I had a working ra-1412 that ended up blowing three output transistors. I have gone over and over it and I feel like I am running in circles. Transistors, emitter resistors, and everything I test seems fine. Then I discovered if I unhook e1 wire from the right main amp board, no short. E1 is connected to the phono board. Should I be looking at the phono board?

So I'm building an active speaker. The preamp is going to be custom and discrete (op amps, caps, etc.). The power section however I am torn on. From a design perspective, to get the best performance in things like SNR, THD+N, etc., which is the better option: full discrete, chip amp, or just get an evaluation board (ex: https://www.ti.com/tool/TPA3255EVM ) ?

Greetings!

I would like to turn on my Akai AM-95 after it has been sitting idle for more than a year and do the maintenance it requires, i.e. replace a defective potentiometer that proved time-consuming to source.

As far as I understand, applying full mains voltage might be a bit too much for some of the electrolytic capacitors... I don't have a variac, but have several incandescent bulbs of different wattage, starting with 15W.

Would the dim bulb be the way to go? Any cons to this approach?

Thanks 🙂

I just noticed that Antek is selling balanced isolation transformers with filtering and Faraday shield for very reasonable $. BP-400 at $155, BP-600 at $175, and BP1000 at $195. I think they do not sell the balanced transformers separately, but there seems to be enough space to allow some modification. like adding MOVs/GDTs. Unclear if the outlets can be replaced. Any thoughts?

Hello,

------------------------------------------------------ORDER WAS UNSUCCESSFUL-------------------------------------------------------------------


This is the current situation. I apologize if this caused any inconvenience for you. I will update as soon as possible
https://www.diyaudio.com/community/...st-tht-i2s-input-nos-r-2r.354078/post-7248352



I have 14 AD1862N on order from DigiKey. There will be 12 up for sale, 6 pairs. I should have them in about a week. Limit is 2 Pairs per person.


Price per pair – $52

+Plus+

Shipping inside USA – $14

OR

Shipping outside USA – $22



If you are interested please send me a PM including your

1. Paypall Name

2. Shipping address

Payment requests will be sent once I receive the package from DigiKey. Packages will be insured. Once your package is shipped I'll send you a PM. Shipping from NorthWest Arkansas. I will reply to PM's after 6 on weekdays.



Thanks 😊

North

Hello,
I'm new to this forum and was looking for a bit of advise re the driver in the attached photos.
I was gifted a homemade speaker unit from a musician friend who's uncle had built this himself some years ago.I'm assuming the model number is Western 3013 - C or 3015 - C but not sure as I can't seem to find any information on such models. Does anyone have any idea as to the details and what the actual model number is?

Many thanks

I am working on a project making the NOS dac based on the TDA1387 x8 parallel chips.I had it as a dac hat on a Pi3 and just recently because I like it that much I have installed it all in a sharp case and sperated the boards instead stacking etc.My next step was I wanted to get a better clcock as its using the Pi master clock now. I own a digi2 pro, I cant find any reclocker boards on used market then dawned on me the DIGI2 pro has dual clocks high precision. I want to know if I can feed the clocks from the DIGI2 pro GPIO pins to the GPIO pins the protodac uses for clocks. THe DIgi2 has a header allowing it to be used with other hats including their DSP board. I cant seem to find a solid answer. From Hifiberry site regarding pin out of DIGI2 pro

HiFiBerry Digi+ Pro, Digi2 Pro​

GPIO2-3 (pins 3 and 5) are used by our products for configuration. If you are experienced with I2C, you might add other slave devices. If you a a novice, we don’t recommend this at all.
GPIOs 18-21 (pins 12, 35, 38 and 40) are used for the sound interface. You can’t use them for any other purpose.

GPIOs 5 and 6 are used for the clock circuit and cannot be used for anything else.


ANy help appreciated.

Finally, an article..
https://www.nature.com/articles/d41586-023-03043-0

Maybe 8 years ago, the lead scientist called me to ask how much it would cost to make a new antimatter trap magnet. He wanted to know if it scaled with length, as the new one needed was a lot longer. I said, not sure, it might be less than linear, as straight lengths were a bit easier than the corners.

He also said... oh, by the way, it will be mounted vertically... to which I said, "oh, you're testing gravity". Suddenly, dead silence on the phone... It was a secret.
(note. The actual magnet had significantly more coils, with accuracies below .001 inch, it was a bear to make..)

End result.. we built the magnet and didn't know what was going on for roughly 3 to 5 years..

Published, cool results.

The techs I work with are the best in the world.. This could never happen without the skills of the two guys who did the work. They are awesome, I am in awe.. Actually, my words to them as I shook their hands were.... you are "effin" great. (nanny software prevents actual words..)

John

ps. It is unfortunate that money doesn't accompany the accolades, as the techs certainly deserve it.

Sure would like to see an update for the QA403 tutorial

https://drive.google.com/file/d/1VR7he94XshEV8BaX275OxtANXiDuglVo/view?usp=sharing

Hi guys,

This time I would like to ask for a service manual / adjustment instructions for my Accuphase DP-500 I am using since 2009; the reason is that sometimes - especially with long CD`s - the player is loosing the track at the end of the CD. I have already a new KSM-213CCM, which I plan to exchange against the old one. I have a Tektronix TDS digital scope and some other measurement equipment for the maybe necessary adjustments.
Thanks in advance for every hint solving this!

best regards
Dieter

Hi, component prices have skyrocketed, but many retailers are selling out old stocks with 20-50% discount. Please link such websites or lists here!

Loudspeaker drivers eg. Satori, Purifi, SBA... https://www.speakerbuddies.eu/en/specials.php

Hi everyone,

I was making a design for a two ways crossover on vituixcad. For the tweeter I opted for the Peerless XT25TG30-04, 4 ohm nominal impedance, and for the woofer the SDS-P830657, 8 ohm nominal impedance.

In the picture of the crossover scheme to me impedance looked fine, reaching a minimum of 4.0 Ohms at about 2100 hz frequency.
Minor corrections aside, I could not find any way to fix the 3-4 db peak at 1000-1200 hz, to make the whole responce almost flat.
I'm open to suggestions to fix this issues or other things I could not notice.
Thanks in advance

(pics of the crossover and graphs together with frd and zma files are attached)

This thread is for help and comments as we (alanhuth and flohmann) make an Aleph J build guide aimed at noobs like us.

UPDATE: six months later, and it's done! Thanks to all on this thread for the help along the way!
DIY Aleph J: A Build Guide

The idea is something more detailed than 6L6's excellent illustrated build guide, with more context for beginners. For more on the idea, see alanhuth's original "modest proposal" thread, which wished this effort into existence.

This thread was where we showed our progress at putting together our noobs guide, ask for help, and welcome comments about it.

This noobs' guide will be for building a plain-vanilla, single power supply, US-voltage Aleph J, built from the DiYStore boards, 4U Deluxe chassis, and DiYStore transistors. Since we're in the US, we focused on US parts sources for the rest of the BOM (like Antec for transformers and Mouser for parts).

The guide lives on Blogger (we're hoping to save noobs from having to work through hundreds of thread posts, after all):
https://diyalephj.blogspot.com/.

Here are direct links to the posts:

• Introduction: What is this and who is it for?
• Introduction: What makes an Aleph an Aleph?
• Introduction: Tools You Will Need
• Parts: Stuff to Get from the DIYAudioStore
• Parts: Transformers
• Parts: The Rest of the BOM
• Building: Good Build Habits
• Building: Power Supply Board
• Building: Amp Boards
• Building: Amp Boards on Heat Sinks
• Building: Assembling and Testing the Power Supply
• Building: Amp Board Power Up and Test
• Building: Chassis Assembly and Final Adjustments

I'm just in the middle of this project, so this is a provisional schematic. I've done the output stage so far, which is as the schematic.

Input stage will be 6V6 in triode or 6AH4, whichever sounds better. Other tubes are possible, e.g. EL33 in triode. Needs a mu of around 8 or over. I originally planned a 2P29L or 112A input but ran out of room in the chassis.

The EL12n is an 18W dissipation tube with a mu of 18 in triode. The bias is low at around 10V so I used separate cathode resistors as suggested in the data. I don't know if 150R needs a cathode bypass but I've put in a DC Link one.

I was thinking 4V bias on the input tube to use a 220R resistor and avoid a bypass cap. This might be up for discussion.

Any suggestions and improvements very welcome.

Dear fellow DIYers!
I have built an ACA into an old Mac G5 (cheap aluminium) and an ACP+ with it. Now I borrowed a BA3 with "real power supply" and find it such a great improvement that I was wondering how I could build a power supply with toroidal transformer myself (for ACP+). Can somebody help me out with a BOM or guide or so? I'm quite new to building. Also I was wondering whether it might have to do more with the BA3 Vs. ACP+ or rather power supply? Thanks in advance for all your help!
Kind regards,
Johannes

Hi.I bought a LLC SMPS from China.It is here HIFI Audio Soft Switching Power Supply Board For Power Amplifier +-36V +-48V 500W | eBay

I thought the price is good but i am a bit disappointed.It did not come with Rubycon caps at input and also output.It also seems it is made a bit low quality.Poor soldering I have a limited information about SMPSs and also LLC.As i heard LLC is very sensitive about L and C values and resonant frequency. As a capacitor seller i have much more quality than the caps at input and output caps( 120uF 450v and 2200uf 50v) Especially 2200uf 50v seems very low quality. Can i change them without problem?Is there any need of adjustmens ? (altough it seems there is no adjustment trimmer or sth like that) I am using it with iraudamp7s in bridged mode for my 6ohm subwoofer.(SB34NRX75-6) SMPS Voltage is +-48v Plays music and cinema good.Good dynamics.But i want to improve Thank you in advance.

Pre-millennium, every electronic device, sports car, & electric shaver had 2000 in the product name. I guess the marketing department thought it sounded cool. Realistic (Tandy) when nuts - they named everything a 2000.
As a result I can find nothing on this tuner / amp.
The System 2000: SA/ST-2000L
Anybody?

I will start a small group buy for

a) FC-100 Amp Boards
b) Stackable active rectifiier LT3062 front end PSU
c) Active rectifier for screw contact caps (e.g. 22000µF/63V RM22.2)

All boards with 2oz copper.
a) and c) 2mm thickness. b) 1.6mm thickness.
Green soldermask and white silkscreen.

The boards never tested in reality but the FC-100 is a bullet proof design.

The FC-100 is based on Roender´s design.

https://www.diyaudio.com/community/threads/rmi-fc100-a-single-stage-audio-power-amplifier.111756/
These PCB design is based on Rudi’s design with some little improvements.
All Pads are bigger for better soldering. The traces are bigger.
More space for the dc coupling cap at the input (I will use a clarity esa).
A small bridge for feedback instead a long wire (J1)

If someone is interested, I can provide all layers as pdf to double ckeck them with the schematics.


I will order to the end of next week (26.09.2021).
The group buy is only made when a minimum amount of 10 boards is reached and payed.
The next possible qty is 20 of each pcb. In this case I will donate the carry-over to diyaudio.
Shipping price is for one pcb set.
DHL EU shipping by registered mail is 8,89€.
Outside EU 14,89€ with delivery time >30 days (otherwise 3-5 days UPS for around 46,99€)


Please answer here with your reqirement as follow

FC-100: qty
FE PSU: qty
Screw Cap Rectifier: qty

and send me also a PN with the same information and your delivery address.

I add only paid pcb´s to the order list.

Thanks!

BOM
--------------------------------------------------------------------------------------

Microsoft OneDrive - Access files anywhere. Create docs with free Office Online.


Schematic
--------------------------------------------------------------------------------------

FE PSU
Microsoft OneDrive - Access files anywhere. Create docs with free Office Online.

Screw Cap Rectifier
Microsoft OneDrive - Access files anywhere. Create docs with free Office Online.

--------------------------------------------------------------------------------------

Howdy..... Apart from the fact they sound awesome, I love the look of 4 bar speaker grills (like the one in my avatar on the left).
They really don't seem to bee that popular in PA sound systems and are far more common the car audio world,

I have used them before but this time I want one for an 18" subwoofer and am very quickly beginning to realise that the bigger these things get the harder they are to acquire.

I found one supplier in the US for the 18" version, but unfortunately they don't ship outside the States
https://www.ddaudio.life/shop/gr18-bar-grill-18-7021?category=38#attr=7440
Even if they did, it's still not completely perfect, l am in the EU and there are Customs charges on anything imported from outside .

Anyway, my question ---->

Does anyone know where l can get these......?
Preferably from inside the EU, but "needs must" as they say, I will import it if l have to.

Thanks in advance..... I really need this sh!t in my life......Help !!!



Databass/

When you spend an hour moving somethings around to make it look nicer and standardize wire colors. And you turn it back on and it’s humming like crazy. So you undo all your changes and turn it back on and it’s just as loud and you wonder what you screwed up. Then you realize you forgot to plug back in the input source and your initial changes were probably fine all along.

I've been working on a design that compares two sets of signals, and then uses the product of  those signals as an error signal. Simplest way i can think to implement this is just use 3 op amps, but i have a very hard time believing that there isnt something that already exists that does this. Any ideas?

Hi dear members I am chasing/hunting down a buzz in the speakers that seems to go down (still present) when touching the metal stem of the volume potentiometer. Connecting the metal casing of the potentiometer to ground does not seem to make any difference.

This unit has been recapped (except) FM board. New transistors installed, rebuilt power supply also.
No matter what input is selected the problem still persist, no signal.
No wooden cover, metal bottom and casing, I tried re-installing them and no difference.
The positive of the main bridge rectifier H009 has 0.5 VAC residual. It could be a ground loop or some noisy transistors...do not know. When you touch the potentiometer metal stem (volume) the buzzing goes way down. Also it is an intermittent problem.
Faceplate, bottom cover & top cover are removed.

Hello. Accuphase P-102 here. Intermittent fault, like scratches in right channel, resembling the sound of loose interconnect wire. Bias and DC offset are fine. No visible reasons, internals are clean and free of dust and rust . Power supplies are good. Schematic / Service manual would be highly appreciated.

granite speaker boxes i make them better an cheaper then aurora accustic

i have made 3 granite box speakers first one i did 15" L7 solar kicker it hit so hard that everyone that heard it couldent believe what it was made from

PCB's for the Hawk A18 to be used with a higher supply voltage (up to 40V). In order to do this the original 78L and 79L regulators are replaced by descrete regulators that are very low noise and low drift.
This also enhances the dark background and precision of the DC and servo loop.

Due to an cancelled project by a client, I can offer these PCB's for a very low price: 3 euro each.

Send me a PM when interested.

Amp came in like yeah....big damage, blown rail caps, burnt PCB and so on.
I took this one just as I challenge if I can fix it...
I've fixed a lot of stuff, I know doesn't seem all that shiny and glossy, but should do the job.
There are burnt traces from the driver IR2010. I'm missing COM and VSS. As I do not have any schematics, i've tried to to follow the datasheet for the driver.

So COM goes to negative rail, but where does the VSS goes to ? Positive rail ?

Hi,
yes, as I wrote, I hear strange radio communication from my speakers. And no, not because of the Austrian beer😛
It's distorted and I can't even identify the language, in any case it's not German, but because of the distortion I can't tell what it is, maybe English, but not understandable. And it seems to be a standard text that is repeated again and again.
But the bigger problem is: why am I hearing this? My Marantz SACD player, the Iron Pumpkin and the Scryer are switched on. It's weird and I'm somewhat shocked 😱
Any hint would be much appreciated.

Hi,

My friend has removed the MC module from his Quad 34 pre-amp to mail to me to convert it to MM, now that he has sadly inherited an old Rega Planar 3 along with his dad's record collection.

The removable board is only the loading and gain stage of the phono amp, the rest of the phono amp remains inside the amp.

The MC and MM boards have the same parts count and locations, just different values, so I want to confirm what I should use before buying parts because the transistors are obsolete and the cartridge loading at 220pF is inappropriate for the AT cartridge being used.

There are schematics attached. One shows the MC and MM versions, and the other shows the whole phono stage with the MM circuit. As I will be given the MC module there are no parts on it that I can re-use.

PNP transistor - BC214C, propose BC559C (or BC560C?) instead

NPN transistor - BC413C is usually fitted, propose BC549C (or BC550C?) instead

Load cap - 220pF, propose 47pF instead. Arm is RB300 with original wiring (100pF-ish) and cartridge is AT-VM95E. I think a ceramic is OK here (COG).

1.5uF tants - I'm not sure whether using a different type of cap here might affect stability in anyway, so should probably stick with tantalums.

I don't think I need to deviate from the MM schematic regarding resistor values, even with the transistor subsitutions, but please correct me if I'm wrong.

Any advice welcomed.

Thanks,
Glenn

I have one Ampeg SVT-7 PRO where the IC U2 (ICE2A165D) burn out. I have replaced it & even resistor R46. When power on the unit , burn out against.

. Is there any one have this issue please.

Any advise

Thanks

I am trying to get a basic dial in for my Eminence 2002 CD.
https://www.parts-express.com/pedocs/specs/290-448--eminence-psd2002s-16-spec-sheet.pdf
Using it as is just over powers the 15 Inch Gama and the 8 inch full range.
Im using a 22 ohms in series and 6 ohms across. Using the L pad calculator on Rod Elliots site.
https://sound-au.com/articles/l-pad-calc.htm#s1
I get a value off -18.42 Db
Why these values well cause I have them on hand.
Even at this level I still feel its over powering the other drivers.
The other drives are all above 96 DB. So In my mind I had thought 104-96= 8
So that is the number I started with -8 Db. But it only started to get close at -18.4 Db.
https://www.toutlehautparleur.com/media/catalog/product/datasheet/eminence/GAMMA-15A-8.pdf

Does the horn used impact the SPL ?.
Waiting on my Umic 1 to do a better job.
Just curious to know how others have configured their CDs. What kind of DB drop do you land up with.
If it matters its an Eminence Horn. Don't remember the exact model.
Have been lurking on Pi speakers forum to see if I could find any info.

Hi,

A few years ago with help, I built Torels Gravesen Audio Technology Classic 3 way.

I really like the speakers, particularly the midrange but I long for a more body / bass. I've tried to add subwoofers but I couldn't get them to integrate successfully. It does seem a waste to sell the drive units for pennies, ideally Torels would have a design that uses the same drive units but with an additional bass unit, but I think his larger AT designs use different drive units and are a lot more complicated build, that I don't have the skill to build.

I'd like the look of his fussion or the loudspeaker designs, with 15 inch drive units but I'm not sure if the horns would be too aggressive for me. I've heard 25k plus JBL speakers and thought they sounded great but the high end was very slightly toppy for my liking, so I'm worried Troels design could have a similar issue. I've grown up listening to my dad's Leak 2075 and loved the natural effortlessly bass that is so different from modern small drivers, as if they are trying to over compensate.

Does anyone have any suggestions for me please. Or know of any designs where I could just add another bass unit in a new cabinet.

Thanks for your help.

Hello,I want to have some advice.
I am thinking to buy affordable vinyl player.
When I look on auction site,there are several good condition cheaper ones,Pioneer XL1550 and some Victor ql series etc. Under 200usd.
I will build phono stage so I don't need it on turn table.
I am completely noob for vinyl player so I want to know it's good idea or not.

hope everyone havin a good day.

Lets say we have an amp that outputs 20watts per channel and we want maximum amount of bass possible with the speakers mentioned below:

there is gonna be 2 big fullrange drivers and 2 tiny fullrange ones that are gonna be crossed over to create a bass roll off @ around 100 or 200hz. in a no crossover situation when we wire these to give a reasonable nominal impendance we either give both big and small spkrs 5 watts each which is not so good for the max bass output we want.

my question is does blocking the bass from the small ones with a cap (which would raise impendance @ those blocked freqs in the small ones) causes the bass to be lost or simply those bass freqs that small ones reject gonna be forwarded to the big ones?

Has anyone tried the GPA 604?

https://greatplainsaudio.com/wp-content/uploads/2016/06/604_8H_III.pdf

bump

Anyone have specs on the transformers in a Pilot SA232? I’d like to start a clone build of this unit rather than search one out and refurbish - but locating transformers is the starting point / gating decision point. Thanks!

I was able to pick a nice B&K Pro 10 ( there is a PRO-10mc and also a Pro-10 MC-101 ) the one I got was the 1st version

It sounds amazing, but there zero information out there

There is 2 op amps, and the owner gave me the owners manual

What do you guys make of the design ?

After trying out a couple of projects that involved making MLTL speakers that are wall mounted (like this one ), I started thinking about other potential ideas for our living room.

I was very surprised by the performance of the 6.5" Poly cone woofer and the 1/2" mylar tweeter (that I bought some of from Parts Express a while ago, but they don't stock them any more) in the MLTL enclosure, but unfortunately at 24 inches square they're too large for me to use.

I was wondering if it were possible to build a MLTL enclosure with the intent of wall-mounting it with the exit port of the transmission line firing up to the ceiling (the kids can't leave a mess on the ceiling...so far...), but where the available width of the box would have to be about 8 inches. The height of the enclosure isn't really a concern, so I was hoping if it would be possible to make a narrow, shallow yet tall enclosure.

The provided T/S parameters are as follows:


Here is the mounting information:


Thanks in advance for your help and guidance!

Hello dear
Does anyone have the service manual of SONY CFS-W600 in Japanese language?
I need schematic diagrams only for radio board. ( tuner board ).
Please send me to my email address

fardodreza@gmail.com
Thank you.

This popular gyrator smoothing choke works well in a positive supply. Now I'd like to use it to smooth a negative bias supply where the positive of that is referenced to HT ground. So can I just simply put this "two wire" gyrator in line with the bottom negative wire instead of the top wire? Like I could if it were a real choke? IOW simply flip it upside down. are there any polarity issues with doing that?

Hi All,

I am looking for the W-Input module designed by Tomi Nihtila. If anyone is willing to sell the module, id be interested to buy.

Thanks and Regards,
Som

In the US, speaker sizes are typically referred to in inches... 6x9s, 8s, 10s, 12s...

Is this still done in places where inches aren't commonly used? If not, what are the commonly stated sizes used in conversation for the speakers from 6x9s to 15s?

The bias in one of the channel is not holding.After a few seconds the output start to over heat.I see about 1.567v pulsing on the output terminal .

I did not find anything bad in that channel.
Any suggestions?

If it works, how much would I get at op? Any correction needed in the scheme? Is it a good tube? What's it's French or sovjet equivalent? Just all these 👍

So per my subject.. I am curious if there is anything better than.. or newer and more modern than WinISD, TermPro, BassBoxPro, etc.. that offers more box designs, and ideally can spit out at least cut lists, but more so gcode for cnc machines?

Looking at Term Pro which seems to be about the best "all in one" in terms of design, port design, and cut sheet list.. it's not bad (though their site is STILL so damn 1990s looking.. holy crap update the site!). I can't figure out if that $250 covers unlimited updates.. or if its like 1 year of updates, then you gotta spend another $250 for minimal future updates or what?

WinISD isn't bad, but it leaves a lot to be desired. Does the job, but you still got a lot of work after.

I was hoping by now, with the way AI is proliferating every aspect of software, that there would be something available or.. maybe in the works, that allows for good box design with a variety of types/styles, and can provide at least a cut sheet for wood, assembly, etc.. but best would be some sort of CNC gcode output option so that project CNC machines (e.g. the $500 to $5000 machines like the OneFinity) could be used to cut the wood perfectly.

Or.. do we need to wait for ChatGPT 5 and hope it is able to do all this via a textual query to describe the box, holes, ports, drivers and then spit out gcode?

I have had problems with noisy phono circuits ever since I moved into my house. There is a radio tower like half a mile away, that I can see clearly from my windows, and it comes over my phono stage, and my guitar amp.

I also have no grounding anywhere in my home. The outlets have a third prong, but testers read "open ground". I rent, so there is not much I can do (it is a standalone home though, no shared wiring). I often have noise/hum problems in concert with my radio pickup problems.

If I had properly grounded outlets, would that solve or improve my RF and noise issues? Or are these things all unrelated, and I just got lucky?

I have a pair of Beyma TPL-150H's being unused. I have lots of speakers and amps, but what I need is near-field speakers behind my computer desk for streaming. I hope to circumvent some of the usual requirements by active crossover/DSP/EQ'ing with dbx driverack PA2 (also laying unused), kind of active mini-me version of Spatial Acoustics X series open baffle with one woofer. A decent woofer choice that will take well to EQ'ing the bottom end on a smallish open baffle?.....Or just abandon the idea? Looked over previous posts on Beyma, but no project was quite like this.

Starting a build for a Klipsch Belle, which is similar to the famous La Scala, only larger.

For this project, I'm using 25mm American Walnut on euro birch ply. The dims will be adjusted to accommodate the thicker panels (up from the original 3/4 inch).

Checking out the Crites 15-inch woofers also.

Top horn is a work in progress.....maybe a Bill Woods conical 300Hz, like that used in the Oswalds Mill range.

The 3D rendering pic of the La Scala below is not mine. It shows an interesting take on the original design, by porting the two cabinet sections together, then operating as a bass reflex.

Should be fun.

Kia Ora folks
Just wanted to say hi as I'm a new member here!
I'm based near Queenstown NZ and run a small (one man band) CNC routing service. I have experience in helping people to create there sound systems and have re-modeled various designs adding loads of features into the cad models and then automating the cutting of all those features on the CNC. I usually work with the customer to create a custom look in the bracing to make their subs stand out. I can provide both flat-packed and fully assembled options.

I am here because I want to connect with speaker designers and builders and to offer my services in this area. I'm also looking to chat with designers about licensing agreements for re production as sometimes people have been asking me to re produce jobs that I have helped private customers with for personal builds.
I haven't re-produced any yet but want to go about it the right way!

My website is: https://zone2.nz/design-cnc-cutting-service/
My Facebook is: https://www.facebook.com/zone2.nz

Thankyou! Look forward to connecting with yas!
Dan

Good afternoon, could someone tell me where I could get the vu meter for a Pass Labs x250. Thank you, greetings from Argentina.

Up for sale is the Wayne's Burning Amp 2018 Linestage, see below:



Asking EUR 50 plus shipping from the Netherlands.

Does anyone know what 4" fullrange drivers these are?
The speakers are Synthedata Dbox Mini Max powered by internal lm1875t amps.

They sound good with plenty of low end for small sealed cabinet, but lacking high end.
Hoping to swap them for better drivers suitable for these enclosures.

I have three of these, and I am scouring the Internet for a fourth. I would buy up to 2 of these at $150 each, new or used. Please PM me. Payment is Paypal.

Hi all, this topic was found but closed about 10 yrs ago. Hifiengine has the service manual / schematic for the NA-590 II, but I am looking for the NA-590.
I have one that is putting out 37v on right channel.
Hoping for a parts list with values and schematic. I am aware that I can order one for about $20 Cdn, but that kind of money can buy me 3 eggs, so thought I'd try here first as well as discuss the mods that were done.
@adason would you still have something from 10yrs ago?
Thanks

For sale are 4 stasis output boards and a pair of input boards.

Also, PSU board with extra capacitor holder (white board).

Asking $40 plus ship from Houston, TX.

I bought these from my locate electronics store but they were too big for my chassis.

Just want to get my money back.

$45 shipped Conus.

Hi All,

In an amp design I am working on, I am contemplating running some 500mW TO92 devices at around 100mW dissipation, This is more than I am generally comfortable with for these devices, but still well within the manufacturer's derating curve. Given it will be running in a class A amp enclosure, the junctions could reach up to 95degC assuming a very extreme case of 70degC ambient conditions and the 250deg/Watt junction to ambient thermal resistance. I note that such conditions would likely see failure of the output devices anyway but I like to think about extremes.

Anyway, I was interested to know how much this might shorten the component life. I have heard the rule of thumb that lifespan halves for every 10 degrees of temperature increase, but this did not help much as I didn't know the starting point. I did some googling and wasn't able to find much except the attached document. Although it seems to be a specific use case and is for power transistors I thought the below graph I have extracted from it might be a good analogue and of interest to you all. The takeaway for me is that a junction temp of 95 degrees is unlikely to shorten the lifespan to anything I need to worry about (MTBF of ~1000 years!). For the detailed specifics refer to the PDF itself.

If anyone has some additional quantitative data like this please share!

Enjoy!

SOLD
One pair of JBL LE8 driver. These are the rare original 16 ohm version with Alnico magnet (not the later LE8-T or LE8-TH). These were reconed by JBL a while back and have just have new foam surround installed. Serial numbers are 13359 and 13363, so they were bought at the same time. Still have the JBL box that was used when returned from recone. Ship from US 94022.
Note that there are some very slight dent on one of the metal dust cap. It doesn't show up well in picture. One of the black plastic cap is missing from a terminal (as shown in picture). Does not affect functionality,
Please PM with offer and ZIP code (for shipping quote) if interested.

I took the chance to make an opening thread. 😀

There are almost no examples of amplifier or preamplifier design using this option. I have experience with two designs so far.

Zero Signal Planes are PCB copper pours, which are connected to the ground at a single point. That way, there are no loop areas which could add EMI induced noise to the signal. Only downsides are that you have to use more expensive 4-layer PCB and there will be higher parasitic capacitances between signal tracks and ground.

Here is an example of output noise from my latest amplifier (measured with calibrated LNA), that will be published here in a week or so. Mains transformers are some 10 cm apart from the signal tracks, yet induced 50 Hz noise is only 700 nV.

Hello,

I trying repair an amplifier

Problem is treble amp offset reads -32 VOLTS when COLD!!

amps bias is fine

- When amp heats up dc offset drops to +- 50mv, this is withing manufacturers specs

- Dc offset bounces a lot when hot, from 50mv to 10mv then to 70mv and back to 50mv

Bias is stable when hot

Manufacturer specifies that amp should be measured hot

- when this amp is working normally, offset is max 200mv when cold. I have excatly the same amps which work normally

- offset trimmer pot is tested and ok

- the whole amp board was resoldered just in case, looking for bad connection, no changes

- When amp is hot and its turned off for a couple of seconds, DC offset is immediately -5.00 Volts from -50mv. And starts super slowly rising back to 50mv

What are the main causes for DC offset to be so high when cold?

I hope it's made of vinyl

Hello everyone, is there any reason I couldn’t have a capacitor multiplier with multiple pass elements?

I’m in the early stages of designing a power supply for an amp i’m working on where the B+ can be adjusted. I was designing one with one B+ output for both channels, but now i’m wondering if I can get better channel isolation by "slapping on" another pass element running off the same driver, since the pass elements have high impedance inputs.



I could run two separate circuits off the main filter cap but then I would have two voltage pots which I prefer to avoid.

Hi, I just built large, bulky speakers that need to be away from the walls for listening and closer to the walls when not in use. Need something that will be kind to recently refinished oak floors. Wondering if a full layer of wool felt might be good. But maybe spreading out the footprint is bad and a four foot approach would be best. Any thoughts? Unless it matters I am looking for a less expensive fix. No esoteric $300 speaker feet. I read about people using cut up wool dryer balls. What is the most sensible and effective approach?

Hi all.
I have an ASUS Essence ST in my old pc and and STXII in my new one
Would I be able to change the amps from the ST to the STXII for a better sound. The ST has very tight bass while the STXII is quite muddy.
Thanks

Hello forum members hope all is well
I know there are numerous headphone amplifier designs (very nice ones in the DIY audio store) plus I am a big fan of the JLH single ended Class A design but I have become very fond of this design and the PCB layout (no surface mount and big solder pads for us oldies)
Also to my ears sounds very nice, I have decided to make a test bed for tweaks and document on this wonderful forum

I decided to make my 1st module with good quality budget components with a few notes below

1. The op amp is a OPA2134 ( I have used an OPA2134 audio op amp here for best budget performance) but will try other op amps once completed
2. Matched all the transistors 1st time I have done this
3. Used Jantzen output inductors ( from HiFi collective UK based online company ) 0.005mH Jantzen Air Core Wire Coil AWG20, 0.8mm diameter wire
4. Cardas`s quad eutectic solder in the build

I think this is a very good sounding headphone amplifier sure there are better designs but thought its worth a mention and would be fun to see once built how it compares with other designs

Spec Below

I'm wondering if I can pay someone to design a waveguide for an AMT that I own?
Does anyone know of anyone providing that service?

I've taken delivery of a new mini PC which comes loaded with Windows 10. I don't like the way that Microsoft is always trying to sell me something. I've also had my Hotmail account hacked from 3 different countries - Russia/USA and the UK - I live in France. Luckily I hav'nt suffered any financial problems.

I did for a few years have a secondhand PC using a Linux system (I can't remember which one now) It was lovely not being bombarded with sales pitches but when I had a problem it was difficult to find anyone here in France where I live to sort out the problem, apparently in France only 1% use Linux. I would seriously consider Linux again BUT I only want a KISS system not one loaded with programmes I'm never going to use.

Unlike many I live a very simple online life - I have absolutely no need for social media of any kind. I don't live my life online. I use the net for nec. communication - tax/health/buying/selling and bookmarking info, one of the very real benefits of the net. I don't stream music because I have virtually everything I need. I should by Christmas be able to start digitising my collection of LPs/CDs and offload all that gear leaving me with a couple of mini PCs, one dedicated to stored music just using h/phones. Seriously thinking of living in a motorhome rather than building a house. Stripped down but comfortable living and moving around Europe.

Re. online security I've managed after lots of hassle to free myself from Avast - always trying to sell me something else, if I bought into all their subscriptions it would have cost me hundreds of Euros per year. This company even had the cheek to take another year's subscription just short of 5 weeks in advance. I would really appreciate sound advice on good online security software, paying is not a problem but no more constant hassling to buy.

The mini PC is a Pantera Pico
Intel J4125 Quad Core 2.3GHz CPU
Dual-band WiFi 2.4GHz/5GHz 422 Mbps
512G SSD
8GB LPDDR4
3xUSB 3.0 / 1x USB 2.0
HDM12.0 port
audio jack
m.2 SSD + MicroSD Expansion slot

My existing mini PC will be used only to store my music kept permanently powered on, important when using SSD and when I have downloaded the software to record the music will not be connected to the net.

I use Yahoo as primary email (had no problems) I don't like Hotmail, I also have a Gmail account, I'd prefer to use that as back-up instead of Hotmail.

What Linux KISS programme should I consider and what online security software, very grateful for all sensible answers.

purchased this to use with my Streaming Dac based on the protodac TDA1387 in hopes of a better clocked i2S. I ultimately preferred the Hifiberry Digi2 Pro inbetween the PI and the protodac cleaning up the timing and Jitter. Its essentially new. Uses the AKM Chip 4137EQ

25 shipped Cont USA or entertain trades for a Kali reclocker or Ian variety reclockers and cash on my end. Let me know.

This one passed me by a couple of weeks ago.

Katherine Anderson of the Motown group The Marvelettes, born 16 Jan 1944 , died 20 Sept 2023.

The Marvelettes, although a great group in their own right, always seemed destined to reside in the shadow of The Supremes.

​

Well the other day my beloved trusty Tektronix 2430A greeted me with a self test fail. 🙁 Of course this always happens in at the most inopportune moment, as usual.😀
I am sure others have seen this issue before me. I am trying to describe what I did try to get the scope back to working order, perhaps this may help someone who is facing the same issue. As it turns out the very special NVRAM chips have finally lost battery charge and corrupted the cal data checksum. The offending chips are U664 (Cal Data) and U350 (Waveform Data). Both chips in my scope were Dallas DS1235ABW-120 vintage 1990. I would not want to complain as these chips kept data much longer than what they were spec'ed at. 🙂 I found some old new stock on ebay with a fairly 'recent' mfg date and bought some. Despite the corrupted data in these chips, I decided that I may have nothing to loose if I tried to read these chips in a programmer and perhaps pre-load the replacement chips with whatever I can read out of the old ones and perhaps reduce any calibration efforts. As I did not have a programmer, I turned to ebay and bought a cheap one Model TL866CS. I removed the main-board for convenient access as the offending chips were not on sockets and needed to be unsoldered, I installed sockets for the new chips and would recommend that. The old chips still contained some data got loaded into the new chips without problems. Then the pre-loaded chips were installed on the sockets and the main-board was installed and reconnected.

Then as part of the calibration procedure, jumper J156 must be removed to enable extended calibration feature. After successful calibration this jumper should be put back.

I believe I read that it is advisable to operate the scope only with installed case as the air flow is as ist should be, otherwise if the scope is operated without the case in place it may not have sufficient airflow and some chips could die due to overheating.

The calibration is very easy, one needs a decent variable lab power supply that can provide up to 20.0V, A few BNC cables and adapters may come in handy also.

With the enabled calibration features and warmed up scope

Initiate EXT CAL

Run ATTN cal, and follow on scope screen instructions.

Run SELF CAL and turn off scope and turn back on.

Run TRIG cal, and follow on scope screen instructions.

and turn off scope and turn back on.

Run REPET cal.

Run SELF DIAG to confirm the errors were cleared and the scope now passes self test.

If needed repeat calibration as per above.

This should clear the following self test errors

3000 SYS RAM
4000 FPP
6000 CHECKSUM-NVRAM
7000 CCD
8000 PA
9000 TRIGS

Now, I am a happy camper again 😀😀😀


I like my Tek Scope and hope it will remain in service for a very long time.

In 1980 I built the Maplin lateral mosfet amplifier.
This was based on a Hitachi datasheet lateral mosfet amplifier schematic.
It worked well.

A few years back I decided to see if I could modify it to use irfp240/9240.
So designed a new pcb with new outputs.
I added a dc offset pot, Vbe multipler and decoupling of front end to reduce hum.
Not a bad sounding amplifier.

Both compression drivers above are arguably the most popular for DIYers. D220Ti is the darling of Econowave, and DE250 is used extensively in Gedlee Speakers.

Having built the Econowave I wanted to get that "extra smoothness" so popularised by DE250 reviews. After finding out that they had good polar response with Econowave, I bought a pair and lived with it for a while. Indeed they sounded very smooth.........But after a while I thought D220Ti is more resolving and DE250 is too "mellow" ?

Anyway after multiple swap between these two drivers I decided to test them using tone burst (because distortion test is boring and DE250 won the CSD.. he..he..). Read about Tone Burst test here.



SO the key summary:

1.5khz - 6khz: DRAW, they are practically the same although DE250 had small win. But not enough to differentiate at all.

6.5khz - 8.5khz: Winner: D220Ti. DE250 is having a hard time to return to zero amplitude. I think this is a major factor why D220Ti sounded more resolving (being metal?). At 7.5khz the DE250 output is quite deformed.

9k - 13k: DRAW, D220Ti a bit better

14k - 15k: Winner: DE250 by miles D220Ti falling apart at 15khz

16k - 20k: Winner: D220Ti picked up and left DE250 behind. The tests were not audible to my ears anymore.


So the conclusion is D220Ti performs better in Tone Burst test. The test itself could be improved by less increments of frequencies to cover more differences but this one should be enough.

D220 is confirmed to be more resolving, and while DE250 is smoother it is at the expense of resolution and accuracy.

The good news is D220Ti is much cheaper. The bad news is ... I've invested in the DE250s

🙂

Hello gentleman. What is the purpose of the output resistance ? How does it confuse or help us?

When first turning on my IRS2092S amp, it's fine. After turning off the amp and back on within 30 seconds or so (with volume up), there's a popping noise. This sometimes causes pulsating popping noises. When turned on with the volume down, there's no popping noise.
I do have a 100mfd non polarized capacitor from the output of the volume control to the input of the amp.
Any way to avoid the popping with the volume up?

I owned an AIYIMA A03 amp below.
https://vi.aliexpress.com/item/1005004563887441.html?gatewayAdapt=glo2vnm

It will be great that it can produce more BASS than this from its Left & Right channels (not from subwoofer out). Is there anyway I can get some more bass from it?

My speakers are Two Way 5" Phillips speakers & supply voltage is 19V, Signal from Phone Bluetooth.

Thanks

Hi, working on a vintage phono stage, but cant find any info on this capacitor? Anyone who can help translate its code to modern equivalent. Thanks

Hi all

I’ve got an old school DSE A2760.
I decided to remove the pre-amp module and make a few mods following the guide here.

https://www.overclockers.com.au/wiki/DSE_A2760_Amplifier_Modification

Now that I have put everything back together I’m actually getting no audio output 😭

Looking for support on what I should be checking to fault find. I have checked across the whole underside of the board. Nothing looks suspect.
Amp powers on fine. Only volume control I’m using is via the PC and verified input cabling is fine.
I can actually hear audio but it’s very very quiet. Ramping the volume on the pc makes no improvement.

Trying to build this Schematic, do I need Compensation? Or is it gonna work without that, or any changes u suggest

Hi,

I am designing my first crossover using Xsim. I am using Scan-speak D2904/710002 and 18W/4531G00 for a 2-way bookself. Both drivers are 4 ohms.

I notice that the impedance of the midwoofer drop lower to 2 ohms after my crossover. I know that it would be hard for the amplifier, but the impedance is smoother without that two humps.

Would this be a good design? What would you improve?

Here is the impedance graph and design