, crossover with one of the woofers doing mids and bass and the other two just bass?

Not sure on sealed or ported.

If it's a good idea, anyone seen anything like this 4" cheaper in Australia, the Peerless is $60 and I'd like something around $40 that can get up to the ribbon KHz.

Thanks.
RIchard

For sale HPA1 Clone. Unfinished project, PCB is tested.Everything functional. Made as dual mono. Price 150€.

Hi !
Does anyone know anything about this jfet. (complementary ?)
P-Ch JFET
Blue-G, Symmetrical Src/Drn
Vgs(off)=-4,38V at Id=4,8µA (~ 4-6)
Vgs(on)=0,16V at Id=5,00mA
gfs=1,5mA/V at Id=3,0mA to 5,0mA
Idss=4,79mA at Vds=3,00V
Rds(on)=535,0Ω at Id=5,0mA and Vgs=0,0V

I found in my stock a pair of the original Hitachi Mosfets 2SJ50 and 2SK135 from the '80s and during the lock-down I decided to rebuild the Linsley Hood 80-100 Watt Mosfet amplifier published in the Wireless World magazine in 1982 that I had also built in the '80s.

I designed a new PCB since my original PCBs, as published in the article, were not in good condition.
I also reduced the supply voltage to +/- 35 Vdc because I didn't need more power than 40 Watts / 8 Ω and I used modern components.
To my opinion this amplifier is still very, very good and I was very pleased with the final results.

It was so good that I ordered a pair of Exicon Mosfets, that according to their manufacturer are direct replacement for the Hitachi Mosfets, to built one more amplifier.
In comparison with the Hitachi Mosfets, I think that Exicon mosfets have a little better transparency.

If you are looking for an amplifier to build, I fully recommend it.

Here are some photos of the assembled PCBs.

Hi everyone,

I’m Magnus, a photographer and filmmaker based in Stockholm. I'm looking into getting a good sound system, and the challenge and reward of a DIY project really appeal to me. I’ve looked at so many designs, and I’m currently leaning towards the Mechano23. It seems to be fairly straight forward build, good value for money and a great sounding speaker.

BUT, the problem is... that once you start researching, you end up wanting the best of the best. That’s how I got intrigued by Scott Hinson’s Multiple Entry Horn. Unfortunately, the components are a bit out of my budget right now, but maybe I'd be able to do a mono speaker at some point.

For now, I’ll likely stick with a simpler build, like the Mechano23. If you have any other speaker designs you’d recommend, I’d love to hear your suggestions!

Cheers,
Magnus

I have for sale 2 boards, of this excellent PSU, suitable for preamplifier, headphone amplifier.

Heatsinks height: 25 mm
Output voltage: Set to 15V

Price: 30 eur/board
Shipping: Worldwide
Payment: PayPal

Greetings from Athens

Hey all!

Been a lurker for a bit and figured it was time to create an account. I am a software peep and have spent some time dabbling with dsp/SHARC, speaker correction, and codec work. Learning hardware aspect of things in my spare time. I'll probably ask a few questions haha.

Cheers,
Barold

... until I tried to replace an audio source (from a HDMI Audio Extractor device, unbranded), with the analog audio output of a SKY HD receiver (available in the SCART socket).

The result was very disappointing, the audio level was about half of that delivered by the extractor.

I can compensate by increasing the volume on the amplifier driving the ceiling speakers (sports bar venue), but that don't seem to be the right thing to do, as the punters like it load during important footy matches.

If I've got to use pre-amplifiers, I'm not going to achieve anything by trying to remove what I thought was superfluous kit....

The audio out from the SKY box was not variable with the "Volume Controls" on the SKY remote. is there a way to boost it ?

TIA

Hi,

Here is a small, low-voltage (3V or less) amplifier.

I wanted a signal-tracer amplifier, very small, and battery operated to be used in completely floating situations: like typically to measure the noise across a component.

This amplifier fits the bill. It is rather crude, but has some interesting features: it uses same-sex output transistors, operates efficiently at ridiculously low voltage levels, and yet offers a decent quality: here, it is shown at max output power, and the THD is well under 2%, with a nice harmonic profile.
At lower power, the distortion is even lower.
Also note that the gain is very high, because of the intended application.
More reasonable values would further decrease the THD, and increase the input impedance.
The peak to peak output voltage before clipping reaches 2.5V with a 3V supply, which is quite impressive

No temperature compensation is shown; for optimum stability, R4 should be an NTC (or an NTC should be part of R4).
But even without compensation, the stability is acceptable thanks to the low supply voltage: the total quiescent current establishes itself at ~10mA.

The polarity of all transistors could be reversed, allowing the use of germanium transistors: the only adaptation required is R4, that should be changed to 39 or 47 ohm.

R9 is optional, it slightly improves the THD and the stability.

Have fun!

$75 plus shipping. They have not been used. They have some pretty glowing reviews online

I sale amplifier AUDIOLAB 6000A in silver finish. The amplifier is fully functional and is in new condition i.e. without any signs of use. Complete accessories and original packaging available. The amp is free of any scratches, dents.

I am the first owner, the amp is 2 years old.

https://www.whathifi.com/reviews/audiolab-6000a

I only send within the EU. (paypal, wire transfer)

Price 500€ (incl. shipping)

For the end of DIY activities I am selling this SET.

2x PEAR3 PCB
8x 2sk170 (are originals from one member here from the forum...)
1x UDP3 board
1x inteligent softstart + ATina

Sold only as a whole at a great price (70€ + shipping)

Payment via PayPal or Wire transfer

Hi
I would like to buy a set of Mirage speaker on Blocket.se
I cannot register from Denmark.. Can any Swedish members help me out..

Best regards
Kim L. Poulsen

I have a datasheet with the following parameter:
Common-mode input voltage range

What is this?

Values:
Min 0V
Max VDD-1.5V

Hello, new here. I'm interested in building myself some compact subs for a pair of B&O BEOVOX S30 speakers that I have.

Look forward to discussing some design ideas.

I thought I would share my solution for easily prototyping passive crossover filters.

I designed and made a few modular boards that can easily be connected to each other. They make it easy to try out different topologies and to compare different component values. Here is an example of a basic 2nd order 3khz crossover with a 6db lpad on the tweeter.



Since my speakers (live edge open baffles) emphasize the beauty of natural wood, I decided to make these from solid walnut with a natural hemp oil finish. Completely unnecessary, I know, but hey, it makes me happy ;-) These boards weren’t the cheapeast or easiest to make, but I had fun making them.

Busbar



The busbar units feature two (2) push terminals and six (6) mini banana plug terminals, all wired to each other.

Typically I use one busbar module connected to the amp’s positive (+) terminal and one connected to the amp’s negative (-) terminal. If building a parallel crossover, I can branch out to each driver’s individual circuit.

Busbar JR


The busbar JR features one (1) push terminal and four (4) mini banana plug terminals, all wired to eachother.

These are useful in series crossovers and the occasional busy junction.

SP



The “SP” unit stands for “series parallel”. This module puts one component in series with the output and one component in parallel with the output. It can be used for many things, such as creating an LPAD, an RL high-pass filter or a 2nd order filter.

The inputs and outputs include two (2) positive input terminals (+), one positive output terminal (OUT +) and two (2) negative terminals. By doubling up the positive and negative terminals, these modules can easily be daisy-chained.

The series component is connected with two push terminals. This makes it very easy to swap components to try different component values. The series connection can be shorted with a short length of speaker wire to use the SP module as a single parallel component.

The parallel component is also connected with two push terminals. The parallel component can be omitted to use the SP module as single series component.

There is additionally a “bypass” DPDT switch that shorts the series component and opens the parallel path. With the bypass engaged, it is as if the components have been removed from the circuit.

SPSP

The “SPSP” unit stands for “series parallel series parallel”. This module acts like two SP units sequenced together, “A” and “B”. It can be used for many things, such as:

• A fourth-order high-pass or low-pass filter.
• A second-order high-pass AND a second-order low-pass filter.
• A second-order filter AND an LPAD.
• My personal favorite: an RL high-pass filter AND an LPAD.

The inputs and outputs include three (3) positive input terminals (+), two positive output terminal (OUT +) and two (2) negative terminals.

There are two DPDT switches. The first bypasses the first SP components (“A”), and the second bypasses the second SP components (“B”).

The switches open up lots of possibilities, such as:

• Compare different LPADs on “A” and “B”.
• Compare different second-order filters on “A” and “B”

Connections

I use small lengths of speakers wire with solder-on banana plugs to easily wire these modules together and to the speaker drivers.

Thanks for letting me share!

I’ve been searching everywhere for a tube CD player That will match my Elekit 8900 356mm width. The closest match I found is the Cayin A-50CD which is 350mm (13.77inches) wide. Only issue is the voltage is 220v , with no option for 110v.
What cd players are you all using ? I wish Elekit made a cd player again….

In an effort of simplifying my life I’m considering quitting the DIY route. It takes me a long time to get stuff built (two years in on EL34 Baby Huey’s and don’t even have all the parts yet) and I’m thinking it might just be easier to buy good quality gear and be done with it. I’ve built tube amps, guitar amps, speakers, etc. what’s happening also is I’m ending up with stuff I have no room for too. I enjoy the process, but I’m in my mid 50’s and would rather spend the time listening instead of building, tweaking, etc.

Anyone else been in this predicament?

Hi everyone,

I have been having issues with an Infinity Intermezzo 3.5c Centre Speaker. The mid is very very low, almost no sound.
I have traced it back to one of the capacitors.

The service manual shows C6 as 2.5uF 100V, however on the board itself it says 25uF 100V.
Since it's by a factor of 10, I'm hoping someone can look at the XO and can confirm if it should be 2.5uF or 25uF.

The original cap is blown and the jacket on the outside is damaged so I can't read what the actual value is on the old cap.

Any help would be appreciated.

TIA

I couldn't find an answer anywhere. There is a new driver brand I'm working on a design for and I want to use a passive driver. They don't have one. Can you use passive drivers from a different brand? I did see this every now and then, but how to match them, where to look for? And as a second solution, can you use a active driver as a passive driver?

Wanting to find DIY Speaker builders in the Springfield MO area. I am currently working on an open baffle speaker. I made a passive crossover but want to adventure into the world of actIIve crossover using a MiniDSP Flex 8. If there is anyone with experience with the MiniDSP and setting up an active crossover? I would appreciate talking, learning and sharing with them. Thanks for considering answering my request. Greg (Ozark, MO).

Have 50C5 SE output transformer would it work with 6AQ5 tube don’t have LCR meter any recommendations on one from Amazon

Hi,
I am a new OB from Italy.
Thank you very much for maintaining this very good forum.

I have for sale LM1875 chipamp boards + psu boards 8chanels + 2 additional psu boards + LM1875 chips 8pcs.

35EUR

Payment by paypall+papall fee+ shipping.

I have the 2023 pre-release version of the Iron Pre essentials kit, plus the completion kit that was offered earlier this year. Both are untouched, and will sell for $200 combined, which is below the asking price when the full kit combo kit is in stock. Will also cover shipping in the continental US. How's that for a deal??

J

Finally accepting that I’m just not going to get a chance to build cabs of the proper size for these so hoping someone else here would like to instead.

Drivers bought from another audio forum last year (or maybe the year before?). I collected in person so they wouldn’t be subject to any rough handling. I believe they had been stored for the best part of a decade before I bought them.

The ARUs were bought more recently from eBay and are in very good condition.

Drivers are in good condition with no cone rub.

I used them for about a month in my Tannoy Chatsworth cabinets which unfortunately are not big enough to get low bass out of the Goodmans. The quality of the drivers was quite apparent however - they are cleaner and more transparent than my Monitor Golds - and I’m certain that in the right cabinet (120L+) they would be very satisfying indeed.

The single crossover cap has been replaced (with a Mundorf IIRC) as the originals were far out of spec. I also bypassed the L-pads as per advice on here. I have the aluminium containers for the crossovers.

These are for collection only from Edinburgh, Scotland as I just don’t have time to organise all the packaging that would be needed to ship them safely. And even then I would be reluctant - I don’t suppose there’s many examples of these around nowadays.

I’m thinking £400 for drivers and ARUs but may be open to sensible offers.

Pictures to follow as soon as there’s some decent light.

Cheers

Ian

I bought 5 of these from JLPCB I only need 1 so if anyone is interrested Im selling the 4 leftovers.
Asking 10euro + shipping.

https://www.diyaudio.com/community/threads/gainwire-line-phone-non-gnfb-preamp.395695/#post-7265671

Hi all,
I'm new to speaker building (although I've built multiple amps and preamps) and picked up two Faital Pro 12FH500 4 ohm woofers for a very low price. I'd like to build a two way speaker out of these and need a recommendation on the tweeter and ideal crossover point. Should I try one of the Faital compression horn drivers? Does it matter they are 8 ohm?

Thanks!

Brad

Hi everyone, I am raising some fund for a new turntable purchase. So, I will be parting with a pair of power transformers and 4 chokes from Muse Coils. These are the state-of-the-art Minotaur series. Please email for pricing for these bespoke products. Here are some photos.

banpuku@mac.com

I've been an analog audio enthusiast all my adult life. I'm a retired engineer and programmer, and have a second hobby of B&W film photography. I'm here because I have an RCA/Radio Shack receiver that has croaked, and I'd like to troubleshoot it myself, rather than take it to the recycle graveyard.

I have been in the process of researching and preparing to build an automatic measurement table for a while as making a large number of measurements manually is no fun and very time consuming.

I came across a great website I thought had everything I needed laid out and documented.
http://nicholasmart.in/measurement_platform/

I started getting together all the things I would need and came across a stumbling block. The software exe to have ARTA communicate with the Tic controller is not on the website and the author did not respond to my message or another request posted on another forum that seems to be discussing the same thing.

https://www.audiosciencereview.com/...ar-measurements-using-arta.14282/#post-438440

I started looking at coding it myself and quickly realised it would take me a long and frustrating time if I tried. Fortunately @Tom Kamphuys agreed to help me out with his coding skills, the reason this software works and is available here is due to almost solely to Tom's work.

He has created a github page where the source code is available. At this time the exe is not there but is attached to this post in a zip archive with a basic readme file to explain it.
https://github.com/TomKamphuys/Arta_Tic

This software was created to control a Tic stepper motor controller from Pololu via the ticcmd command line utility. ARTA sends commands to the turntable driver exe which interprets and passes the correct commands to ticcmd.

I have chosen to use the Tic 36v4 as it has the maximum current capacity (4.0A without extra cooling) and a NEMA 23 stepper with a 2.8A maximum current rating. These are probably overkill in most circumstances but I wanted to have the option to move heavier loads. In theory if the friction can be kept low enough these components can move more than 100Kg in the configuration I am building.

My setup will use two 600mm pre cut red oak circular table tops with ball castors in between. The red oak was chosen as it was stiff, solid and on special for on $10 AUD each.
The gearing will be a 360 tooth GT2 main pulley mounted to the table top underside with a 20 tooth pulley on the stepper with a closed loop GT2 belt. Very similar to that in the above measurement platform article. Underneath there will be a pine base frame to aid in stability with levelling feet.



The pulley I have designed contains a 1" bearing that fits a 1" OD Aluminium tube piece used as a centre pin. I wanted to make this solid and low friction so the large bearing and tube seemed to fit the bill. I will make the pulley STL available once I have printed and tested it to make sure it works.



I have made a prototype without gears that functions as intended. I was able to make a 0 to 180 (10 degree increments) set of test measurements with ARTA on my laptop that took only a few minutes to complete.

@jcga was keen to update his existing ARTA turntable with a different motor and driver. He has also been able to use the software to move his table successfully, so I thought it worth making a thread to post the code in case this is useful to others.

Here is some information that might be helpful for set up to explain more of how the code functions
https://www.diyaudio.com/community/...-motor-and-tic-controller.387325/post-7769495

I went through a couple of different mechanisms before going back to belt drive. The final outcome can be seen here https://www.diyaudio.com/community/...-motor-and-tic-controller.387325/post-7776912

Good morning everyone, I'm trying my hand at building an 18" subwoofer with a Faital Pro component, the XL 1800, that works in a sealed box.
To move this subwoofer I will use a Powersoft module with a Loto DSP that has the crossover function inside.
The software called Harmony is very cumbersome and quite difficult to understand (at least for me who doesn't know this software). There are 3 equalizations with filters and slopes, so I think it's enough to choose one to create the filter.
Intuitively I modeled the subwoofer with a slope of 24db starting at 20hz with a high pass, the remaining frequencies are peaking up to 150hz, after which I have the low pass filter at 150hz with a slope of 24db. What I'm asking, are these the right filters to use to make it work correctly? I'll attach an illustrative photo later.
Thanks.
For those who want to take a look at the functions of the DSP I leave the link, the part interested in the development of frequencies and eq. is from section 8-3 onwards
https://www.powersoft.com/wp-content/uploads/user_guide/PS_LOTO_UG.pdf

Greetings! In a recent post, "What is this technique called?", mortron asked about ring slot-loaded woofers.

Not sure if this has already been discussed, but apparently KEF has some experience with ring slot-loaded woofers in their triaxial Architectural speaker, the Ci250RRM-THX. The White Paper is certainly an interesting read. Wondering if this design could present a viable foundation for custom HIFI loudspeaker design, i.e. using larger format drivers? Any thoughts?

Product Page
https://us.kef.com/products/ci250rrm-thx

White Paper
https://images.salsify.com/image/upload/s--NpCBx-SO--/w9cbdm861tt4vimzda3g.pdf

Specification Sheet
https://images.salsify.com/image/upload/s--eAiklJpu--/tvle4ezw8itx5p19ba7v.pdf

Discussion
https://www.audiosciencereview.com/forum/index.php?threads/kef-ci250rrm.37929/
https://www.audiosciencereview.com/forum/index.php?threads/kef-ci250rrm-thx.39104/

Selling this entry level Andrea Mori clock. It has a squarer on board so can be fed a sine.
Runs on 6.6v.
Was an honest upgrade over the NDKs I had in the FifoPi. I used a Ti TPSA7 regulator as PSU.
Good upgrade without spending lots and having a complicated set up.
£40

Me again! Need to bypass the above from Akai sw155 speakers. I've tried to clean the pots with electrical cleaner (deoxit) but still nothing! Let me rewind, Akai sw155 4way speakers just popped up and naw I got them. At the rear of the speakers we have controls for high and mid. Plugged them in and it was all wrong, scratching pots as I turned them. Decided to clean the pots but no. One speaker is intermittent, other has no high frequency (tweeter/super tweeter)
Adjustments can be made at amplifier so I'd rather bypass.
Sorry unable to take detailed pictures but will try my best.

Selling this battery PSU.
The small SMD switch has lost its little tab. It is in the 'ON' position.
The batteries in it are actually 3.2v and not 3.3 and the output from the PSU is 3.15v. I used it on the clean side of my Fifopi with no issues.
Take care with the input voltage as it does get hot if fed too much AC. Once it's all charged up it settles down thermally. I just tested it with a 2A 5V USB C and it soon gave me the blue 'Pure' indicator.

£50 plus post.

I need to replace PSU caps in my 2 KD990 t/ts. They are Elna 2200uF/25V snap in 25mm w x 18mm d. There is a Polish guy on Ebay offering a complete set of electros for the KD990. I don't need a complete set just the PSU caps. I left a message on Ebay hoping he would response - no joy. I can see he's using 2700uF/50V which are the same size but I can't see the make. Can anyone help?

Unfortunately just the one of these. I used it in a centre speaker. Slight crease in the cone .
With gasket
£10

New unused. One unopened.
£20 plus post

I was thinking about removing the ST and the 4way becomes 3way how?
Can I put in parallel this 4uf from mid to tweeter, will the T be able to cover the very high frequency thus removes the ST?
I got pic of crossover

as above. Spoken voice, not music. Thanking you kindly.

@weltersys made a comment recently which has confused me. I recently acquired an Audica SUB10 with a faulty plate amp. I discarded the plate amp and made the unit passive. However, the plate amp was housed in its own 6 litre compartment. I used a hole saw to make a 60mm hole through to the main chamber, adding the 6 litres to the main cabinet volume. @weltersys informed me that I'd created a Helmholtz absorber @200hz.
What does this mean?
What are the benefits of making another hole?

Looking to build a PA system for my church , i have some knowledge in mixing sound etc but putting the Speakers together trips me up...
My top Cab Amplifier is pushing 1050w RMS @ 4ohms so I would like to build something around that power rating.

Can someone please point me in the right direction in building this...

I have empty cabs so i need recommended Compression drivers (tweeter) 1-3/8 TPI thread and recommended 15"s DUAL SETUP then Ill also like to put in a 3 way Frequency driver/crossover

Technically I just need the RMS wattage of these speakers that will be able to SAFELY go along with the amplifier @ 4ohms any help would be greatly appreciated.
Recommended speakers would be a plus 🙂 save me time looking around altho i do have a budget but ill at least know what im shopping for.

Just came across this relatively new part and haven't found any discussion, finally a low cost solution for USB isolation with high speed devices, basically all modern DACs at this point.

Should allow an external isolator to be easily added to any USB DAC, might not hurt to have this extra layer of isolation in DACs with internal post-USB isolation either.

Hi everyone,

I'm new here, so apologies if I'm framing this in the wrong way or posting in the wrong forum.

Hopefully about to get married next year and we found this fantastic venue. They have a large outdoor greenhouse of 7x14 meters (22'11" x 45'11") just by the water, that seats 100+ people.

Now, we talked to some other friends who just attended a wedding there, they said everything was great except very loud noise level in the greenhouse, could barely hear your neighbour across the table. From what I hear, glass is the worst offender when it comes to sound reflection, which is kind of worrying.

Need some help/ideas what measures can be taken here to reduce the noise level, while keeping it wedding appropriate? My own ideas so far involve hanging white heavy fabrics across the ceiling, and some type of curtains in the corners perhaps. Not sure how much it would help. Appreciate any pointers.

Attached a partial photo of the greenhouse I found in the venue gallery (backside is facing rocks, could possibly be covered by curtains).

Hallo Im from Italy
Im new in OB...

Hi All,
Tungsol or WE. As long as NOS
Tks

Hi, I have recently bought a Luxkit A 2002 active tube crossover. There was someone supplying a manual in pdf form, however his website is down and his e-mail address and phone number don't work anymore. Does anyone still have the manual for the A2003 or A2002 lying around?

Hi all,

I'm a software engineer turned entrepreneur and sometimes manager. I have too many hobbies and not enough time, but I figure that's going to be pretty common around here 🙂

Since I had a few months between jobs, and a pair Tang Band W8-1808 turned up on the second hand market I decided that it was time to stop reading about DIY speakers and actually do it myself.

You can also find me here: https://larsan.net/

I'm happy to be here!

/Fungrim

1. Fully assembled K&K Audio High Voltage Power Supply with Jensen 50uF 250VDC MP/oil cap. It has a time delay kit for the B+ Voltage.

2. Fully assembled K&K Audio Shunt Regulator Kit (max 350VDC, 100mA) -- 2 piece

I have user manual which I will share with buyer via email.

Bought for a project but never able to finish it up. So available for sale. Asking $200 USD, will ship anywhere at buyer's expense.

Let me know if you have any questions.

Just got a new pair of Mark Audio Alpair 11ms. Beautiful drivers. Thinking about a Nostromo build.

Friends, who can tell me what caused such a wild shunting of the amplifier for the German market? Are these such requirements? Or is it a "correction" for German hearing? Look at the diagram, IMHO, the removal of a heap of containers (indicated by the letter G in the diagram) should have a positive effect on the sound. Any opinions?

Hello everyone
I'm repairing a clone BASSFACE 3000W class D mono block with dead power supply and output section.
When I fitted the new FETs and drivers, I noticed big inductive spikes on the drains of the power supply mosfets.
I already brought down the frequency to 20 KHz to minimize the effect on the mosfets.
Is there any way to get rid of these spikes or it's just a bad design of the transformers and nothing could be down for it?

Hi Guys,
I have my Classe Ca-200 amp blew up on me a few days ago. I opened it up and found two of the 18 heat-sink mounted transistors have burned. I have tested the remaining 16 and they are ok. There were two small transistors that I can figure out the part number for them. The one for the left channel is labeled as Q108 and Q208 for the right channel on the board Here is a copy of the section of the schematics for the left channel of the amp. Can someone please help me identify the part number for Q108?

I am looking to buy a house that has a decent option for an audio room. It is about 12' (3.6m) wide and 28' (8.6m) long. I would prefer a bit wider and a bit shorter, but it's better than most options we've seen so far. It's on the ground floor. The floor is tile on concrete. One long wall is probably concrete blocks with plaster and two french doors. The other three walls are (I think) plaster blocks. The plaster is all bare - no wallpaper, paint, or anything on there. It's quite live right now. I'm wondering what I should be looking at for wall treatments to make it more neutral. There will be a couch in there, and probably an area rug, which will help a bit. Acoustic wall panels look to run about 175 euros per 60cm (two feet) of wall length, which adds up pretty quickly even if I'm looking to do live end / dead end.

The speakers in question are Magnepan Tympani IVs, with the mid/tweeter panels separated so they can be placed in front of the bass panels. The sub is a VMPS new larger sub. The room is smaller, or, at least, narrower, than the room I used to have this setup in. Oh, I also do have a DEX2496 and DEQ2496 which can allow for quite a lot of EQ to help adjust for resonances, at least.

Ideas? Wood panelling, maybe? Thanks!

Hi
As i have been burned quite a few times thinking i know the right connector and failing (having to re-order...), i would be grateful if some could help me identifying the connector on the picture.
It is mentionned a 2mm pitch on the PCB. It connects a keyboard pcb to a usb-A cable.
Given the 2mm pitch on pcb, is it for sure a PH or a PA (refering to link ) ?
Thanks in advance
ps:
Purpose: ordering the counter connector with a cable to change the type of mechanical connection (usb-c instead of usb-a)

Does anyone know what the recommended line input voltage is for the tda7498e? I've read the datasheet a couple times but most of what I'm reading is above my head and it isn't clearly stated.

hi,
question: I got two ACA 1.6 amps. One with power switch in front and a stereo/mono switch in back (amp1). The other has the power switch in back and no stereo/mono switch (amp2), it's just wired for stereo.
I want to use the two amps as monoblocks, each amp powering one speaker. When connecting the cables like in the build guide, I noticed less power coming out of the amp with no stereo/mono switch. Am I correct that this has to do with amp2 only using one channel for amplification, not both? And, would a solution be to use XLR outs as those seem to be wired to both channels on amp1 and amp2? Or would there be another solution that's practical.
Thanks in advance for any advice!
Martin

Hello, looking forward to getting to know you guys. I am into tube amplifiers and have started designing my own recently. After getting a better understanding of how stuff works instead of just following a schematic.

Regards, Tom

A ECC88 and 12AT7/ECC81 from rebranders Hoges and Haltron respectively.

The Hoges ECC88 has a strong resemblance to Siemens tubes of the same type, like the getter installation and two-step support. But I can't recall seeing that first step metal plate being circular with no machining/cutting done to the part.






The Haltron ECC81 looks like the Philips family of tube construction. It very much resembles a Mullard (Philips branded) ECC81 I've got, but as the Haltron has four glass seams at the top this is apparently not possible. Another guess would be the Indian BEL factory who collaborated with Philips/Mullard. As a matter of fact, it reminded me of a BEL E81CC (Zaerix branded) that I brought to attention in another thread (https://www.diyaudio.com/community/threads/zaerix-e81cc.404144/). The look very much alike, except that the Haltron has ribbed plates versus smooth ones on the BEL/Zaerix.






Please chime in if you have any thoughts, suggestions!

V8.0.0 is released
Read the blog posting for a summary of the new features
https://www.kicad.org/blog/2024/02/Version-8.0.0-Released/

Hello Guys,

I'm looking for a good DAC kit (or assembled).
I'm listening music in CD quality, but some frequency correction is also needed, so a 20bit or 24bit DAC would be fine.

What I already found:

• Ladder DACs on ebay (for 65EUR or much more)
• Some PCM61, AD1865 based products, also on ebay (about 100 EUR)

I afraid, none of them are good quality designs.

I have seen some Abraxalito DACs here (I'm sure they are all well designed DACs), but all of them were 16bit only.
Do you have any recommendations for other valuable NOS DAC kits?