What causes colour clashes? Do we all perceive the same colours clashing?

Struggling with home decorating started me thinking about this! I'm seeking a more profound understanding so I can finish painting.

Why would certain colours on the spectrum from red to violet look discordant? Like orange and blue? And others not discordant like blue and green?

Is there a mathematical basis?
Is it evolutionary...some combos occur in nature and signify things to stay clear of?
Or does everything actually "clash" except we tolerate combos that we are used to seeing in nature, like blue sky against green grass?
Or something else?


Insights invited.

Hi there...

I am going to build some bookshelf sized 2way or 3way speakers (and a sub)...

I have found out most of the build but "the most important" the size/design of the speakers is missing since I cant find my old software in my files...

I have just searched a bit online and I can only find expensive very advanced programs...
Right now I am hoping someone can recommend something very simple to use straight forward software... I do think I found for the sub but any recommendation is very welcome 👍

Hi everyone.
I found this page online, it's in Italian but just use the translator.
on this page an empty tube is used but nothing prevents you from taking the measurement with a tube filled with fibre. In your opinion, is it possible to use this method to indirectly obtain the exact length of a folded TL?.
Let me explain better, first step, take a measurement on a tube with a purely random length but calculated section. second step, once the exact value of the tube's resonance frequency has been obtained, it is possible to trace the length of the TL which corresponds to the FS of the speaker you want to use and thus build the TL with the right measurements.
what do you think?.hi thanks

https://farelaboratorio.accademiadellescienze.it/esperimenti/fisica/105

Hello - I have an Audio Research Ref75se (stereo) and I'm thinking about getting another one and using just one-channel in each amp. This will allow me to get the amps closer to the speakers and have backup components and tubes for the long run. I don't have a circuit diagram but I would think that removing the input tube and output tubes on the channel I'm not using would be fine. If there is a connector/fuse from the power supply for each channel that would also be disconnected. Anyone have experience/thoughts on this. Thanks

E.g. AC 3.75V-0V-3.75V
Fixed bias.

Hi, just joined, have enjoyed audio even before making my own bass-bin in the 1970s - never really got past the 1980s!

I want to measure a signal noise ratio (SNR) in an power amplifier. SNR is calculated by 20Log (Vs/Vn) when Vs is nominal output voltage in volt RMS when generate a nominal power and Vn is the noise in volt RMS (weightning A). Alternative metod is: nominal voltage output in dB minus noise (weightning A) in dB. I using the Focusrite Scarled 2i2 sound card with REW software.

An examples in my litle diy power amp.

Using attenuator from power amp to sound card.

1) set input knob to minimum in sound card
2) connect sound card output to the power amplifier (TS -> RCA)
3) connect LINE input of sound card to amp out via attenuator (-20dB)
4) gently ingrease output level untile the THR reach 1% (this is max power)
5) run SPL meter and set weightning Z and save the value displayed (101.3dB)

If you want using multimeter to measure maximum Vout of the amp, in my example is 16.5Vrms and calculate the nominal power Pnom= Vrms^2 / 8 = 34W (8ohm load)

6) calculate dBsignal: dBsignal = dBdisplayed + dBattenuator = 101.3 + 20 = 121.3dB
7) stop generator and set to zero monitor knob and read dBspl weightning A (21.2dB)
8) calculate SNR = dBsignal - dBnoise = 121.3 - 21.2 = 100.1dB

Isn't necessary calibrate level on sound card.
This methods are valid if your sound card has a high enough SNR. To check this simply disconnect the sound card input from the amplifier and short-circuit the input, the SPL value must be at least 10dB lower than the value read with the amplifier connected.

Hi, I have been searching for some considerable time for a (reputable!) frequency response curve chart for these - Vifa H25TG35-06 - tweeters...

Anyone out there got one they'd like to share / send to me?

I can find (and have) the H26TG35-06 charts, but simply can't seem to find one for the H25; there was one solitary old post here, back in 2008 - but it only mentioned having one, didn't actually post any chart it on here - there's plenty mention of the H25 in comments, but I can't find any charts...

I am attempting to get as close as possible to the "right" (what's right?- you may well ask!) replacements for the original 6-ohm tweeters in a pair of 1984 Mission 770 Freedom cabinets (mine arrived with some replacement name-/brand-less 100mm soft domes with the frequency response of a wet sponge!) ... I believe that some variant of these H25s was used in the Mission 780 / Argonaut, though perhaps it was a variant of the 6-ohm Vifa D25s used in the 770 Freedoms? - help!

Yet, even having fitted these H25s to the 770 Freedoms, despite their high sensitivity (needed, imho, to balance the cabinets' bass response), I am still finding them just a little "flat" and without the "Spatial" breadth of my Mission 717 speakers (which host Audax HD100D25s, but have decidedly inferior bass capabilities) - any help gratefully received! (though I am not going to get into any alterations to the cross-overs.. that's unfortunately just a bridge too far for me at the moment!)

Chris

I am in need of some LTZ-R17 LED Diodes used on the Amplifier Driver Board on a Yamaha P2250C Power Amplifier can't find any data I beleive this Diode is to indicate a fault issue
should there be a problem.

Thanks for your time and consideration

Hi, this is Maurizio from Rome. I have a general question about the measurement of T&S parameters. I happened to find an old 5" double coil fullrange loudspeaker, made by Siare french company. It's a veeeery old item, no marks, sign or info on it, apart of this text:
" 68145 8 Ohm
SIARE
2 04 86"
I was unable to find any further info about the speaker. The foam was destroyed, and I replaced it with some new I had handy on my desk; not a great job, but it seems to work fine. Now, I'd like to use the speaker for some future project, therefore my question is: what about the T&S paramethers? Should I measure them separately for the two channels, and consider the speaker as a couple of indipendent speakers, or is there any specificity I have to take intro account for the measurements? I think this info could be useful to those who want to recycle old double coil car speakers, too. Any hint from the members will be very appreciated. PS: please, forgive my basic english…

Hi, I’m a relative newbie from Hastings, UK. I’ve done the Skunkie mod on my Reisong A10, which went smoothly. Now I’m going to tackle a Nelson Pass Aleph J, and have just ordered the kit.
Looking for help and ways to get great sound for a great price!

Hello everybody !
Im Manol from Bulgaria .
Audio is my hobby from maybe
20 years.
I believe that these community will helping everybody to explore audio journey in all of its colors and shapes , and all together makes it even more interesting and plesand .
Cheers !

Wanted: Ayre K-5xe MP preamp (UK/EU voltage).

Anyone have one they want to move on?

Looking for one with the remote and the original box.

Thanks in advance.

🙂

Hi everyone.

I joined back in 2012 but forgot to say hello. Better late then never.

Been a big user of the site for advice and information, especially since acquiring 2 DIY builds, based on Soekris DAM1021 R2R DAC. Bought the first build in 2017 from a UK seller. The DAM1021 is rather special. And so found another good build, again from a UK seller in 2023 (I am patient).

Hi,
First post. Looking for DIY info.

Hello all members. I am Leandro from Argentina but have lived all over the world and currently living in Bangkok. Interested in restoring and tinkering with late 80s and 90s amps and speakers, anything interesting that sounds right. Hoping there are members brains here i can pick and share information.

Hello from Sussex, UK. I had a copy of LEAP5 which I used a lot until my laptop and dongle was pinched. I've been running a dodgy old copy since then but would really like to have the last version Chris produced. He even included some stuff I suggested! Does anyone have any leads to where I could find such a thing?

Has anyone tried the Dayton Audio KAB-2150 2 x 150W amp? I couldn't find reviews about it.
I would like to buy it, but I don't know whether it is worth it.
Here's the amp: https://www.parts-express.com/Dayto...rd-with-Tone-and-Volume-Co-325-501?quantity=1

I have a late 80s Yamha P-2250C Power Amplifier that uses a IDEC MSJU-24VDC for the output protection am looking for some relays to replace the ones I have the coil resistance is around 592 Ohms.

Would like to buy some if anyone has any.

Thjanks for your time and consideration

Dear Gents,
Am thinking of purchasing the F12 & wondering if anyone can share your experience & thoughts
with regards to overall sound quality.

Mant thank

Superb DAC ESS9038PRO tube output from HQ Audio, with digital inputs and USB (Amamenro USB interface, one of the best)
Built with audiophile quality parts (Mundorf Supreme Silver/Oil/Gold output couplig caps, a 550$ upgrade just in itself, etc), multiples power supplies for best signal insulation and noise reduction. Choice of 5 digital filters for optimized sound
From the Front panel Inputs selection, Volume control and Mute, as well from remote control included
Front panel displays all parameters and Volume setting
Supports 44, 88, 96, 192, 352, 384KHz PCM et DSD, Low jitter clock (jitter of 0.5psec)
Inputs SPDIF RCA, AES/EBU, optical Toslink and USB (Amanero Interface, one of the best)
This DAC was lightly used, so the 3 tubes are still as new... 100% perfectly working condition.

You can add a Raspberry Pi3 controller to use it as a streamer. I never installed it but Quango is mentionning it into his user manual. The chassis is already pre-drilled for it.
My built also includes the Raspberry low noise optional power supply already installled.

This is a design by HQ Audio: https://quanghao.com/. Well known audiophile builder in Asia.
Full documentation available including the user manual.

Asking 550$, (can lower the price to 350$ if I keep the Mundorf Supreme Silver/Oil/Gold caps and installed the original Solen-MKP caps)

Shipping at the buyer expense or delivery in Person in the Montreal Area.

For details send me an email

Thanks for looking
SB

The chipset in production almost 2 years - https://www.qualcomm.com/content/da...pdragon-W5+W5-Gen1-platform-product-brief.pdf, , but Qualcomm limited documentation even for registered users on their portal.
Looking for any docs for SW5100-0 + LTE RF front end - possibly (?) someone has access.
I have all documentation related QCC5100 co-processor and WIFI/BT front end, but almost nothing about main CPU.
Appreciated for any help!

Hi, I need help in connect Amanero to iBasso DC03. I have some iBasso DC03 (two mono CS43131) with brocken SA9302L and chinas Amanero. So i want repair iBasso and connect it to Amanero transport. Problem that i have now is that SA9302L footprint on board do not have DBCLK contact. But in iBasso DC03 specification written that it support DSD.

I want to save DSD support, but i dont understand how it work without DBCLK contact with SA9302L

Here photo of board footprint:

Hi, I'm Pietro and I've always been passionate about hifi music and lately also home cinema. I find the forum interesting and lots of passionate people.

I have two Arcam Alpha 10 Amps.


The FISRST ONE:
It works fine on headphones on both channels but I get no audio on Right Channel on both speakers SP1 and Sp2.

Where shall I start looking for faults please?
The MOFSETs seem fine.

The SECOND ONE:

The amp very briefly powers up and displays for less than a second and then it shuts down.
It had two MOFETS shot ( zero reststance ) on SP1.
SP2 MOFSETs are ok

I removed the two faulty MOFSETs from SP1 and powered it up, it stayed on for 5-6 seconds but I culd start see smoke from one of the resistor.
If I replace the MOFSETs could it fix the issue?

I'm wondering if you remove the MOFSETs from one set of speakers shouldn't really the amp stay on but not burning anything?
( Service Manual Attached )

Thanks

I am modeling enclosure for SICA 5,5 coax. Effective diameter of speaker membrane is ~100mm, overall basket size is ~148mm. Box will be printed with 3d printer, so almost any reasonable shape goes...
Currently thinking about drop shaped box. Modeling directions of the front baffle for it:

• A: More narrow, ~170mm diameter, which is (IMO) reasonable width to get some rounding and still be pretty minimal
• B: Wider, ~220mm diameter
• C: Unreasonably wide, ~280mm - a bit of Snell Type A philosophy

Of course, there is some space to make it even more narrow - ~160mm wide or on the opposite - even wider

Inside volume of the box will be the same in all cases.

Here are the approximate drafts in CAD and diffraction simulation in VituixCAD. All I can see is the difference in the frequency of the baffle step.
A - narrow


B - wider


C - very wide



I cannot see anything wrong in any of these choices, as it is a coax driver with recommended crossover frequency between 2,6 to 3,2kHz and the waveguide for the tweeter is already what is and I cannot build BSC into crossover as it is already bigger than I need.

Probably will 3D print 1 mockup of final box, but not all three - too expensive and time consuming.
Which baffle direction would you suggest?

Could anyone help with the equation that can convert from frequency response curve to phase reponse?
(Something that is done when you measure your speaker response?)
Thanks.

As one of the last parts of my project, which are crossovers, I noticed that there are several types of them.
And I don't know if this is like musical instruments where their difference is so tiny that the best sound they make is when they hit the bottom of a trash can.
I noticed that there are several such as Metallic Film (MKS/MKP), Polyester (PET/MKT), Electrolytics (Aluminum and Tantalum), Ceramics and the most famous in the field, Polypropylene (PP) / Metalized Polypropylene (MKT) Capacitors.
From the various videos of amateur people (like me) that I see on YouTube who try to build a good quality hifi system, they use electrolytic capacitors, but when I was researching I saw that some people say that they are not that good.
And when I try to find the same value of 100uf, 56uf, 10 or even 12uf they are infinitely more difficult to find than electrolytics.
So what's the verdict? Which one should I use in my first hifi project?
What is your opinion about it?

Howdy, does anyone know what kind of core TAMURA F -913 A are? Or any info. These are cheapest Tamura SE output transformers.

I figured rather than driving myself crazy(er) that I would just ask on this one. I'm looking for a small subwoofer driver that I can use in a 3 way design. Would like to get a pair to run it in isobar. I would be matching them with a RAAL 70-20 and a purifi 6.5" driver (still haven't decided which). I'm already aware of a few that may fit the bill from dayton, kartesian, and misco, but I figure I would just ask around to see if there's anything I missed. Any help is appreciated 🙂

8 Hypex UCD modules (50 watts per channel). Rotel did a good job with this amp. The chassis is well ventilated, and there are 2 fans on the back in case it does get too hot. I've never heard them. The chassis is very robust.

Has optional digital inputs, and 12V triggers

$600 plus shipping from NV OBO

Hi there.. any syggestions for box size of a 2 way bookshelf speaker .. I have allready the cross over.. its a kit.. but they dont suggest a "box size" - I have found software to calculate for a SUB that I also want, but I need to find out how big/small that box for the tweeter and midtone has to be... ( I am thinking about cutting from 80Hz and down and let the SUB handle the rest "bass") ....

I am assembling an ICE Power 1000ASP power amp (with a 1000A "hanger" board for a second channel) to drive a new pair of subwoofers. I just realized the amps only have balanced inputs, with +/-12.8 volts specified as the input voltage limits. My problem is that I want to drive this amp with my miniDSP Open DRC-DA8, which has only single-ended outputs with a 2 VRMS range. I'm assuming I'll sacrifice a lot of dynamic range, and risk high noise levels, unless I convert the DRC-DA8 to a balanced signal before sending it into the 1000ASP/A.

1. Is my assumption correct?
2. If correct, what are the options for making the conversion?

I've seen "active DI boxes" that seem designed for a similar purpose. If they are appropriate, are there characteristics to seek out or avoid? Or, would a pair of DRV134PA line driver chips inside the ICE Power 1000ASP enclosure be sufficient? The ICE power supply provides +/-12 VDC outputs to drive accessories, so the power is already there. I have no experience with those chips but implementation looks straightforward.

Thank you in advance.
Few

Hi all, I'm after some help from the experts if i may. Ebay special, quad 99 power amp, the amp will not come out of standby. Im going to use as a stand alone amp so i have the selector on the "Input" but the red light stays a constant red.

I have attached some photos of the board, which it appears to me, has had a mod of some sorts. can anyone confirm what the mod is for? and by chance could this be to bypass the selector switch???

Any thoughts gratefully received. Thanks.!

PS thanks for the group!

current equipment: 2x 405's dada mods and re cap, 2 x 306 dada recap 1 x useless 99 😁

Maybe it's just me, but when I look at a particular posts "attached images", I get attached images from other, different posts as well.

Not that it bugs me so much, but, thought worth mentioning as a functionality anomaly I'm seeing; I know the "Hornresp" post doesnt have 96 image attachments...

Here's a ported 2-way designed in the US and assembled in the US from mostly Chinese parts. Sold direct to consumer, the MSRP is $299 the pair. I'd say that they are cutting their profits pretty thin.

I have written a very "Long and Winding Road" review, because my readers like "Long-Form 'Think Pieces'."

At the end of the day, whether the compromises embodied in this speaker will work for you I think can only be resolved by an in-home trial. Fortunately, the maker offers an MBG.

But another way to look at it is, for $299 you get a nice-looking pair of cabinets, and you can either redesign or upgrade the crossover, or throw out all the innards (or sell them) and find nicer drivers to fit the cutouts!

https://trackingangle.com/equipment/vera-fi-audio-llc-vanguard-scout

amb,

john

Hey, ya'll! Been building speakers for 5 years now, trying to create as many different kinds as possible.
Right now looking at making an open baffle speaker based on the walnut dipoles. Also planning my build for next year where I would want to try my hand at making an electrostatic speaker.
Looking forward to interacting with you all!

Finished building an Amp Camp Amp last week, now I'm tackling the B1 pre-amp.

Considering replacing electrolytics on input with 10uf ceramics. What do you think of that, improvement in sound, further degradation from electrolytic? Suspect lytics are drifting as each other one in this preamp was. Here is a snip from the schematic.

Hello I really enjoy audio in general.
I studied electronics and repaired audio equipment a long time ago.
Now I have some amps, turntables, tape players, equalizers which I enjoy very much.
I like to learn and from time to time I find audio equipment that needs repair and I try to repair it.

For sale a working preamp and it even works with universal remote control.With remote you can power on and of,choose input and of clurse volume up and down.But the remote is not included in this sell.I have using universal philips remote.This was a amp first,now the output amp modules are defective,I have take this out and made a nice sounding preamp out of this.The preamp section is the same like in Aaron no1. amplifier from Grrmany and have cost years back about 3500 eu.Look online.I have put some new caps on the modules and on the pcb some new nichicon psu caps and some new resistors.This preamp using one pair of single opamp per(channel) module.So you can try diferent opamps in this modules and tweek the sound colour.The pre will come with opa27 opamps!The preamp will be well packed and shipped.The price is 150 Eu including shipping inside EU!!! or best offer.I dont need this pre so if someone will play with this just make me some offer.The pre have 7 kg of weight.

Hello DIY Audio Community!
Mike, 52 y.o, live in Moscow.
I became interested in electronics and sound reproduction during my school years, I love when music plays loud and clear!
I have started with AM radios, then made some mods to cassette desks - the most interesting and successful was a dynamic bias like Dolby HX pro.
Despite the fact that I graduated from university with degree in electronics engineering for a living I work in the field of data networks, telecommunications and IT.
Throug the years I did repairs (amplifiers, SMPSs etc) but have no finished projects, what a shame)
Analog electronics remains my beloved hobby, as my kids have grown up now I have more time for my passion, even received a ham radio license!
For a long time was a quiet reader here, hope I can bring some value to the Comminity - there are many interesting topics.
Cheers!

Hello

I had to do a cable for I2S with RJ45 from my interface to my Aqua La Voce S3 dac
The signals from my interface are Data-BCK-WCK-MLCK. The Audio gd interface has a hDMI out so it is in balanced mode. I took the signal inside before the HDMI chip which takes unbalanced signal to HDMI balanced. There was 42 ohms in signal paths (Data-BCK-WCK-MLCK) that goes to HDMI chip. Il took them out to unload because I didn't want to feed HDMI chip. It was perhaps un necessary but... As it is, it doesn't work with the Dac.
Can I check with a scope if there is signal coming out of Data-BCK-WCK-MLCK ? MLCK is not used as I don't need it with R2R dac. The connections were checked many times and they are correct.
HL-MLCK- Dale are not used on RJ45.

Hi everyone, I live in Venice, Italy. I am an electronic engineer and I teach at the technical high school in Venice. I have been designing and manufacturing audio equipment such as power amplifiers, preamplifiers and speakers for over 30 years. I am an expert in audio measurements and I want to share my experience with you.

I've been trying to design a Class-AB power amplifier using two Sziklai Pairs in the output stage, using BD140+TIP35 (the PNP pair) and BD139+TIP36 (the NPN pair).

The design is in the image I attached.

It has some a considerable amount of distortion in the whole spectrum, plus clipping when I try to amplify a larger bass signal, a reasonably treble and hard clipping much before the clipping should actually occur.

And the thing is that I think I don't know what I'm doing anymore. In the beginning, I tested the design in MultiSIM and apparently it worked, but in reality it had a ridiculously large RF instability that caused the current drawn by U2 (I used a multimeter in the same place of the one in the design) to increase by 10 fold (from 20 to 200 mA) when I simply connected two wires to the output, the wires being connected to nothing, just because of their capacitance. And when it did this there was a 100 R resistance limiting the total current in my source itself, could be much larger without it (I only removed it after making the circuit stable).

It took me long to figure out how to fix this, then I found this design that used a capacitor from the output to the stage before the output stage (C5).
Connecting a capacitor similarly (also C5 in mine), the instability went away, but I'm not sure if it makes sense in my configuration, even why here I had to keep its value small, otherwise there was much more distortion. With 100 uF there was distortion at low volumes even, with 1 uF it worked a lot better.

But still, no matter how finely I adjust the bias in the rubber diode, there's still noticeable harmonic and non-harmonic distortion, the worst being a hard clipping at larger volumes, in bass in particular.

But it's happening really before it should.

Q7 and Q8 transistors in my diagram should be limiters, activated only when the voltage drop on the 0.15 R resistances were around 1.4 V or so, so a current of 9A or more, which I doubt I'm hitting before this clipping I'm hearing.

Should I test removing them just for a test, or perhaps this is coming from another source?

Any way, I seem to never get a really good quality audio no matter how much I try adjusting the biasing rubber diode, the clipping isn't the only issue.

So I'm asking to check what flaws I have in my circuit that I should address.

Greetings! I am a Systems Engineer in California, USA.
I am currently evaluating the imx8mplus from NXP looking to build the AVB networking for Audio. Happy to meet you in this forum.

Hi,
As per title I've this assembled boards for sale. Never installed.

DCT03 DC FILTER FOR TOROIDAL TRANSFORMERS​

Asking 200 eur
Thanks

Reading through some people's builds and recomendations I came across people adding a SIGNIFICANT amount of weight into their enclosures. On the order of 50-100 lbs.
I saw the saying "double the MMS" multiple times like its some sort of rule of thumb.
I have some plate steel sitting around doing nothing. I could add it to the bottom of the cabinet but does that actually make a difference?

-Sold- Those are from the first batch at the diy audio store. I have just take them out of the chassis and were playing perfectly. Assembled with good quality parts. Amp boards only, no psu boards. 50us shipped to Canada and 55us shipped to USA

For sale a pair of completed Mofo boards plus a pair of Hammond 193V chokes for big mofo(24V supply and 2.5A bias) and Nichicon Super Through 15000uf 50V pair output caps.So all parts that you need by building a verry good mofo amp.All parts verry good condition,used but truly good condition,only the caps have some minor signs of use.Price for all together is 200 euro plus shipping inside EU.The shipping cost will not be low becouse the two chokes have over 10kg of weight.So plese ask first for shipping price.

Not sure if it's the right forum. I've never dealt with lightning damage, but received a call from a buddy that there was a lightning hit near his house resulting in dead AC unit and some of his precious electronics. His expensive Mcintosh SACD and fairly recent tube amp appear to be dead. Mcintosh tube tuner connected to the same power strip survived , probably because it does not have a ground wire reference. According to him the stuff was turned off but I'm not sure it was turned off by the mains switch or simply on standby.
Maybe he should call his insurance agent first before we pop the hood off the gear? Not sure how those cases are handled.

Typically for Class A amp builds DIYers are using aluminum extruded heat sinks for which the base and the fins are part of a single block of metal.

What if a heatsink is built up using a 6mm -8mm base plate with smaller heat sinks with fins bolted on? Would there be a lot of efficiency loss and concerns on thermal performance?

I have attached pics of a flat bar/ rectangular plate and smaller sized heat-sinks for reference. The heat sinks are 60 mm tall and 179 mm long - if we stack two and attach it to flat rectangular piece, then we can get a heat sink which 120 mm tall and 179 mm long. The pics are for reference purposes only. Ideally the heat-sinks can have a thinner base (4mm - 6mm)to keep cost (and weight) down.

I have just gone on the Lowther site:

https://www.lowtherloudspeakers.com/

which is interesting in a couple of ways. They have gone a bit upmarket. The factory made cabinets look much better made, with prices to match. £7000 - £18000 (+drivers!) that I looked at. The response curves look fairly realistic, (like the HF drop off at 9-10k) and confirm, that, without front horn loading, the PM6a 8ohm silver voice coil gives the flattest response.

However the most interesting thing I saw was that with the factory made speakers like the TP2 they recommend adding the “Lowther Super Tweerer”. A definite break with history.

I've been away from this site for a while but in searching for Amber 70 threads I see there are a number of questions, however old.

I was a consulting design engineer hired by Keith Rosenfeld who owned the company. We were going to bring out a new line or products, including a super good preamp, along with an upgrade to the Amber 70 and a new product the Amber 200. Unfortunately, our venture group went bankrupt before we had the new product line out and that was the end of the company.

After the downfall, Keith shipped all the excess parts inventory to me, which I still have. If anyone needs schematics, notes, parts, drop me a line, I can send you a PDF at no charge. BTW, the LM391-90 chip is still available although the -100 is not. For the Amber 50 or 70, you can substitute it the -90 without a problem.

If you need something, drop me a private note. I don't repair Amber stuff anymore so if you need something, let me know, and I can ship it to you - along with any helpful hints and answer any questions you may have.

Hello,
I recently purchased some rare DLK ULMs (electrostats made by Janszen). I believe these were the same units used on the Z-II CF which I owned and sounded wonderful. I contacted Janszen to see if they had any information on the unit and unfortunately, they did not. He did tell me they should play down to around 800hz and have a 2nd order (single L/C) filter ahead of the signal step-up transformer that rolls off below 800 Hz. The capacitor is a 4.7uf but I am unsure of the inductor value.

I have wanted to use the Dayton RS225s for a while. I'm tempted to build two enclosures with two RS225s in each and the electrostats sitting on top, I really believe that has the potential to sound amazing.

•Would the RS225 or RS225P be better?
•For load, would getting (2) 8 ohm and wiring in parallel, along with the Janszen in parallel be the way to go? Or, (2) 4 ohm in series with the Janszen in parallel?
•I do not have much experience designing crossovers. I would think a simple 1st or 2nd order would work. My concern is all the variables...load resistance, desired Q, flattening the x-over hump where the two drivers meet, etc, all come into play and I am unsure how to start.

Here are the guts of 2 stereo Calaf amplifiers.

All of them had exact same problem, bias board failure. Otherwise these are working boards.
You don't really need the over complex bias boards, instead you can place a normal adjustable bias circuit with a few components.

You get:
-3 complete boards, one gutted. 2 boards have also the copper heat spreaders in place.
-3 bias boards, which can be used for reverse engineering the circuit. Otherwise the schematics are available in the internet, except the bias board schematics.
-Power transformer for 2 channels
-1 power supply board for 2 channels
-pre cut insulator pads for 2 channels

Output boards have genuine Toshiba 2SC5200/2SA1943 matched pairs. All together 21 matched pairs. Also you will get 24 PC's 10000uF/80V Nover capacitors.

I'm asking 200€ for the whole pile or reasonable offer. Can be shipped almost anywhere.

Hello, me again...
There are EMT-SME adapters around, allowing the use of a headshell on the other tonearm (mounting-system)... but, don't these spoil the geometry, by prolonging the arms length?
Asking because, again, I'm tempted to get me a EMT-headshell, for the cool look and the functionality are... "groovy" B)

I'm Guillaume, an amateur speaker builder since 2014. I would be pleased to introduce some of my projects to know if I made them right. I would like to Improve the knowledge behind shapes, volume and all parameters that make a speaker well designed.

Hello ,

I recently bought a pair of ElectrVoice ZLX12P.One is faulty, with a burnt 12" woofer.
Can you please help me find a replacement woofer , that I can buy in Romania?

Thank you ,

Hey guys,

Is there anyone with some decent plans for the Invader-Bins?

I cant find any in the original Speakerplans-Thread from nineleaves (all deleted).

All I found was this plan on 'Plans Systemes'.

But I think its one of the older Plans from nineleaves and also is reworked from Plans Systems (which im not sure if they are correct).
When you read through the Speakerplans-Thread you can read of a lot of fixed and renewed plans from nineleaves that he postet there.

I would love to have the original 'final' plans from nineleaves. Or maby a modded plan from someone who build and succeded? Maby also the Cut-Sheets?

Original Thread : https://forum.speakerplans.com/my-18-horn-invader-bin_topic11659_page1.html
Plans Systemes : https://planssystemes.notion.site/Invader-Bin-9eb124e9ffce423ead38b62d557e2ca3

With all the best,
C.

looking for knowledge about an old Masterwork tube receiver I inherited from my dad. I believe it is a rebranded Pilot

Hi.
I've already built a bench power supply. Built is a stretch. Cobbled.
It gives me 24V 3A with current limiting single rail power. I believe it uses a crowbar to limit current.
I built the Volt and Ammeter using the Intersil chips in Led format. (Also built them in LCD). It has a temp regulated fan on the heat sink.
I built it so long ago. I can post pics if people have the stomach for electric gore.No Printed PCBs here...just hackery !
I'm sure it meets no standards....at all....except electric isolation. I think...hasn't caught fire , even under alot of stress.

Now ,I'd like to build a dual rail power supply. Using the Intersil ICs (Something about building your own meters).

The killer is the transformer. Shipping is quite prohibitive for a decent toridal transformer that can deliver say 1000w at Max 48v.
Though I suspect I can use 2 switch mode supplies in series an use the bond as Common and I'll get my +Vc/0/-Vcc..correct?

But any noise from the switch mode would insert itself into my unit ..correct?

Any recommendations on tried schematics?..the working ones. 😊.

It's been on my list for a while and I'd like too build 3 units of my own. Not because its cheaper, it isnt , but because it's fun.
The 3rd unit ,I will play once again with an Arduino to control it. But bumping this unit up to +/- 60v 10A. .
A finger in the right direction ( the index preferably) would be much appreciated.

Hello all, I'm based in Truro, UK. I'm looking forward to working with you all to design an awesome open source smart speaker enclosure

I'm a new member dedicated to electrical engineering

Hi, I admit - I came here by Google because a member is selling NOS transistors.
I am an electronics engineer from Hamburg and mainly work on industrial electronics and music studio gear.

So my relation to audio is actually not so diy, although I built amplifiers in the past for my own use. But this has become a victim of lack of spare time unfortunately.

I hope to find some interesting exchange on audio circuit related topics here and, yes, maybe NOS components that become harder to find every day - or offer them if I see someone needs what I have.

regards
Stefan

I'm possibly a returning member. It has been a good number of years (around 15) and I'm going over an old amp design from years ago. I can't make head or tail of it now !!

Hi i have a sony az77dbt hifi system in which used a class d amplifier and AK5358 as ADC board which is damaged can i replace with AK5720 SUGGESTION PLEASE attaching the pin layout

Hi I'm daytonet. I've been lurking on this forum for a long time but recently decided to join as a member. I'm excited to discuss lots of things regarding audio technology with you guys 🙂

Are budget DACs, sub $200, worth it? DIY would be way outside my abilities.

I have never heard or even seen, in person, a stand-alone DAC.

I have a question for you guys.

I want to use 16 AWG internal hook up between passive crossover and drive units for my speaker project.

However, shouldn't I use 16 AWG internal hook up between binding posts and input of passive crossover?

Some say thicker is better for that position. Any comments 🙏

Hi,
I have buy in France, a DAC WADIA Digimaster X64.4, I think Year 1990. Do you know the price $ in 1990. Best regards.

​

I've asked the question on the multi-way forum, but will post here too. I would be keen to know what FR driver you would suggest for this smallish stand-mounted triangular prism speaker. As I burn in the Alpair 6.2s on my home streamer, I'm becoming increasingly a member of the FR fan club. Speaker dimensions and volume will follow the driver, but volume most likely in the 4-10 litre range. Keen to seek a similar sound to my B&W 607s3s with forward mids and sparkly highs while retaining good bass performance. Can be sealed, ported or even TL (if a TL in a triangle exists!).

Hi everyone, I made a pair of this speakers a while ago. I always though that's a transmission line or a "quarterwave" design. But is it really ?
They are made around the Tang band W8-2145 driver, blanda bowl (the large one 28cm) and a PVC pipe (about 210cm long and 6.3cm diameter). All of this sealed in a concrete base which incorporates the connectors. Sorry, I don't have graphs and mesures, but they sound good-ish to my ears.
First I designed this speaker with the 1/4 wavelenght type of enclosure, but now I'm wondering if it is a transmission line or a very long ported design.
Thank you by advance for your reply and feedback.

I want to start a thread about this kit build process because after some tinkering and adjusting this amplifier sounds much better than stock, in my opinion, and will be far more reliable. So first thing I want to say is that I built this kit exactly to the guide/schematic and then started to make changes. First thing I noticed was how hot the output tubes were running. The schematic suggests running a 300b with 482 volts at the plate with 73ma plate current. In my opinion this will fry any standard 300b pretty quickly. So the first mod I performed was to bring the plate voltage down to 400. Mine was actually running at 495 and 75ma. So to get the voltage down you will need to use the purple b+ tap, not the red, and use a 5u4gb rectifier tube. This will get you to 400v and 60ma which is a more typical operating point for 300b. This is just one of the mods I have done and there are several more to discuss but I’m interested to hear about others experience with this kit before I move on to the other changes. I have attached photos of what my build looks like at this point. So please chime in if you have this kit. Cheers Thomas

Hi Guys - More 3e Audio stuff that I bought and have done nothing with. Just want to move it on to someone who will make the project and appreciate it.

This is my first time and I hope it is OK.
Starting with:

AMP Balanced/unbalanced AUD85.00
PSU AUD75.00

Plus postage to wherever you are.

PayPal (family and friends.

Thanks

Dan

The NXL550 R1.0 amplifier module is a high performance, hi end amplifier module capable of over 500 watts into 4 Ohms and is 2 Ohm and 1 Ohm stable for short periods (60 sec).
Directly driven from an OPA462 High Voltage Op Amp.
It features the option of adding separate regulated input/driver stage supplies for even high performance.

The current power measurements were done on a +-70vdc linear power supply, higher power outputs can be achieved with voltage supplies as high as +-75 volts and with other versions that are capable of handling DC power supplies as high as +-90 volts DC.

The main PCB has an over temperature and over current LED status Flag which also serves as an output clipping indicator.

Specifications:

8 Ohms: 245W per channel, powered from +-70vdc supply rails

4 Ohms: 425W per channel powered from +-70vdc supply rails

8 Ohms: 300W per channel, powered from +-80vdc supply rails

4 Ohms: 545W per channel powered from +-80vdc supply rails

Frequency Response: 20Hz-20Khz, -0.1db, 3Hz-210KHz, -3dB Input filter limited.

THD: 0.002%, 1khz, @200W into 8 ohms: 0.01% 10khz @200 Watts into 8 Ohms

IMD: 0.002%, @200W RMS into 8 ohms

SNR: -105dB, Unweighted, referenced to full output; -112.6dB A-Weighted

Damping Factor: 800 into 8 ohms, 100Hz

Gain: 22 (27dB) other gain options are available upon request?

Input Impedance: 22k Ohms Unbalanced:

Inputs: RCA Phono

Recommended Linear Voltage Supply +-70 Volts DC
For higher power output +-75vdc can be used.
PSU Power Transformer secondary windings 50vac (800VA)
Printed Circuit Board Dimensions 105mm x 72mm
Small form factor PCB



Captured Images Showing the following.

1Khz Sine Wave driving 8 Ohm load
1khz Square Wave response driving 8 Ohm load
10khz Clipping response driving 8 Ohm load
10khz Square Wave response driving 8 Ohm load

Hi,

I'm looking to buy 2-4 genuine IXYS IXTQ69N30P.

Out of stock everywhere for now

Thanks
Do

Hi, I have a few questions on a simple matter . Most of the amps I've built never used pots for volume control, I used the signal source's volume control ( digital ) for that .
Now using the classic volume control with a pot like this : would this affect the quality of the signal ? or , change the input impedance based on the pot's location ?. Using a buffer before the pot would help ?.

What about this , would this be a better approach ? besides the output being inverted and not being able to have " zero volume ". would this affect the input impedance as well when pot is turned ?.



What is the best approach for this ? Best way to use potentiometer for volume control ?. ( besides using digital volume control ic's )
- Bruno.

Hi-

Here is my SME 3009 s2i phono din socket adapter. It may work with others, but that is the only model I have. It is made to fit this connector https://zavfinousa.com/collections/hi-fi-connectors/products/rb-250-din-socket-replacement. As well as the shield from the RCA connector.