Has anyone found a decent Quad 405-2 clone board to recommend.
Thanks.
thyristor44

Can anyone recommend a kit 405 board.

There is something that I wish to understand.
The svs pb16 has 3 3.5" round ports which comes out to a cross area of 186.2cm^2
I don't know the sd of its 16" driver.
For a 15" driver like sw115-4 has an sd of 855 so the port area vs sd is 21%.
Would the svs pb16 chuffed at low frequency high spl? Would it need around 1/3? May be the 16" has a ridiculous sd?

I now have my 10p enABL2 based Halcyon speakers working well and sounding pretty good. I do sense a bit of congestion when played loud in the upper end, which is dominated by the 10P. Mind you, they sound very good, and are pleasant to listen to. However, I wondering if the MAOP-10 or the metal 10m would solve my issues? I listen mostly to classical, Jazz, vocals, etc. No rock.

The extra cost of the MAOP-10 is not an issue as I have spent way more in the cabinets and crossovers (and the amp and dacs to drive them) then the costs of the original 10p driver by several times. I will have these speakers for a long time and am curious to know if I can squeeze the last bit of performance by the MAOP-10s. With the Halcyon Design, bass is not the issue as the bass duty it handled by a pair of SB acoustic woofers on summed transmission lines.

It is the mids and high end I hope to improve. I would appreciate any insight from anyone on the forum.

-david BTW

Hi Guys

Could someone please help with IC number for IC1 and 2.

Thank you in advance

I just finished building a TI chip class D Jerry's Electronics kit amplifier....In a couple words..Extremely impressed at what a $35 amplifier can sound like. I posted a YouTube about the experience....Hope you like it.... Login to view embedded media

1st thread so hello to all. Apologies in advance, i don't often post in forums so will try my best!

So as title, I want a pair of PA style speakers that will be mounted in two corners close to ceiling. They will be used for Karaoke, DJ sessions and small parties in a 62m3 room. I am hoping to make use of a spare NX3000 amp I have to power them and I also have a twin 10" DIY sub low passed @ 100hz, also powered by an NX3000. The sub is hooked up to my 5.1 Diamond 220 setup, Pioneer LX73 Receiver and does more than I need, for now!

Buy or DIY? Simpler to buy but from my experience always better and more satisfying to build.
Things to consider. Although no expert, i have basic wood working skills and tools such as, table saw, plunge saw, router etc and have already had a go at building 2 different sub boxes, so I feel comfortable enough to build myself and want to learn more anyway.

I've been looking over the "so you want to design your own speakers from scratch" thread and have taken notes on "determining basic needs". I will be honest a lot of it went over my head or may not apply to my situation. I am hoping that by answering them question here along with some notes, I could get some advice and recommendations.

Basic needs....
Space is not really an issue, the two corners are free to make use of, within reason of course.
How Loud? Based on the following i would say pretty loud lol. 1 : We already know what amp will be used, it is rated at 2 x 900w @ 4ohm or 2 x 1500w @ 2ohms so I will have plenty of power. 2 : They will be used in a party/dj environment and i already have a really good sub to back them up.

We listen to lots of fast paced dance music so need something that responds well. We will be using for karaoke (SM58) lol and listen to plenty of vocal music so we want something that's going to make vocals sound nice and bright. In this case i would say we were after something the opposite of flat speakers.

Boxes, as mentioned I will be building so no cost to consider other then materials, that I still have here and there 😉 They will be mounted and I need to work out how I am going to do that. One question here is do I need/want ports? From my understanding, loosely, a ported box take less power going down low vs sealed that requires more power but result is clearer bass tones. Although, seeing as I have a ported sub that's filling the room nicely and an amp with plenty of power ready, it makes me wonder if i am better off going with a sealed enclosure on this occasion as its more the clarity and detail i want from them anyway. Thoughts on this appreciated.

Tools, The one thing i may need here is "measuring equipment". I've got all the woodworking covered, I have a windows PC but what equipment do I need to start me off? I presume at the minimum a special microphone.

Crossover, At present I need to look into this a bit more. Designing on computer will be one thing but testing will be another. I am leaning towards passive crossover however.

Budget, 250 - 350 but maybe able to stretch a bit. This would be for speakers and crossover parts only. No labour cost and I'm not including the wood cost either, I have lots left over and its cheap for me around here.

Speaker type, 2 way and I'm thinking 12 to 15" driver unless 2 x smaller would be better for more detail in the midrange? I always see horns in PA speakers and this made my mind jump to them automatically. However I would appreciate any recommendations for my application, in the meantime I will be researching tweeter types as I have never, until now need to buy any.

Sorry if a long read guys 🙁 again I don't often post and have problems sometimes explaining myself.

I've looked over some really good guides and found some awesome material but unfortunately most of what I'm finding is related to 2 way or 3 way full range designs and mentions about adding a sub afterwards.
My situation is i have the sub covered first and i feel maybe wasting money and time buying speakers designed for sub 80hz and tuning the boxes as low as they go etc. When in fact the money and time maybe better spent!
I feel I don't know enough yet to make a better choice and the more I google around for drivers and start comparing spec/prices it all get a bit overwhelming tbh!

I am terrible with words and only hope that this makes sense. This is an ongoing project so I will be indeed researching as I go but appreciate any kind words you guys have to share 🙂

Apparently JLCPCB has a 3D printing service now. Prices seem pretty low, and they're able to print some pretty big parts.

Only challenge is that when I try to upload the .STL file for the augerpro waveguide, the units are wrong with no obvious way to change it.

Anyone used this service or have an idea how to work around this? Their PCB fabrication is usually pretty painless and reliable, so I'm interested to see how their 3D printing capabilities are.

If it's cheap enough, this could be a huge deal.

Nice Distortion Meter from LEADER Model: 1701.
With two inputs, RMS meter , Fixed 1Khz possibility of 100Hz/10Khz (NOT installed). Monitor out for FFT on computer. GO/NO-GO test. Everything works perfect. Price around 400EUR or come with an offer!

I have a Sansui AU-717 integrated that I bought new with paper route money in the mid-70’s (I’m 63 now). It’s in excellent condition and I still have the owners manual…wish I’d saved the box. The amp works perfectly but I suspect is overdue for caps/bias adjustment, cleaning, etc. The cover has never been off.

I do not have the knowledge or skill to attempt it myself. Looking for quality service recommendations ideally in the Atlanta area. I prefer not to ship it if possible. Appreciate any guidance.

-Mike (first post on DIY)

Thinking of something like this (see below)

But in my case

• the front fascia is made of wood
• the top, bottom and rear are made of aluminum plates
• 2 heatsinks attached to an aluminum plate make up each of the side
• L brackets to attach each piece to each other

Feedback? Perhaps you have a better idea?

thanks in advance

I'm trying to pick a bass driver for a "micro-Manzinita" and I can't make heads or tails of the data I'm getting from the manufacturer vs out of Basta. I'm looking at the Goldwood GW-212/4 (1.2 Qts, black on the charts) & 12PC-4 (~0.4 Qts, red on the charts).

Here's the manuf data overlaid (in a 10 cu ft box):


Here's Basta data in a big box:


And here's Basta data on the 0.5x0.5m open baffle I'm planning (I will high pass around 200Hz or so):


What am I missing about the manufacturer's data? I will prob just get the GW-212/4 and call it a day.

For sale:
A pair of Altec 605B speakers in Onken 360l cabinets with Duelund CAST crossover.

2x Altec 605B coaxiale drivers with AlNiCo magnets and Markus Klug wooden horns (original horns included). 97dB/1W/1m
2x Onken 360l cabinets in Nantex
2x crossovers with Duelund CAST capacitors and coils, Pathaudio resistors, ETI research speaker posts.
2x Duelund CAST inductor 2.2mH
2x Duelund CAST PP 20uF + 0,01uf silver bypass capacitor
2x Duelund CAST Copper 12uF
2x Duelund CAST Copper 1uF
4x PathAudio resistors All cabling (crossover+internal) Duelund DCA16GA

High efficient speaker set, that's equally at home in small and larger rooms.

SOLD

ロシアの真空管6C33Cを使ってOTLアンプを作りたいです。それを行うための最良の方法は何ですか?また、例はありますか?

Just curious if there is anything in the construction (cone material, surrounds, etc.) added to mobile drivers specifically meant to deal with dust, temperature extremes, etc? Or will "home" drivers fare just as well?

Has anyone heard of Goldwood brand speakers? They appear in the PartsExpress catalog, and they were the only 4 ohm 5.25" speakers that I could find. They also sell for 8.95 so I'm skeptical, but if they can sound good in a car, I'm willing to buy them, if anyone has experience with it. At Madisound I've found 4 ohm Vifa speakers, that come at a heftier $57 per speaker, and also a $27 speaker. Any input on which one I should rather buy for a car audio setup? Am I looking for woofers, or midrange, or midbass? Not midbass I believe, and I will match these with a tweeter. How would I setup a crossover network for example how do I know how many Farads/Voltage for the capacitor I will need to use? I noticed that they usually cut the midrange? at around 3500 Hz. I'm trying to build a diy car audio setup. Any input is appreciated.

After building and listening to the Nelson Pass B1 Korg preamp and comparing it to the Pete Millett's Nutube Buffer preamp, I found I liked the sound of Nelson's Korg tube setup a bit better. I figured out how to make Pete's Buffer sound more like Nelson's B1 Korg and then it was onward to the NuHybrid headphone amp.

Not obvious is that all 3 circuit designs invert the signal. This happens at the NuTube itself. This is easy to correct with loudspeakers by reversing the loudspeaker/amplifier connection wiring but not easy with headphones unless you want to take them apart and rewire them. Listening tests confirmed that I preferred the correct polarity with loudspeakers, so I decided to try adding input transformers with reversed primaries to the NuHybrid to correct that circuit and see how it sounded. i did not want output transformers since the circuit was going to be driving headphones, not a high impedance.

I first experimented with some inexpensive Triad TY-250P transformers I had had kicking around just for evaluation purposes. Imaging was very much improved but their lack of shielding, excessive phase shift in the low bass and higher THD proved unacceptable. I ended up purchasing and installing a pair of Jensen JT-11P-1 1:1 high quality line input transformers and installing them with the primary winding connections reversed.

Here is what I did to modify the NuHybrid Headphone amp to compensate for the polarity inversion and to have it sound more like the Pass B1 Korg. The build was done in a DIYaudio Galaxy chassis with all jacks, power switch, LED and volume pot mounted off the PCB and on the chassis panels.

1. The Jensen input leads are configured as unshielded twisted pairs connected directly to the isolated RCA input jacks. Input polarity is reversed with respect to the transformer output. The RCA jack shells (grounds) are tied together and connected to circuit ground to eliminate hum when a source is connected. The output leads of the transformers are configured as unshielded twisted pairs and connected directly to the volume pot inputs. The transformer can shields and internal electrostatic shields are connected to circuit ground at the input side of the board. I provided a direct chassis ground connection at that point a with the series resistor/cap to chassis ground connection shown in the Jensen data sheet. A dedicated ground wire was run from the volume pot ground terminals to circuit ground at the input side of the board. Since I was using a 10K pot, the Jensen data sheet damping network was not required. Even though my pot is an Alps RK27, it has excessive noise at the extreme CCW rotation, which seems to be a problem with 10K pots in general. If I end up changing it to something like a 50K, I'll add the recommended damping network.

2. I bypassed the on-board PCB volume pot connections altogether and went straight from the pot to some slightly larger Kemet 220 nF input caps that were then connected to the PCB at the C20 and C21 locations. Shielded coax connections from the pot to the caps input sides are grounded only at the PCB end.

3. I changed the NuTube plate resistors R13 and R14 to 332K.

4. I set the plate voltage at TP1 and TP2 to about +9.75 volts. I found this is best adjusted while listening to music and set to your preference. I also found that anything over +10.5 volts made the magic go away.

So how does it sound? With the resistor and plate voltage mods, I think it sounds better than the stock 475K plate resistors with voltage set closer to half-supply. Smoother, with no loss of dynamics or detail. Correcting the signal polarity with the transformers made a very significant improvement in detail and imaging. Yes, they cost as much as the PCB, tube and board components combined but once you hear the difference, there is no going back.

I have two versions of these available. The first is a single rail positive PSU and the second is a dual rail PSU providing positive and negative outputs.

I have done a full write up on the single rail board here.

The single rail PSU is ideal for building into enclosures as stand alone power supplies for headphone amps, DACs and pre-amps.

The dual rail PSU is good for building projects that require both a positive and negative supply which you can house all together in the same enclosure. For example I have had a lot of interest in this board for use with Wayne Colburns BA2018 Linestage amp which is quite fitting as after all these PSUs are based in part on the Whammy PSU. I will do a full write up on my site once I get more boards from the fab house hopefully with the correct silkscreen and no lines. 🙂

I did my own measurements too with the scope to verify the boards I made are just as effective as Wayne's original design and the readings speak for themselves.

And for anyone that says "why are you using those old noisy regulators?" I added a smoothing cap on the output of the regulator and measured the output with the scope and I can confirm the ripple is just as straight as it is on the 3rd cap in the main filter.

Excuse the lines on the dual rail PCB the fab house messed up somehow with the silkscreen when trying to draw the caps on.

I have plenty of boards so if you are interested then drop me a PM. 🙂

It looks like GRS has picked up the technology of the B&G Neo line of planar drivers and Parts Express is now selling them. This is a great time to revisit what you might make out of this line of drivers. Here are some thoughts about how to best use the largest member of the lineup as a dipole midrange.

I've always wanted to get my hands on the Neo10 but never quite did, but have just ordered a pair of the GRS PT5010. It seems to be an almost exact clone, at least visually. I took a look at the response plot that GRS provides in the datasheet to get some clues about how I can best use this driver. I like to build dipole loudspeakers, and the PT5010 can potentially work as a midrange. I assume the response that GRS is providing in the datasheet is with infinite baffle loading:

I was hoping to cross over to it around 700 to 800 Hz, but the response is starting to sag there, with the SPL dropping down to under 90dB/W (the driver is rated at a nominal 94dB@2.83V).


To get a sense of what I might expect in a baffle of anything from zero (nude) to as large as I want to go I used the Edge to simulate some responses at a few angle up to 45deg off axis. I thought I would share what I found, which I think is indicative of how many drivers in planar baffles will behave as you vary the baffle size. Keep in mind that this is only the response of the baffle - you have to add it to what the response of the driver will be, e.g. its nearfield response. For that I will use the MFG curve for now until I can measure it myself.

First, let's look at the "no baffle" or "nude" response. It looks like this:

This has a very smooth response. The curves all follow each other, with only a bit of narrowing above 1.5 to 2k Hz. I would call this "CD like". There is very little sign of a classic "dipole peak". But since the low frequencies start to roll off just about 1kHz using the driver like this would only add to the downsloping response based on the MFG data.

OK, since I was planning to build a "slim" dipole system, how would the driver look in my narrow baffle? I tried out a 36" high, 10" wide baffle with the top edge of the driver at the top edge of the baffle. This what that looks like:

We can see that even this slim baffle has changed the response quite a bit. Now the response has a broad hump in it, centered around 1kHz. The result is that the response below that point has been brought up by a few dB. This would help to offset the losses from the driver in that region. OK, good so far.

Maybe we can do some of that same thing, but more of it, by using a wider baffle. Let's try going up to 15" W with the same baffle height and top-center driver position. Here is what that looks like:

Indeed, the response down to 500Hz has been brought up a bit more. But there is a new feature - a pinching and even crossing of some of the responses around 1.7kHz. This is exactly what you get when you use a baffle that is more than about twice the width of a driver and has been pretty well documented. It's not desirable to have this kind of response feature, because there is no way to correct for it in the crossover. This happened just by increasing the baffle width by a few more inches!

In fact, if you move the driver location to smack in the middle (horizontally and vertically centered) of the baffle, you will almost always get this kind of behavior:

Now the low frequency is well supported by the baffle, but the trouble spot remains, here at around 1.5kHz. It would be fine for a woofer but not for a midrange. This is why I feel that many wide baffle OB systems have built in problems. For instance the classic woofer plus fullranger in a large baffle - it is building in response issues that you cannot get rid of. Some of the Pure Audio Project systems come to mind, for example.

Usually I aim to implement a driver with as little a baffle as possible. As a result, some of my speaker systems are just drivers hung by wires. But that insures the driver responses are as smooth and CD like as possible.

But for this large planar driver it seems that the 10" wide baffle will work great. I hope to use it with a pair of 8" woofers below and a planar tweeter (probably the new GRS one) above, probably nude. It will also be visually "thin" which is helpful for dipole systems because the baffle will not block or interfere with the rear output, which you want to be able to let though so it can form that wonderful open soundstage that a good dipole system is known for.

This device was sent to me to fit a power supply and test basic functionality. However the owner pulled out and left the device.

It sure needs a revision which I won’t do as I don’t have a use for it.

It has a good reputation apparently. For the handy person that wants a classic mixer and is not afraid to do some work.

Only shipping within the EU. Offer me a price via PM if you want it.

Can anyone explain why the direction of d1 and d2 diodes is opposite in these simple circuits? Thanks.

Gentlemen

since a long time I am looking for a small mixer suiting my needs: 2 Stereo Channel input, 2 Stereo channel output which are easily switchable. The requirement came from the fact that I often do A-B tests, either comparing 2 sources to one amp, or one source to two amps to compare amps. It is not for DJ use.
As I did not find something which totally suits, I tried to come up with my own design.

• Sliders pots for the input and the output
• good sound performance
• small form factor
• Analogue-like VU meters using an Arduino and two small OLED
• Possibility to have a Bluetooth receiver connected, having a rotary volume and which can be switched off using a switch
• two clip leds, also powered by the arduino nano.
• All parts on the PCB

The "software side" is under control, but I am not really an expert in hardware design. Is there an expert who could take a look on the schematics ? Are there any major bugs ?
As a small thanks I would offer two PCB's to the one who could help.

I designed the schematics in EASYEDA Pro, the PCB is not routed yet but the places of the potentiometers, input rca jacks, vu meter is kind of "given".

Inputs will be highly appreciated.
All the best,
Christoph

Good day all,

I have a Concept 16.5,

Great old receiver, I love it. Recently a problem has been occurring. The volume can be at ANY level, low, medium, or loud. All of a sudden I get a quick and very loud buzzing sound over the speakers(less than 1 second long). The receiver then kicks into protection right away, then it kicks back out of protection mode(maybe 3-4 seconds it sits in protection) and continues to play the tunes like nothing has ever happened. Other than this the receiver has absolutely no background noise or hum, the bass is so tight and defined it's unreal, this receiver makes an old set of 30 watt hitachi's sound like gold.

I made sure all connections, grounds etc are tight inside, ridded of the dust, quadruple checked my speaker connections etc.

So does anyone have any insight as to why this might be happening? Some extra info before I bring it down to the repair shop would be great.

Also any info on Concept gear in canada? i'm in Northern Ontario, had never seen any Concept gear until I found the 16.5, which would have went to the dump the very next day. Been enjoying it for a while.

Sometimes the problem occurs after a day, sometimes it takes 1-2 weeks to happen....

Thanks and have a great day!

Hi Folks.

Could you help me with some information please. I have a Pioneer SA-9100 amplifier bought and kept by me since 1973. It needs work to restore it to better performance.
I am in Canada (east coast) and I would like your recommendations on who does this kind of restoration work here, and their reputation.

I don't know what is the proper place to post this, so please excuse me and move it to the proper thread if need be.
Sincere thanks in advance.
Randolph

Powered, active crossover, open baffle, coaxial.

Will it be amazing???

As if there was any doubt about price gouging and the ongoing speculations (rather than inventory crisis), here's an infuriating example:

Two months apart, Dec 2021 vs. Feb. 2022, while the semi "crisis" is ongoing. An about 228% price increase. This is from DigiKey and Mouser, not AliBaba or EBay.

Global market estimated at $28.5 billion in 2020. Are they talking about Hi Fi or Low Fi?

https://www.reportlinker.com/p05443560/Global-Home-Audio-Equipment-Industry.html

Interested in dml flat panel speakers. Have found alot of information and practical realistic design builds. Amplifydyi for ex. Bought an exciter 40 watt a Parts Express for under $30 total. Great company. Have been experimenting a bit with different materials and size. Attachment is also a big concern for unfunded vibration. One design attached the actual back of the excitor to a solid surface and had bad results. These panels I am using 1" pink foam board 2x2 feet hink poly styrene. Really vibrate visually and quite violently. Like long excursion sub woofer. I am thinking about using magnets to suspend panels via electromagnetic force so the vibrate ith out physical attachment. Any suggestions or input I would appreciate. I used springs and rubber bands. No test equipment so not sure if connection design is that important. Will try and combine a longer panel with smaller one for better bass. 2 excitors on one panel doesn't seem to work for videos. Trying a damaged dome tweeter with attached different small panels. No success yet at all..Any crazy out of the box ideas would be appreciated and maybe tried out. There is alot to his design that needs to be explorer. Michael

Hi guys can you recommend me some bluetooth amplifier module?
I got this on amazon ....



But it makes an exaggerated rustle and pops, at low volume the rustle almost covers the music.
Recommendations for modifying this sheet are welcome

thank you

Hi,

I am brand new to this forum. Please let me know if I'm violating any rules. I'm in the middle of my WHAMMY build and I am stalled due to missing/incorrect parts. I sent an email of to the diyaudiostore customer support.

In the meantime it seemed like the opportune time to ask a few questions about the build. I am building the stock version of the kit. Mine came with the AMVECO 12.5 VA + 12.5 VA/18 V + 18V transformer. I am using the red LEDs in the power supply section for reference voltage.

1) My op amp is labeled 458,000 JRC A133 A. I can't find the data sheet for it. Should I be using the optional 22uF/25V caps at C26 and C27 or should I jumper those pads? My understanding is that if this op amp is bipolar, I should use the caps.

2) In the build guide the shielded cable used for inputs/outputs has the shield connected at both ends....at the jacks and at the pcb. In all the preamps I have built I was advised to connect the shield at the jacks, but not at the pcb. Doing so, I was told, could induce ground loop hum. What should I be doing here?

3) I've read all the threads about wiring the panel mounted LED, but I'm still confused. A clear 5mm LED was supplied with my kit. Given the transformer I have at what specific pads on the pcb should the anode and cathode be attached? What value resistor should I attach in series with the anode? If after attaching the resistor I wish to lessen the brightness of the LED I could increase the size of the resistor, correct?

Thanks in advance,

John

Hello all, I have a Mackie M1400i power amp that was having many issues that have mostly been resolved, but found some rail voltage where it shouldn’t have been and it was due to a faulty 270pF silver mica.



So I plan to replace both C18 and C20 in both channels. What I have on hand are 330pF silver mica and 220pF and 330pF in both polypropylene and ceramic, not sure if dielectric matters here. Ultimately I’d like to swap in four 330pF silver micas, but want to make sure that increasing 60pF won’t cause an issue. I’m trying to save the $25-$30 I’d have to spend for four new silver mica and shipping costs.

Should I be okay with the 330pF mica or would be better to go down to a 220pF poly or ceramic?

Thank you,
Dan

I am looking for high quality replacement divers for 1980 ADS 1530’s
I need 4 high quality 10” woofers that can handle high and low volume power of about 200 watts from about 20hz to above 500hz
A midrange 4 “ from 500 to 2500hz and tweeters from about 2500 and up
I have been looking at scanspeak for the quality.
Any help would be great. My drivers got missed up by shippers.
Thanks

Hi guys I am trying to make DAC 6 channel converter using PT 8501 Ic anybody have complete datasheet or circuit schematic please post me it will helpful for make DAC for set top box cheap

2 X Matched pair of 2SJ618 / 2SK3497,

Bought as part of a job lot of components, most of which were originally bought from these forums.

£40 plus postage £4 UK £8 Europe £12 rest of world, will send royal mail signed for.

Yesterday i bought a karat MP-202 russian cassette deck at the flea market for like 2 dollars...it doesn't really work as some belts and idlers are worn , one resistor very hot...probably some regulator damage as well , but the overall design and transport left me breathless, especially one very ingenious feature around the capstan roller that can tilt , probably removing the posibility of chewing your tape even with a worn rubber roller, but i expect some feedback on that feature if it really works .I'll refrain myself telling more about the huge flywheel when i know russians also made some awesomely stuffed direct drive decks, but that looks impresive too and and the all metal-rubber belts and very simple yet efficient transport gave me a really solid feeling of something worth restoring and maybe looking for improving the electronics if needed as it only uses a DNL like type noise reducing system and just a universal tapehead, but maybe taking one of those transports and placing it into my favourite pioneer deck would be more interesting...Hopefully someone will help me with a schematic cause i can't find anything and i don't know how to look for rusian info.

Is anyone here using the CS8416 in "Software Mode"?
If so, I have some questions.

I have built a DAC board with the CS8416 and the MAX9850. I have the I2C bus working nicely (connected to a PIC 18F2550) and I can read/write commands to either chip. But, so far - the only sound output is a few clicks.

Please share your init sequence. Here is mine (function I2C_W2 writes 2 bytes on the I2C bus):

a) which of the 16 choices for GPOn best describes if the CS8416 is decoding a valid stream? I have tried the C (channel status) and NVERR, but they are always 0 (so far).

b) I have my CS8416 in Master Mode and the DAC in Slave Mode, does that make sense?

Thanks,
Jake

Hi all and thank you for the add.
I’m having trouble with setting the mid point voltage on the output caps.
I can’t seem to get the voltage any lower than 10v below the rail voltage of 67v.
One board is fine showing 33.5v the other is 57v.
Any help would be greatly appreciated.
Thanks in advance.

Somehow 😢 I've blown up a mid range driver on a 1984 B&W 801F speaker. I still don't know how I did it, but it has gone open circuit (well, about 1M) and has a very faint burning smell to it. The terminals are fine and I measured their resistance across the tinsell leads to make sure. This happened while the driver was tri-amped with a home constructed amplifier and I suspect that while I was testing different configurations of the amp earth wiring to minimise earth loop hum an output tranny has shorted and fried the speaker. The amp is fine. Base and tweeter are both fine, so it's a bit of a mystery and also a lesson to use a crappy old speaker when testing amplifiers.
What to do? Is such a fault repairable? Is there any other possible cause of these symptoms? Are there any drivers out there that would be a potential substitute for the original? I'm OK with soldering fiddly parts, but I doubt very much that my DIY skills would extend to voice coil winding.
I would dearly like to remedy this as the tri-amped 801s sounded absolutely heavenly.
Any advice very gratefully received.

Hello,

I have to make a class AB amplifier for high frequency applications (400 kHz - 700 kHz).
There is almost no literature in that frequency range so I started to learn about audio architectures to improve them.
I made a simple CFA schematic but I have not so much experience.
The amplifier has to deliver 15/20 W to a 20 ohm load (the load should be capacitive because is a piezotransducer).
Please give a look to my schematic to see if it shoud be ok or if there are little or big mistakes.
Any opinions to improve this design should be appreciate.

Not sure on the model number of this somce someone painted it at some point

Both channels have 4.50 volts measured directly across the speaker terminals .

I checked the outputs all test fine .

I’ve checked over a few other things diodes transistors resistors all test good .

Any ideas ?

Does anyone know where I can find a table to convert DbA to Db?

You would think it is on the WEB but maybe I am just not very good at surfing. I am NOT looking for an online program--I need the power/freq conversion table or curve fit for this.
(I have a power meter that only reads DbA and I need a make a curve of relative power to frequency do I need to convert DbA to dB)

Thanks!
Fritz

I am using stereo subwoofers with full range active 3-ways for the first time. The system is for music only, no movie effects. The subwoofer low pass is 70 Hz and is carefully phase aligned with the 3-ways woofer at this frequency. Should I install a woofer high pass at 70 Hz also? I realise this will save the woofer from exertion at low frequencies so it can possibly play cleaner in its pass band, but is there any downside? Is it preferable to avoid additional phase shifts caused by the extra crossover?

I don’t wanna post both amps in the same thread to make things confusing.

Anyway I have another 17k amp here that was installed in the system when they used amp scope and blew 2 of the amps up the 3rd amp has issues also .

So the 2nd amp in the system which I have in front of me the owner states that it has Terrible feedback . He stated when powering the amp down it sounds like a vacuum cleaner turning off . Also when the amp is powered up there is a loud hum through the subs .

He checked the rca shield ground in the head unit which are fine also installed another amp in the vehicle and it has no issues so it narrows it down to this amp .

Any ideas on what to check or where to start since everything is testing fine so far

Hi,

together with my best friend I'm going to build a pair of Silbury speakers (but same applies to many other speakers) and I opened this thread to have confirmations that what I'm doing is correct, and information on how to properly do things. I'm reading this very interesting site: http://www.troelsgravesen.dk/ full of information, and indeed together with my friend we did a similar tool to drill holes.

By now we have tried to drill the holes in two steps on some samples of wood before drilling the wood dedicated for the speakers:
The rear chamfer has been done with this tool: https://m.media-amazon.com/images/I/51YyV9z+E4L._AC_SL1000_.jpg
The front hole has been done with this tool: https://m.media-amazon.com/images/I/61QI3Mab-iL._AC_SL1500_.jpg
The hole has been done by a tool similar to this one fixed to the milling machine: http://www.troelsgravesen.dk/tips/bb.jpg

I would like not to cut the big curve freehand, so I would like to ask if there's something I can build to properly cut the curve.

The third point is how to chamfer the sides of the speaker: is it needed to use again the milling machine with a tool like this one: https://m.media-amazon.com/images/I/41f3FpwBAML._AC_SL1000_.jpg or the saw incluned by 45°? How deep the chamfer must be on the side of the speaker?

Thank you in advance,

Roberto

Hi,

Any one can advice what the suitable OPT (push pull) for GU-50 wired as triode @ Vp ~ 300-350V 80-100ma per side?

Some one also offer me 2 choices: 4.6K p-p with UL tab, -vs- 6.6K p-p with cathode feedback (originally for QUAD Kt88 clone amp, no UL), and wondering which one can be use?

Thanks.

Hi, Does anyone knows how to open top vent cover on ML 5302 power amp? I don't see any screws /// I see bunch of hex screws on top portion of both heat sinks but not to sure they are connected to the top cover. Or is it just pop on and off maybe? thanks

I got 4 tubes like this one, marking gone. Looking on the Internet the PCL82 seems to be the best match. Can anybody help confirming?
Thank you!
Jose

This project is inspired by the wonderful headphone amp by mediatechnology using a THAT1646 line driver in a novel way.
https://www.diyaudio.com/community/threads/simple-class-a-headphone-amp-using-that1646.163544/

You can buy the "Dual Class-A II Output" (DCAO2)" headphone amp here
https://ka-electronics.com/shop/index.php?route=product/product&product_id=67

This new project aims to design a small mono SMD version of the above amplifier in a balanced bridge configuration.

In addtion I will add a small signal peak detect to drive an external LED and maybe a delayed power-up to the opamp power rails to prevent power-on damage to the phones. First draft incoming.

Hey guys,
Have any of you wandered across any compactrons suitable (or equivalent to another) for use as an output tube? I see a few here and there, but there aren't any curves for them. There are also some with fairly decent looking pentodes in them and an associated triode/diode. I wouldn't mind using the pentode only section I suppose.

I would like to stay with 12 or 6 volt heaters, and also the 6T9 is not beefy enough.

For sale 2 x Nos quad matched tubes. One quad 5933 Sylvania and one quad 807 Westinghouse. So total 8 tubes in Nos condition. Price 100 euro plus 12,90 euro insured shipping inside EU.

Hello , I'm looking for 2pcs (or just one) Peerless-Vifa-PL22WR-09-08 8" woofer ?

We are currently hosted with Linode (Dallas TX Datacenter), and they had a few hours of issues which affected our site just now. The issue appears to be resolved now.

Hello. Can anyone help with how to modify the input sensitivity of a Linn LK85 so that it works better directly connecting to a Chromecast Audio?

The LK85 has an input sensitivity of 685mV whereas the Chromecast output is 2V. There is a LK85 schematic here, could it be as simple as changing R106/R107?

Rockford Fosgate 500X, PC-3084B. Rebuilt channels 1, 2, & 3. Everything appears to be good, but with the input switch on 2 channel input, 3 & 4 emit white noise with either no input connected, or in addition to input. There's no noise from 3/4 with input switch on 4ch and 3/4 produce clean output. Channels 1/2 never have any noise regardless of switch position, and switch seems to be fine (cleaned with deoxit as well).

How is it picking up noise if it's getting signal from 1/2 which have no noise?

I have come through 2 formulas for leveling port spl to match nearfield spl.
1. 20log(port diameter/ eff diameter of cone)
2. 20 log(port area/eff diameter of cone)
That makes quite a lot of difference.
What is the correct one?
Any

Hi,

I'm looking for curves of a triode-strapped E180F/6688.
Can any of you guys help me ?

Thanks
Jim

Looks like an interesting book, pics of sliced-up parts, first chapter "Passive Components" is a free PDF.
https://nostarch.com/open-circuits

I just completed the full kit earlier this evening. I've been playing with bias everywhere from 9.5V to 13V. I think I prefer 13V. Is 13V safe and stable and conducive to longevity? How high can you bias this preamp safely?

Vertical heatsinks on amplifier PCBs are a weakness since they dissipate heat poorly especially in a wide low chassis with insufficient ventilation. See in the attached photos where the NAD C320 is only partially vented on the top and even less on the bottom. The output stage has it's own shrouded heatsink which is slightly warm. The driver stage with the vertical sinks is somewhat hot. These two sections are under the vents. But the 18vdc discrete regulators are finger-burners. There are tiny holes in the PCB beside the regulator heatsinks which I suppose is intended to allow a wee bit of air to convection cool the heatsinks. Huh?

The C320 worked perfectly for thousands of hours until it began varying the audio volume intermittently. Such problems are difficult to troubleshoot. I need to fix it or visit the recycling depot. There are no obvious bad components but the internal heat dome is suspect.

In addition to poor ventilation, the input voltage to the regulators is excessive (38vdc for 18vdc out). This is probably a design choice to work with the toroid which has only two secondaries. One is tapped to produce 38v and 48v, the other is low-voltage for a 7805. So the 38vdc remains. I decided to install a custom pre-regulator for that. It reduces the regulator P=ExI value from 2.4 watts to 0.72 and relocates 1.68watts to the chassis metal on the mainboard perimeter. The amp works fine with 24vdc, not 38vdc, driving the regulator.

There is an option for additional cooling. Place a tiny 12vdc fan on the chassis cover such that it blows across the vented area. This is effective since it creates low pressure over the chassis and draws out some heat.

If you are interested in below merchandise, PM me with your address, and I will reply with shipping quote. I ship small packet, insured, no tracking, unless stipulated. I have shipped all over the world with no problems.

1. Dx Super A amp & Dx PSU. PCB's from Juan Vargas and Carlos FM (Desroyer X). 2 sets available, each set has 2 amp boards and 1 psu board.
Photo is 1st one. Price is $30 USD per set.

2. DLH - Trilogy amp. PCB's from Horacio and Prasi. I have 9 boards.
Price is $3 USD per board. Photo is 2nd one.

3. LM4780 Classix Kit from Peter Daniels. Never opened.
Price is $50 USD. Photo 3rd one.

4. Partial built LM3875. Peter Daniels kit. Powered one channel before, but sold the transformers. Price is $25 as shown. Bypass caps on bottom of pcb. May have some caps laying around to include. Photo 4th one.

5. PSU for Chip amps from Mark Johnson. I have 3 board. Price is $2 USD per board. Photo is 5th one. Sold

6. Dual Rail SLB / Active Rect / CRC / CapMx / Class A PSU pcb from xrk971 / AKSA / JPS. I have 1 of these. Price is $15 USD. Photo is 6th one. Sold

7. Cap Mx from Analog Designs/Prasi. I have 10 boards. Price is $5 USD per board. Photo is 7th one. Sold 4 boards, 6 left for sale

8. CRCRC pcb from Analog design / Prasi. I have 2 boards. Price is $5 USD per board. Photo is 8th one. Sold

9. LT4320 active rectifier boards from Analog designs / Prasi. The boards are THT and I have 8 boards. There is 4 rectifiers per board. Price per board is $6USD. Photo is 9th one. Sold

10. LT4320 ideal rectifier boards from Analog designs / Prasi. The boards are SMD and I have 5 boards. There is 4 rectifiers per board. Price per board is $4 USD per board. Photo is the 10th one. Sold


Thanks for you interest,

Myles

Hi guys. I'm a beginner, I've built three amps and they all turned out great. Which was really encouraging with the hobby.

I'm planning two new builds. First is PTP wired gainclone monoblocks using LM3886. Second is an A/B mosfet 250w per channel power amp.

Basically I'm curious about bass. Within the design confines of minimal power amps such as these, what provides good bass? Someone told me that it's a combination of using an oversized transformer and quality power caps. But as I'm a beginner I'd like to ask you guys! Thanks!

So.. I have this idea that keeps tickling the back of my mind about making a customised speaker driver and offering it for the DIY market. I think I can see a little niche, but do not want to blab about it yet when I have not even done a prototype. Please bare with me!

To do this I would need to create my own surround for the cone and I was wondering what the differences are between foam and rubber? Anyone got experience with driver design?

Perhaps does foam hit its excursion limits more gently than rubber, my assumption is that it can stretch a little more?

It might be my imagination but I feel I've seen more foam surrounds used in car audio and probably more in subs than midrange for example?

What do you know? 🙂

Hi, I have upgraded Denon DVD-A1 (8x pcm1704 , Alpha 24 procesosor, spdi freceiver input) a Mark levinson no360s analog IV stage is built in.
sound is much worse than Mark Levinon No360s DAC using same dac chips and same DAC IV I thought it was power suply (no360s uses discrete) so I put complete no360s DAC/IV boards to DVD-A1. to my surpise is still sounded much worse than No360s. now it was only the digital front end diferencies.

I looked deeper in the schematics of DVD-A1 and see that I2s doesn’t go from DIR to AL24 chip. instead of that it goes trought few DSP chips –DVD processor chip ES6038, and ADSPMEL322. so I connected i2s lines from DIR directly to AL24 chip and bingo- good sound at last.

I make micro small swithches near rj45 jack (denon link jack whch is perfectf or i2s input which I will add, remooved two chips to have this jack free from any conections)

now is problem with comutation. I do not want loose cd-dvd source. dvd-a1 have 3 source selector switch- DVD/Optical/Spdif I need this- WHEN DVD position is set relays are eneergized and i2s line ir connected ( or maybe is more elegant decisions) I am not familiar with micrcontrolers. How to get signal from it to relays to be energized when dvd rotaty position is set? thanks in advance.

Hello all,
I've been buying parts to complete my AudioSector LM4780 boards but the BOM info online is a little lacking. I have all the parts soldered up (including 0.5W resistors instead of the 0.25W resistors that would actually fit on the board) except for Cz. I see it's a 0.1uF capacitor, but what voltage rating is required for this? I can't find the info anywhere, it's not even listed as included in the kit from AudioSector

Thanks!

Located in Carlsbad, CA 92010 for free pickup. I work down in San Diego and can meet there during my lunch break if needed.
There are eight Philips ones and five Mallory ones. They are 3" in diameter and maybe 5 or 6 inches tall.
I also have 8 of the 3" mounting clamps.
These haven't been re-formed in about 10 years.

I want to build horn bass speaker for my system. I have Dallas II with Fostex FE206EN and Monocor compresion super tweeters,playing trough KT88 SE amp.
Everything works nice,but im lacking deep and powerfull,clean bass. So i want to build bass horn.
I buy Eminence Kappa_Pro_18LF_8 and now i want to build a cabinet.
I have problem with space but i want to have nice horn bass sound,not vented box sound.
And i dont have much space. Worst thing is that i dont have enough deepnes for all design what i can find online.
So,i start to make design,change it 1000 times,and in the end,re-scale Klipschorn inside mesurments and put everything together and now i have some design which look ok.Looks,i dont know how this will sound and how low can i go whit this,is it ok for frequencis below 150 hz,etc.
I dont know how to calculate this design to see where is good and where is bad,do i need to change something...So here i humble asking for good souls who know how to put all parameters into calculator and calculate it for me so we can see where to go whit design.
I have to amps for this project,so i will see wich works better,one is digital 150W 8 Ohm,other is solid state 500W 8 Ohm,i take signal from speaker wire and cut it with active crossover at 150 Hz.
Here are pictures of design.

https://www.tinyosshop.com/index.php?route=product/product&product_id=1151

https://www.audiophonics.fr/en/blue...er-board-qcc3031-aptx-hd-tws-ufl-p-16868.html

There seems to be a dearth of information on practical ways of current driving loudspeakers, though I think I have looked at all that is available from Hawksford to "The natural way of driving loudspeakers". What is clear is that you get 20dB or more of reduction in distortion, quite apart from the distraction of thermal compression.

I have an idea of putting a capacitor in series with the "current sense" resistor, so as to roll off the current drive when it approaches the fundamental resonance of the system, and thus have the nice predicable voltage drive through that region and not, there, be affected by the change in impedance. But otherwise have current drive above there, even though that would mean a rising response with impedance.

It seems to me that the capacitor would only have to be a few hundred uF, so not fall into the trap of real power capacitors, but yet be quite good in that the ESR will have fallen to about as low as it gets for any electrolytic. Although this isn't the topology I think I would like to use in the end, though I'm not quite sure what that is right now, it nevertheless encapsulates the idea in a simple form.

I am well aware of the dependency on impedance that this whole thing implies, but was wondering if anyone thought this was a bad idea in principle. The idea is simply a transition from current drive to voltage drive when we get to the point that matters. (And incidentally I don't think I believe the very generously smooth curves that Nelson Pass published in his study of various Fostex and Lowther units with a high impedance drive. I think a very much more real peak should be apparent in measurements; and one that reflects the transition from a Q of 0.7 to a Q of perhaps 3 or 5, which is what it would be without electromagnetic damping.)

Incidentally, but quite pertinently, I don't like chucking away perfectly good signal in a power resistor, so bright ideas of how not to do that, but do the same thing more efficiently would be amazingly welcomed.

Maybe a stupid question
But how about driving difficult tubes like 845 with a high voltage op-amp?
Yes I see that the opamp costs the same as a nice interstage transformer.

https://docs.rs-online.com/080a/0900766b80ef3d69.pdf

I I'm selling last 4pcb of excellent OME SIGMA-IV lateral mosfet audio reference power amplifier.

PCB Specifications:

• 70um copper (2oz)
• 1.6mm pcb thickness
• red solder mask
• white silkscreen
• hasl pads
• pcb drilled

For price and shipping cost please send PM and your country. Payment will be with paypal.
After payment PCB Boards will be send next day with tracking number.

Here is picture of boards and schematic:

Hi everyone, I've been looking for a reference or an article about formulas and calculations on the 6th order Sallen-Key Butterworth high-pass filter in "two stages" but I couldn't find anything. As you can see this is the Rod Elliott's 6th order Sallen-Key design but there is no explanation on how the calculations are. I've also checked out the Doug Self's book and found nothing. Any help will be appreciated.

I have been working on this project for years and I think that it is finished. Here is a Schematic of one Channel and a populated board showing the layout. It is typically designed for a 12V, 5A wall wart current limited power supply. It has low noise and low distortion but it has not been measured. It has 2 gain options of 3x and 24x through 2 RCA inputs. One channel oscillates near 300 Khz while the other channel oscillates near 250 Khz. The output stage features low crossover distortion because of its zero dead time design. It consumes about 2 Watts of standby power because of the bias in the output stage. The discrete nature of the design allows a hobbyist to use better op-amps and bigger output Mosfets and different dead times to change the noise level and the distortion level of the amplifier. The purpose of the design was to get low distortion power while using no heat sinks. Eighteen Watts of power per channel is relatively small in the class D world but that makes it affordable and 18W of power can be quite loud when applied to efficient speakers.

??Markaudio????8?CHR120??HiFi??????????-???

just saw in China Taobao webpage, Do you think is it better than alpair12 previous model?

I'm still trying to create my ideal desktop system. I have an 8" sub at my feet - it's brilliant, no complaints. What I'm trying to achieve is a system that still sounds acceptable with the sub switched off (neighbours, party wall). I had a pair of Sony SS-CPX1 on my desk - it was all working. But then I bought a pair of Goodmans HT-97s for £2. Bigger driver, bigger cabinet . . . more bass, right?
No. The Sonys (top) produce more bass but the Goodmans tweeters are loud and harsh but sweet. I'll guess 5 or 6 dB above the Sonys - my ears are ringing. These are very old speakers. Could it be a cross-over issue?
I'm minded to put the Goodmans tweeters in the Sonys and ditch the rest. But I don't want to be told that HT-97s were really great speakers back in the day . . . and I just threw a pair in a skip.

I am wondering how to proceed to get the correct port measurement in a 2.5 way. Both upper and lower drivers are needed to simultaneously produce the correct tuning frequency, but when one driver is disconnected and I take a measurement on one driver only , I get a queer port bump as can be seen in the 2nd pic.
1st pic is the normal measurement with both drivers connected.
My aim is to get the correct measurements procedure in view to merge port and nearfield for merging in the first instance and then get the farfield and finalising them all into a quasi-anechoic FRD for xover purposes. Can anyone help? I did not find the solution on the forum.

Im making a very basic MTM center speaker. Using Two 4ohm 6.5" midrange in series with an 8ohm tweeter. two questions



1) 1st order low pass I assume I treat the pair of 4ohm mids in series as a single 8ohm woofer?
ie: single 0.2mh inductor before the 2 mids in series. for ~6300hz cross (not a 0.1mh before each woofer)



2)For design Its being built into the tv stand.
I have upto 26" width, 13" height, 18" depth for the center. Should the tweeter go above the mids, or tweeter mounted inline as high as possible?

From all outward appearances the practice of installing a cap of a higher rated voltage seems to be acceptable, especially if you are not deviating from the original values too much. I have done it with small caps as I am sure much of you have as well. Increasing capacitance is something I have not done though. I know changing capacitance can have adverse affects on the sound chain but I would hope that increases in the capacitance of the main power supply caps would do no harm and could possibly do some good.

I have looked at some engineering sites and in most cases those writing on the topic would accept this practice as long as the replacement values were not ridiculous and always greater, never lower.

I am working on a very crusty SAE A202. It is tired and I just want to give it a second life. I have done a similar rebuild on a 502 and was delighted with the final outcome.

Like the A502, the 202 uses odd-ball size caps which are not available and have no direct replacement due to the space constraints. The A202 uses 63v, 10000uf caps. I will not be able to source those. However I have new 502 caps that are rated at 80v 15000uf. The 502 cap is taller but the diameter and triple pin connections are identical. I installed these larger caps in the A202 with only the need to notch a bracket to make room for the additional height. I have not powered it up yet. It is in pieces as I wait for a shipment of smaller signal caps.

So my ultimate question is, does anyone see a problem with the increased capacitance put into this circuit? My instinct tells me it will be okay. I am already fully committed to the idea as I have performed the swap but since I have yet to power it up I cannot really tell what the outcome will be. I would like to bounce this off of some of the more technically savvy folks here. There may some part of the science of capacitance I am missing here. I once learned this when omitting snubber caps in a motor control circuit. Some of the math is above my head 🙂

Here is before and after:

ORIGINAL CAPS


SIZE COMPARISON


BRACKET MODDED & NEW CAPS INSTALLED


Thanks for the insight.

I'm getting pretty close to completing my first high voltage(450V) tube amp but I am struggling with the PSU.

I have a 230:355V CT power transformer hooked up to a full bridge rectifier(CT not utilised) feeding into 1500uF of caps through a 10ohm for current limiting and then an RC filter that also drops the voltage to the 450V I need for my design.

The problem is that the transformer is giving me about 600V after the rectifier because I am not loading it much(only drawing about 5mA at the most, transformer secondary specced at 130mA). This isn't a huge issue for the tubes but the caps I am using won't survive that for long.

So far I have tried putting a 100V zener in series but they short instantly when I plug in the power because of the massive inrush current.

I am not really sure how to fix this besides loading the transformer more with power resistors or light bulbs or something. I was looking at maybe using a stabiliser tube instead of the zener but then I read that any capacitance over a few hundred nF would cause it to oscillate so I don't think that would work either...

Maybe I should just beef up the inrush resistor a bunch?

Thanks for any help 🙂

Hi,

My Marantz SR7013 have begun to shut off with a bang due to DC current offset.

To troubleshoot I have disconnected everything and measured all the different speaker terminals with a multimeter on 200mv.

I measure around 0,02 – 5,1 mv, and everything seems fairly steady until it shuts off and the meter goes wild for a second.

I have tried this before in September and after shutting off and shutting off it worked again for now 2 months.

Do anyone have any ideas on what could be causing this?

Br,

Zillo