Have an interst in diy speakers of all kinds.
Had made 3 ways based on scan speak with visaton woofers, with added weight to the cones. Why? Well I prefer closed bass systems.
Recenty changed the electronics from Canadian/ English to Chinese.
Now experimenting with 4 way active speaker setup.

I bought a pair of these new unused, just out of interest. EPOS seem to have a following and they seem to employ simple XOs, so I am hoping these are quite easy to implement.....into what I don't know yet!
Anyone know who made them?

Part no. ELS3mb01
They're a 4 ohm driver. Cast chassis. Not sure if the cone is aluminium, though it doesn't feel cold enough as it's been sat outside?! Maybe a coating.

Nice looking things and seem well built.
TS Params to follow.

Im cutting out the mid driver recessed and I've finished my first pass and something doesn't add up. It looks like the mid driver is too close to the tweeter compared to other peoples travelers. I've drawn out where it's supposed to be in the end and drivers are suspiciously close. Is my math not mathing and I'm crazy or did other people move their mid driver down or did the diamater of the tweeter change????


Below are the plans I'm following

Bellow are examples of other peoples travelers where there seems to be atleast half an inch gap compared to 0.2 inch mine

I'm building an enclosure that holds 3 existing PCB boards that are streamers - basically small pre-amps that you can stream to. Mostly an assembly challenge to house the 3 PCB boards, add a single power switch, a 5V power supply, and 6 RCA terminals for inputs on the back panel along with a way to connect the plug to the mains.

I'll need to run wires from the RCA jacks to the PCB boards and I'll need to run power from the supply to each of the PCB boards.

1. For the RCA input signals can I just use single stranded wires for these connections or do i need any kind of shielded wires or keep them in pairs in any way?
2. For Power from the supply to the pre-amp PCB boards I assume i can just use a single positive 5V wire and a single ground wire with a gauge that covers the expected amperage?

While i'm asking...anyone know a good source for where i can get a good regulated 5V power supply for this that I can install in my enclosure?

So we have done a few of these over the last few years, but im hoping this could be the best one.
I will continue to repair these and other amps because i enjoy doing that side of it, but i want to start concentrating on learning more, and eventualy,if i ever get there, build my own from scratch.
But for now im taking a good condition 3020A(i made the mistake last time of converting one with faults, so this has been servied first) and going to convert it all to gold plated, change the rear terminals to gold plug ins, total recap, remove the driver stages and convert it to Lateral FETS.
I did convert some amps some time ago, but it was either with gold, but BJT's, or with TIP 35'S etc, but never all in one
so this one will be all of that but in one package.
I know NADS are like marmite, you either do or dont like them, so i guess this is for those who do.

STEP 1
so to start with the rear has to be converted
so the inside has had a first clean, it will get another later
the rear has been stripped, cleaned and resprayed
I have taken an old terminal assembly ,stripped it down and converted it to gold plug in terminals

STEP 2 will be to strip out the old transistors and get to work on what heatsink will be used and start the board conversion for the FETS
STEP 3 will be a second clean and recap
STEP 4 will be to do a dry run with the FET fitting
STEP 5 fit the FETS
STEP 6 mod the circuit
STEP 7 fit all the rear terminals
STEP 8 Testing
STEP 9 If all working ok, long soak testing
STEP 10 respray the main cover and assemble

Hi,

In my Project to fully recap my NAD 356 BEE i noticed, that the amplifier is distorting in the right Channel. Its barely noticalbe in usual hearing but when i run a freq sweep it is clearly noticable.

So i checked the Amp and noticed that one diode in the feedback cuircuit is damaged. It let run the Signal both ways which it shouldnt and the MM diode checker also says, that the Diode is blown.

I identified the Diode "D12" in the service manual and the it just says "4.7V 500mw"

I was looking for the diode on Digikey and found a replacement but im a bit confused what Diode i should pick.

The "4.7v 500mw" diode is available in different types that have different values in the diode impedance and back leakage etc. and im not shure if i have to be careful here to choose the right one with a specific Value.

So i thought a "Vishay 4.7V 0.5W" with the "lowest" 19 Ohm impedance would be the best choice. But it is available up to 100 Ohm and the

"Current - Reverse Leakage" and
"Voltage - Forward (Vf) (Max)"
values are different in the multiple available 4.7 500mw Diodes.

Thats the one i choosed first

https://www.digikey.com/en/products...iconductor-diodes-division/1N5230B-TR/3104101

These are the available Options :

https://www.digikey.com/en/products/filter/diodes/zener/single-zener-diodes/287?s=N4IgjCBcoGwJxVAYygFwE4FcCmAaEA9lANogAsYYAHHAOwgC6+ADqlCAMoYCWAdgOYgAvvjgAmAAyIQKSBhz4ikUmQB0tAAQA1RizaQQAVV7dUAeQBmAWWwBDAM6Z02YfjBwa02fLyESIKQYREDEwCQRoGTQsXyVSAFYJCQ0AWwB1XRBWdmNTSxsHJxdggFoxL2iFP2UQeMYhYPKarW57AAtbAE8NABNuAh7sDTVaLQ1EiRSAd0yYaW4e9hKwkD12VZBUTuYXA2EhIA

So do i have to look close to these values or is any of the 4.7v 500mw fine?



EDIT:

Entire schematic / Page 17

Thanks and Cheers!
Silas

I was watching the TV (as I have my Marantz amp set up with two tannoy mercury speakers, paired up with a digital audio converter) and the audio cut out.

Just as the audio cut out, I heard a click/clunk. The same sort of sound you hear when you power the amp on.

Could somebody possibly help with this?

I have been taking measurements this week of a dipole mid planar. I have been getting this crazy phase shift that I thought was just from it being a dipole. I put a back cup on it and its still doing it. I then tested another speaker and its doing it for that speaker as well.

I must have something screwed up in my settings. Can someone please take a look at my settings and tell me what I have input incorrectly get this crazy phase shifting happening?

I'll attach pictures of the phase shift and my settings

I'm attempting to design a feedback loop for a self-oscillating amplifier (for fun and education). I wrote a script to calculate the parameters outlined in Bruno's article, but upon simulating the feedback network transfer function in LTspice, the oscillation frequency doesn't match what I calculated (it's much higher when the entire FBN is simulated by a VCVS and much lower when the output filter is physically simulated). Does anyone smarter than I know why this might be?

For reference, the feedback network uses a KHN biquad for the proportional and derivative (lead compensator) part (I'm summing the LP and HP outputs), and there's a low-pass MFB filter for the integrator.

I've attached the LTspice file below, and you can open the Python notebook in Google Colab.

Edit: The notebook won't run in Colab I think because there's a conflicting scikit dependency, anyone is welcome to run it locally though!

The sony cdx-t69 6 disk cd changer in my cars trunk makes a loud buzzing noise (sounds like an overtorqued motor or skipping gears) whenever its on disk 1. 2-6 work perfectly but whenever its on 1 it stops working and the cars radio says "push reset". I opened it up and located the general source of the noise (photo attached), but i have no idea what im doing or what to look for. Any advice/fixes?

So. What started out as upgrading Tridents to my old dual mono 9018s in the previous thread here spiralled rapidly out of control- thanks Franco Largo for providing the temptations and suggestions for optimisation.
To be honest its been at the back of my mind for 2-3 years but a bit of free time has finally allowed me to get this project off the ground- The best DAC I can conceive of and build.
An added impetus was noticing its a bit of sunset on Twisted Pear Audio, don't know when Brian will finally shut up shop. So I took the plunge a couple of weeks ago and invested in a 9038 and Mercury while they are still available. Delivery due tomorrow or Tuesday I reckon, looks like they arrived in the UK yesterday accordingn to tracking. Nice!

The design plan is:
2 proper Modushop Chassis; 1 for PSUs, 1 for DAC/Music server
DAC:

1. Music served by my old BeagleBoneBlack,
2. Music library stored on onboard SSD
3. Source clocking using my old Hermes and Cronus.
4. USB hub to allow connecting more storage to the BBB.
5. Buffalo 9038
6. Mercury IV
7. Option on Analaogue output filter, something like 6 pole.

Regulation

PSU
8 Transformers
12 seperate supplies
3 umbilical connectors betweeen PSU and DAC:

So thought Id share the design and build journey, a sort of last salutory swan song to the Twisted Pear digital products. Hope you enjoy, (and it all works out as planned!).

I am very happy to join the DIYaudio family.
I am learning to make audio equipment and hope to learn relevant knowledge here.

I have a magnavox mystique model 1ST605R and I need to do a cartridge replacement and some repair work on the radio board (can't get FM to work). However, I can find ZERO on this model number. I even looked to the Sam's Technical Library and there is ZERO in the 1ST model range. Can anyone help me? I know it needs a new fantail cartridge, but I really need the number for this item as they are NOT cheap and there is no returns. Anyone have any help for me?

Im a 17 yo who recently bought a car 6 years older than myself. It has a bunch of cool stuff related to audio, and some of it needs repair, which is why im looking forward to chatting with some people who actually know what they are doing 🙂

I'm trying to fix my yba cd2 delta player.

The player works perfectly for 20-30 minutes and during that time track poor cd without any trouble.

After that time, it start having troubles reading and at some point wont even initialize a new cd.

The problem seems related to the spinning motor where it try to turn but won't reach proper speed. If I give it some help it will initialize but after some time it will start skipping when slowing down.

I've found a visual problem on the main board which seem a generic board for the sanyo sf-p1. The diode d116 (circled in the picture) is over heating and damaged the board and traces connecting to it. You can see that the diode is lifted from the board to prevent that but it's still hot enough to conduct heat to the pcb and slowly destroy it.

I would relocate the diode to a bigger one using the casing as a heat sink but I need to find the reason that this happened. The player had been repair for the same trouble couple years ago and from what I can see they only replaced that diode.

The main board is the same you will find on many players of this era, classe cdp .3, roksan caspian, cec cd2100 cd3100, krell kav-250 ... I've found some pictures of these cd players over the web that show discoloration around that diode so I don't think it's a problem only related to the implementation in the yba cd player.

I've searched for a schematic for any of these players and only found a service manual for the classe cdp .3 and it doesnt cover the main board at all.

If anyone had experience with this problem or have a schematic it would be of great help.

Xin chào mọi người. Tôi là thành viên mới, tôi tham gia nhóm để học hỏi và trao đổi kiến thức và cần sự giúp đỡ của mọi người.
Tôi đọc trên diễn đàn nhóm rằng có người có một bộ khuếch đại công suất Counterpoint solid 1E mà tôi có và tôi muốn khôi phục nó. Tôi thực sự hy vọng bạn có thể giúp tôi tìm thông tin về một số thành phần để tôi có thể thay thế chúng.
Thông thường, các thành phần của bóng bán dẫn đã bị loại bỏ và không còn thông tin nào còn sót lại như:
Q2; Q3; Q4; Q5; Q6; Q7; Q9; Q11; Q12; Q14; Q15; Q17; Q18; Q19; Q20; Q21; Q22; Q23; Q24
Nếu bạn có thông tin hoặc sơ đồ mạch của bộ khuếch đại công suất Counterpoint solid 1E, vui lòng gửi cho tôi.
Tôi thực sự hy vọng nhận được sự giúp đỡ của bạn.
Cảm ơn rất nhiều.!!!!!!!

hi!

I have in stock excellent electron tubes ГМ70 / GM70 copper plate
All tubes NOS, close data codes.
Each tube was tested.

1) GM70 copper plate, matched 5pcs, price 600 $/quintet SOLD

2) GM70 copper plate, matched 2pcs, price 260 $/pair (i.e. $130 each) SOLD

-------------------
PayPal payment

Best regards!
Olexandr
Kharkiv, UKRAINE
skype: OAA-1974

Hi all!

I'm having trouble with an Audio synthesis DA-X. It's not locking on anything. There is an,,,? error light that comes on when there is no signal and after that goes out it's supposed to lock but the 44.1khz led keeps blinking and there is no sound. I traced the digital signal all the way through the cs8412 input decoder and to the input of the pmd100 but there is nothing on left and right outputs. As soon as I turn the dac on both outputs measure at about 5ohms to ground but both soft and hard mute pins are low. I was wondering if it was somehow possible it was accidentally switched to the maximum attenuation.

I've been all over the Internet looking for a good answer to lowering the voltage down after The rectifier tube. I have a 5U4GB rectifier tube in A 6l6 GC PP amplifier. 525 on The Plates , 400 on The screen and - 26 Bias. This is with the Rectifier tube in and the output tubes out. Also I have a 100 ohm 1 watt resistor going to the second can getting extremely hot. I'm guessing that it is the one lowering the pre Amp section down to 400 At the second can. My Filter Cans are 500 volts 50/50 and 32/32. A little bit more filtering than the amplifier had in it originally. 40 and 20 were in it originally. I'm going to The 50/50 first. Line is At 123 AC. My plan was to put a 10 watt 100 ohm cement resistor after the rectifier tube and before the first filter can. Also to put one in the place of the one getting hot for the pre Amp power on the second Filter can if the first resistor doesn't cool it down to a reasonable amount of heat. I would think that It should be able to stay cool especially with the two 6l6 tubes out. I also put a 1 ohm resistor on the cathodes so I can read the ma of the tubes..I wasn't sure where to put the two 5k Bias pots At. Or if I really need them or not. I have switched over the chassis with this thing and I don't have any type of wiring diagram for it. It came out of a 1960 Whirlizer Organ and without knowing what organ it came out of the wiring diagram is impossible to find. The amplifier number is pretty much useless in finding it. Whirlizer 501273 is the amplifier number for what it's worth. I've been reading about using chokes also but I don't know if I should go that way without knowing anything about the specifications. Seems much easier to use resistors first to get it under control. It seems like 100 ohms in 10 watts resistance is pretty standard for lowering down the voltage. I've Used 120 ohms Cement resistors At 5 watts before in small tube line amplifiers to get the running voltage down after the rectifier tubes. It seems to work pretty good in them. But A small line amp and this 6l6 GC seem like they are world's apart. I'm also A little concerned with the low amount of bias voltage -26 being supplied. Any help appreciated.

Here i have NOS 500 pcs of 1N4007 manufactured by General Semiconductor.

Price is 0,10€ per diode plus shipping and paypal fee, i have 400pcs in stock.

100pcs where sold so you can buy in quantity of 100pcs.

Thank you for watching.

Hi, will this circuit perform as intended ? . A normally closed transistor relay , that when a voltage is applied on the input it cuts the current flow to the Relay Coil .
The use of it is in a speaker DC detect / protect circuit , Instead of using two Relay's I was thinking this would work . Also for the Relay flyback , will a 1n4148 survive?. The relay is rather small ( 350mH inductance ). Thank you.
Mosfet I'll use something in D-Pak like IRFR2405 .
- Bruno.

I have several new pairs, and a lot used ones. The used ones all come from Arcam A85. The main board of these failed and had to be replaced.
I serviced Arcam in Norway for many years.
The new ones originates from Musical Fidelity. I did some of MF amps also.

New $24/pair, used ones at $20/pair.

Shipping st cost.

Hello.
Tape deck MARANTZ SD 6020.
No play...no record....no rew.....no forward.
Solenoid not working.....
Motor capstan spinning.

All 3 belts are replaced .
Thanks

Hi all,

Simple question for concept. I was looking at designs and it made me wonder about the idea of using an open baffle speaker, something 100hz to 20khz bandwidth that is a dipole, and then right behind it, identical drivers in a sealed cabinet with a little space between the drivers, aligned. The backwave of the open baffle and the front wave of the sealed with opposing phase should largely cancel each other out. Does that leave only the front wave? And the dipole pattern handles the side to side off axis output too? I've got to be missing something here, other than the obvious requires DSP to do the phase and delay to get the effect and the double drivers, etc. What huge thing am I missing?

Very best,

I think I am 'doubling-up' on another thread, but I want fresh new information & opinions.
I've heard that some "Calibration Certificates" are not worth the paper they're printed on.
I've also heard that even a simple SM57 is very good (within a range) 🙂

What kind of recording is suitable as a reference?

I would like to ask you guys specifically which songs or albums you think are suitable as a reference and why.

For example, when evaluating a speaker, one person may say it's the best, while another may say it's the worst. I often think that this is actually just a matter of the music being listened to or the listening habits. There's no way that someone who listens to modern hip hop at high volume and someone who listens to antique chamber music quietly can give the same evaluation.

For myself, I have been using Steely Dan's "Gaucho" as a reference for a very long time. It's a great production, very well balanced, but it's not perfect. In fact, I think that the vocal production on this album is quite poor. However, the reason why I still use it as a reference is simply because I have been listening to it for a very long time. It was my favorite album when I was in college. I feel confident that I can evaluate playback devices fairly well just by listening to the first 30 seconds of this song, which I have been doing consistently for decades since purchasing my first audio system in college. My wife says, "You love this song." but I don't actually listen to it because I fall in love with it. It is rather a cursed relationship. I have several other references for myself, but I think I'll write about those later.

Furthermore, I think that audio forums like this should make it mandatory for users to list a few reference songs on their profile. Otherwise, it would be a waste of time to argue with someone whose taste and listening habits are unknown. It would only lead to the conclusion that it's a matter of personal preference, without any real learning taking place. I believe that information about a member's musical references is much more useful than knowing what kind of equipment they own...

Welcome to this thread about the speakers i'm currently building.
This is my second speaker design/build that i have done.

The goals of the build are as follows:

1. High Wife Acceptance Factor.
2. Should not look like a dull ordinary box.
3. Have a nice flat frequency response.

the project has been going along for some time already, but i have to choose how i am going to do the crossover.
which one should i do?

• passive crossover
• active crossover
• active system with 6 amps and DSP as a crossover

I would love to hear your stories and reasons to choose one of these solutions.

speakers from top to bottom:
Dayton Audio Reference RS225-8 Bass-midwoofer
Dayton Audio DC28F-8 1-1/8'' Silk Dome Tweeter
Dayton Audio PC105-8 4" full range woofer

I have bought a Maplin 100WRMS mosfet amplifier off ebay that hadn't been built, it was still in kit form. As rare as rocking horse droppings !
So I built it up tonight and it worked first time after all these years.
Sounds very good.

Hi. I am a bit concerned with whether or not a cartridge that is being sent to me will match well with a tonearm another fellow sent to me as an upgrade for my Micro Seiki BL-51.

The cartridge in question is a Shelter 201. According to the specs, it weighs 6.2-grams, and has a compliance of 15-10 @ 100hz. I figure that this means that it is around 26-10 @ 10hz.

The tonearm in question is a Micro Seiki MA-101 MKII, which is reputed to have an affective armtube mass of 7-grams. In addition, I found a wood headshell that weighs 7-grams as well. Should this not give me a total affective mass of around 12-grams?

Using the best compliance calculator that I can find online (korfaudio.com), it looks like a good match. The "old fashioned" calculator at Vinyl Engine say it isn't, but I have found it to be pretty inaccurate compared to my real-world findings so far.

How many of you have used this cartridge, and what tonearms and headshells have you successfully used with it?

Two matched pairs of 211 Psvane II
250 € /pair,
I can send pictures of the curves and valves.
They are in Spain.
Thanks
Esteban Bikic

Here i have for sale BURR BROWN OPA2228P Opamp, that is NOS, new, newer used. It is DIP8 package, have low input low noise 3 nV/sqrt Hz, Gain Bandwidth of 33 MHz and Slew Rate of 11 V/us.

It is excellent choice for audio preamplifier input stage, and it is made by well known manufacturer BURR BROWN.

Price is €60,00 (for 2 pair) + Shipping Cost and it is selling as 2pair only.



And have 2pcs NOS of ELNA SILMIC II 470uF/16V that is used for NFB capacitor in amplifier. This capacitor have best sonic so it used as NFB capacitor in amplifier.

Price is €6,00 (for 2 pcs) + Shipping Cost and it is selling as 2pcs only. I can do combine shipping.

Help needed, someone knowledgeable to building a power supply for my Mares Connoisseur phono preamp. My rebuilt 20 yr old power supply built by Ric Schulz went kaput, flamed out. Hoping to find someone here who might be able to build one or direct me to someone. After consulting with Ric, says he doesn’t do anymore such work. Thx.

Paul Wong
Located in the Monterey Bay area
559 240-1841 cell

Hello, I'm wondering, because I didn't saw much of this kind of speaker here. I mean compact speakers with a fullrange and a passive radiator. Is this something completelly off the charts ? Something not effective at all ?

Here are the two projects I made around this idea.


-Spherical enclosure made of blanda bowls (2.4L inside) ;
-Dayton Audio RS100-4 fullrange driver direct wired and no filter;
-Dayton Audio DSA115 Passive radiator.


-Pill shaped enclosure made of blanda bowls and layers of MDF (8.6L inside);
-Markaudio Alpair 11MS fullrange driver, direct wired and no filter;
-SB Acoustics SB15SFCR-00 5'' x 8'' passive radiator.

Thank you in advance for your replies on the subject.

I am in the process of selecting my mids drivers.
There are many products at comparable price: Scan Speak Illuminator and Revelator (why two?), SB Acoustics, Seas and Purify among others.
On what criteria will I choose the driver. It will be paired with same kind of price 6-7-8 inch woofer and a tweeter.
I look for detail and precision. One room 17 by 30 and the other 15 by 17 feet.
I listen to music lower than 90 dB and mostly under 80 dB.

Thanks for your help.

Selling a pair of Tamura F-7002 output transformers, in excellent condition

Prim: 3k5, 100ma
Sec: 4-8-16

Permalloy core

To say that these are pretty rare, is an understatement...

SOLD

What can be said about this design for Pluvia 7HD?

I've successfully developed circuits for my tweeters with three modes; 1, 2, and 3, as shown in the picture. I have a three-position switch with 4 pins. I'd like to use this switch as a selector for each mode of tweeters; mode 1/2/3 = position A/B/C, respectively. Please help me to create the signal path for them. Many thanks in advance

Hey guys I'm trying to repair a faulty KEF HTB2 subwoofer that happens to revolve around a 200ASC module from B&O.

The faults lie within the power supply section and during the initial failure a chain reaction of destruction occurred where several components failed. The problem here is that upon failing any markings that would otherwise identify said components ended up either charred black or in pieces.

I have scrounged the internet high and low for detailed images of the power section but haven't been able to find very much. A few images here and there, useful as a starting point, but not really enough.

The version that I've got is revision F.

Schematics for this are unobtanium, so if anyone could take some detailed pictures of the power section that would be most appreciated.

What I'm after are the resistor values for the components surrounding the main SMPS controller, I think this is an NPC1203D6, but that was from an image taken of a different revision. Resistor values for both the top side and bottom side are necessary as the destruction spread wide and far!

So far I've replaced the dead transistors, power MOSFET, controller, aux protection zeners and some resistors with what I could make out but no luck. The device fails to start-up and when the aux supply is provided externally it will start (and then continue working when the external supply is removed) but no regulation occurs.

minDSP SHD
Great condition.
$900.00 + shipping
I don't have original packaging, but will make certain it gets packed well.

Emotiva BasX MC1

BasX MC1 13.2 Channel Dolby Atmos® & DTS:X™ Cinema Processor​

Excellent condition.
$800.00 + shipping

Long-Time member, are there any other DIY members that are in Vancouver, Washington Hazel Dell area?

The use of two 8 ohm drivers wired in parallel is very common but why don't we see more speakers with two or more 4 ohm drivers wired in series?
It seems to me that would produce a far more tube amp friendly speaker.
For example we could use two 7 0r 8 inch 4 ohm drivers which are around 92 db sensitivity [like some of the Scanspeak Discovery drivers] to give around 95db sensitivity and an 8 ohm impedance.
Drivers like this for example.
https://www.google.com/url?sa=t&sou...4QFnoECBQQAQ&usg=AOvVaw0D3Rizpjdd3KJ5iPTysgum

I was looking at 7f7 tubes on eBay and came across some head scratchers of adapters. The obvious one is to use 7f7 instead of 6sl7. But how about 7f7 for 6sd7?

https://www.ebay.com/itm/387567242346

Pretty sure it is actually for a 7a7 and the seller made a typo in the title. But then I came across this one :

https://www.ebay.com/itm/205077894462

7f7 instead of 25z5? A 6v twin triode for a 25v double diode? It’s printed right in the adapter. The same seller is also selling a 7f7 to 25v6. What am I missing?

Does anyone know what the benefits / drawbacks of different relay contact compositions are, specifically gold over silver vs gold over silver palladium?

The context is a SPDT relay used for channel switching in the preamp of a Marshall head. The relay sits between between 12AX7 stages. The original part has gold over silver palladium contacts, but is impossible to find from Marshall or anywhere else (it was discontinued decades ago). What I have been able to find is a model from the same series identical in every specification except that it has gold over silver contacts.

A search online tells me that gold over silver palladium has better resistance to oxidation and sulfidation than gold over silver, but I have no idea if those are likely to be a practical issue in this application. I have no way to know if Marshall specified the contact composition for a reason or just used what was available.

It's appealing to use the one I've found since I know it will drop in to the amp mechanically and electronically without any adjustment whatsoever. If the composition difference is unlikely to make a practical difference then it saves finding a different relay which may require an adapter board or tweaks to the surrounding driver circuitry.

I bought these recently from you know where, and testing them with the PEAK Atlas DCA55, I got the following readings....

hFE: "23"... "58"... "103"... "108"........... so I decided to open the "23"....

Built and working perfectly, will build another and try some different things.
Solen 3.3uF MKP caps on output, 100R Holco H8 0.1% IV resistors.

SOLD



SOLD

Hello

I'm starting a new 3 way speaker project project after many years away from the soldering iron . My first project was a copy a famous french DIY 2 way project based on a foxtex fw208n and scanspeak tweeter. But after moving to a house with a much larger living room I felt the need a system room more capable of rendering the large ensembles and with stronger bass. And I also was bit tired of the somehow systematic sound of the bass reflex in the low register. That’s how I came to open baffle, but for some space reasons and went towards H frame design, and a thread on a French forum lead me to try a circular version of the H frame.

I have a background on acoustics from my studies but limited DIY experience so I’m looking forward to exchange with this community.

I'll post very soon some description of my project and crossover attempts in dedicated subforum

Cheers

Laurent

Having recently seen @tubelectron's micro and miniripole designs, it inspired me to play around with different variations to pair with my son's future bookshelf speakers, which are expected to be Zaph ZA5.2s (thanks for the midwoofers, @mordikai!) that could benefit from support below 80 Hz. I'm not looking for high SPL or shaking the whole house, but playing down (to ideally below 30 Hz) at modest volumes would be pretty sweet.

I'm swinging from cheap and cheerful to slightly better but still inexpensive drivers arranged in different ways. It seems that a downside is that it's hard to compete with a pair of inexpensive 12" drivers for one of these things. But, a fun form factor might make it worth not being the highest impact for the dollar. 🙂

I know very little about driver selection, so please take these ideas with a grain of salt!

Version 1: Quadripole... super cheap e.g. GRS 8SW-4 8" Poly Cone Subwoofer 4 Ohm drivers (currently $14 USD) arranged like a plus with 2 opposing pairs firing into a common chamber. The outer profile could be an octagon, perhaps with the "45 degree" sides curved inward a bit for visual cheekiness. Or maybe the outline is almost a pure circle. Not sure these would play that low with such high Fs drivers, though.

Version 2: Version 1 but with a better driver, e.g. GRS 8SW-4HE 8" High Excursion Subwoofer 4 Ohm. . Currently on sale for $40 USD. 10.5 mm xmax driver with 25 Hz Fs. Kind of expensive for a kid's ripole that still needs an amp, though, with 4 of them.

Versions 3 and 4: Trioripole... same notion as above, but with 3 drivers firing equilaterally into a common chamber. Could look pretty cute. Assumes an amp that's stable to 2 ohms or so, I'd imagine. Version 3 is cheap drivers, version 4 is the slightly better ones.

Version 5: fairly straightforward ripole using something like the GRS 8SW-4HE.

Version 6: fairly straightforward ripole using an inexpensive 12" driver like the GRS 12SW-4 12" Poly Cone Subwoofer 4 Ohm, currently 27 USD.

Thoughts? Other suggestions?

https://drive.google.com/drive/folders/11BpBLBlzvXQZEr_oiTbX5Bwy19xwU24E

This publication discusses :

1. Audio, Power Supply, Voltage Inverter, 5V to - 5V made with a few, unregulated MAX1680 IC's with a maximum output resistance of 0.6 Ohms. Discussed is MAX889, which is the similar, but, regulated.

2. + - 3.3V, Audio, Power Supply, Voltage Regulators, made with a voltage reference, amplifiers and TIP31 and TIP32 transistors. Many, other audio, voltage regulators have been discussed.

3. Based on the resources used for these, some ideas have been proposed for a power amplifier, which, is not the main subject of this publication and was introduced in the addendum.

Search the document or scroll down to the sections, named " Schematics " and Pictures.

As usually, mistakes are, always, possible with such a long document.

One pair of AD1862N-J DAC chips with a choice of board types. Either with Shift registers for Amanero or XMOS I2S modules or with JLSounds XMOS module on board.

Price is the same for both types. Perfectly built with quality components. Both boards come with AD797SQ op-amps installed - will include 82pF caps + 100R resistors for RC filter mod as shown in AD797 datasheet

JLsounds board comes with pin headers and connector blocks for I2S module.

Both DAC boards have pin headers installed for separate direct supply to op-amps.

JLSounds SOLD.

More to come... stay tuned folks

Does setting the DAC to Standalone mode reduce latency or have any performance benefits?
software mode there are more settings available, such as digital filters, but personally consider it irrelevant to change these settings.

I recently put together a nice phono stage pre-amp board. It is a VSPS. Anyway, I stuffed it into my source selector and wasn't happy with the crowding, and how I had to arrange the power (dual rail for the VSPS, single for the relays and dac board). So, now I have decided to put the VSPS board in it's own chassis, and I am going to include the power supply.

My question is, how much shielding or distance between the transformer and the pre-amp board is needed to be more or less hum free? The chassis is 10x6x2 inches. I will have the IEC power and transformer (50VA +- 12VDC) on the left, and the board on the right. About 4-5 inches separation. The chassis is steel. What additional shielding if any should I expect to need to keep hum to a minimum?

Thanks in advance,
Roger

I just received my new to me amp. I opened it up for a visual inspection before plugging in to the wall. I notice there is no ground on the IEC receptacle. There is also n empty ring connector on the star ground. Did these units come like that from the factory? I know my Denon receiver has a 2 prong IEC receptacle, so not sure if I need to connect a ground to the amp. I assume that the ground is lifted to reduce hum.

Hello, somebody can help a newbie to find some equivalent/replacement Transistors for my old Technics SA-5200 receiver? I Would appreciate very much your guys help to bring this guy back to life.
Each transistor is marked in the schematics image, and their role in the circuit is also marked on the parts list image below.
Thank you all !!!

TR 705, 706, 709, 710 -> 2SC1318R , Q

TR 110, 707, 708 -> 2SC828Q , R

TR 711, 712 -> 2SA720R , Q

TR 713, 714, 715, 716 -> 2SD318Q , P

For sale tubes that I dont need anymore!!
1 x JJ 5y3S totaly new
1 x JJ ECC832 totaly new
2 x Tungsram ECC82 pair- SOLD !!!
Buyed by Tube depot Usa
2 x 6x5gt CV574 Brimar Nos
Buyed by Langrex UK
2 x 6x5gt Sylvania Nos
Buyed by Tube depot Usa
All together 100 eu plus 7,90 euro tracked shipping inside EU.
For the buyer I will put some new and used tube socket in the package.
Payment by Paypal Friends.
For more info cantact me.

Fellow diy'ers, the time has come.

Shipping is limited to small items only.

Selling the house, so must clear out 30 years worth of the world's best hobby.
Some large, some small, some short, some tall.

Bring your friends, for a spending spree,
Some are expensive, but some are free.

Commercial speakers, bare wood hobby types, and lots of raw drivers. Some NOS, some just old.
This is not my retirement fund so you will be pleased with the prices, except of course with the expensive stuff.
Come rummage around, way too much to dig through and try to list it. Not all items are displayed in the photos.

Altec Lansing, Dynaco, Advent, Paisley, Sony, Selenium, CSS, Realistic, Cerwin Vega, Dahlquist, Community, JVC, HiVi, Motorola, Foster, Polk, Sammi, Airborne, Koss, Mission and Sharp are the ones I remember off the top of my head.

Includes:
Dust, at no extra charge.
Partial proceeds will be donated back to diyAudio. Amount depends on how much support this gets.

I'm selling an old Rythmik Audio A300SE DirectServo subwoofer plate amplifier.
According to previous owner the amplifier is not working. I got this when I bought a 12" Rythmik driver.
I have no way to test this and therefore do not know what is the problem. But based on the capacitor brand alone those would be my best guess.
Date code seems to be from 2008.
Should be fixable.

Price 30€+shipping

* 14. März 1933 in Chicago, Illinois; † 3. November 2024 in Los Angeles, Kalifornien



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...and 120WPC into 4 Ohms.. Stereophile's John Atkinson measured one and got maximums of 150 Watts into 8 Ohms at 1% THD, 240 into 4, and 380 into 2. VERY impressive!

My question--are those large outputs achieved with the amp still in Class-A biasing or does the amp fall into class-AB biasing beyond, say, 60 Watts into 8?

Here's my system recently.. Amps are PS Audio BHK600s and Pass X260.8s; speakers are SoundLab Majestic 745s.

Hello Community,

I hope this message finds you all in good health and high spirits. I'm reaching out to this knowledgeable forum with a humble request for assistance that holds significant importance to me.

I recently registered here, driven by my passion for electronics and music, to embark on a project that's close to my heart: crafting my very own audio amplifier. This journey has been incredibly rewarding so far, but I've reached a point where I could use a helping hand from experienced minds who understand the intricate world of electronics design and PCB layout.

I must admit that the learning curve has posed some challenges, and my autistic traits have added a layer of complexity to this process. I have always hesitated to share my personal journey, as I've encountered instances where discussing my condition led to misunderstanding or undesired pity. But today, I've decided to reach out because I believe there might be individuals here who can empathize with my journey.

This journey has brought me to the "Apex AX11", a project that struck a deep chord within me due to its intentional omission of a variable resistor and its unique approach to grounding. However, despite my enthusiasm, I've encountered challenges that have left me feeling somewhat stuck. While it's conceivable that the creator of this schematic may be a member of this forum, I remain uncertain about his current level of activity.

In essence, I'm hoping to connect with someone who understands the complexities of dealing with both electronics and autism. Any support and guidance, no matter how small, would be immeasurably valuable to me.

I've dedicated time to studying schematics and electronics, often navigating the journey alone. The process can be incredibly frustrating, especially when the path forward isn't clear. This is where I now find myself, seeking to navigate the realm of components selection, schematics and PCB layout.

I discovered EasyEDA, a software that breathed new life into my project by offering ready-made component designs. However, my struggle now centers on translating my schematic into a coherent PCB layout. I find that as I move components around, lines appear to shift connections unpredictably. While I understand that components ultimately interconnect, this uncertainty leaves me concerned that I might unintentionally make errors.

In short, I'm reaching out for assistance. Opening up and seeking help is challenging for me, but my intuition tells me that the incredible minds of this forum might hold the solutions I seek. This project means the world to me, and I believe that the understanding and knowledge within this community can help me overcome these obstacles.

To provide some context about the project, I've made a few component substitutions:

BC546 to BC546ABU
MPSA92 to KSP92BU
BD249C to TIP35C
BD250C to TIP36C

MPSA13 - Did not find a candidate

I'm seeking your valuable input on whether these component swaps are suitable for the audio amplifier design. Additionally, do you recommend any adjustments to resistor and capacitor values to ensure compatibility and optimal performance?

I've also noticed a particular detail within the schematic that has prompted a query. In regard to the speaker (-) input, I've observed an arrow denoted as GND. Could you kindly provide clarification regarding whether the speaker (-) input should be linked to this designated GND arrow? Furthermore, I'm inquisitive about whether the ground stemming from the input should be connected to the left-ground point. Alternatively, is the GND originating from the power supply intended to be connected to the GND point on the right side? Additionally, should both the (+) and (-) speaker inputs be connected to the Output?

I extend my deepest gratitude in advance for any insights, guidance, or assistance you might offer. Your willingness to help me on this journey is a gesture that I deeply appreciate.

Thank you for taking the time to read my message. Your kindness and expertise mean more than words can express.

Warm regards,
Prognosis

Thanks for allowing me to be part of this group. I look forward to being able to engage with the other members.

Hello everyone

Kosie here. I am firmly in my middle age and geek out on all things gadgety. I have been working with computers for more than thirty years. Came across the site researching building the next level after wanting to upgrade my pi/hifiberry streamer and wanting to create the absolute best (within reason) listening experience while working on the PC. Binge watching Gabster on YouTube. Obsessing 🙂

Need.to figure it out.

Bye

Hi all, now being part of this i look forward to learning a lot more.

I am interested in DIY speakers as well as upgrading one of my current speakers crossover.

Hello everyone, 🙂 My name is Tony, I listen to a bit of all musical styles but I'm more and more attracted to classical music over time 😉

?? - I'd imagine Scottmoose's 18 liter reflex would be a good starting point for overall size - a damped stub at the top of the front chamber might be needed.

Dear @DonVK and @fluid ,

I’am trying to design a diffraction horn for use with a B&C DCX50 compression driver. I’ve read yuichi arai’s book about diffraction horn design and build a CAD model. Now im interested if I can further optimize the design. I’ve tried to simulate the horn in Akabak but I came by the problems you describe in your blog post:

„Especially the individual fins or separate channels and their integration as BEM model at throat and at the end of the fins is tricky. You could either simulate them as individual channels but in this case several interfaces are necessary and you could end up with interface issues (one to many and many to one subdomain). Or the BEM model is one single mesh including the fins but then at fin start and end you encounter very close vertices when the fins are very sharp which is a problem with BEM.“ -> https://sphericalhorns.net/2023/04/09/the-mk3b2-radial-fin-horn/

With the individual channels as separate domains I not only struggle with interface issues, importing the model into akabak is incredible tedious. With all in one domain the fin ends are getting displayed in purple, indicating that the mesh is not sufficient dense.

Which of the modeling options yielded you the best results? What were your mesh settings? Did you use Gmesh for meshing?

For non-fin-horns i found this mesh settings:
"For examples a 400Hz horn simulated up to 10Khz, needs the driver membrane meshed at 5mm (150 elements), the inner horn at 10mm (2800 elements), outer horn at 30mm (1000 elements) mouth interface at 10mm (1000 elements), and edge at 20mm (100 elements). This 5050 element model, with 64 frequencies on an 8 thread 3.5Ghz processor takes approx. 3-4 hrs to solve." ->https://sphericalhorns.net/2019/10/20/bem-simulation-for-a-freestanding-horn/

How did you model the exterior of the horn? As the horn mouth is not straight I placed the horn inside an infinite baffle and modeled the outside of the quarter horn.

Hp3314a function generator front panel display not working. So i checked the rail voltages. I hv when all other boards are unplugged +15 -15 +5 volts rails showing correct voltages across the cap on +24 v rail i hv +31 volts and across the cap on -24v rail -32 volts and the led comes on on the board. However when plugging in the other boards the voltages drop and the led does not light also no readout on the front panel the voltages show +15v = 11 v -15v = -1 v +5v = 0.5 v across cap on -24v rail = 0 v and across cap on +25v rail = +30 volts… could you help where i need to check whats causing this please

how do i find a way to e-mail a member? (yes, this is an eedjit question for a variety of possible reasons.) thank you for your help- anyone?

Hello

Relative newbie here.

I'm rehabbing a Sony TA-F444ES II, replacing the fusible resistors and electrolytic caps. The PS filter caps are Nichicon Great Supply, 12000uF, 63V, squat in form factor: 2" (about 51mm) L x 2.5" (about 63mm) diameter. They were mounted to the board with beefy solder tabs spaced at 16mm c-c. Getting them off was not easy, but I digress.

So far I have not found a replacement cap with fits well in the case and has solder tabs with the correct spacing. The closest I've found is the Nichicon KZ series, LKG1J153MKNF in particular - 40mm diameter x 68mm long/tall, which might be too tall for the case. At least the padding on the underside of the top surface of the case would need removal.

The KEMET ALT22 series are close, but have tab spacing of 10mm, which is probably too narrow.

Both the Nichicon KG and the specific KEMET ALT22 seem unobtainable - None of the big houses have them, the regional reps ignore my calls, and KEMET HQ ignore me as well.

The current plan is to solder copper tabs onto the snap-in pins of Nichicon replacements, then additionally mount / support the caps with (nylon) standoffs glued to the cap case and passing through the existing cap vent holes in the board. The caps I've chosen (still 12000uF) are physically much smaller.

I realize this question comes up a lot, but I have not yet found a better answer. Thoughts? Thanks. Tim

Looking for a replacement speaker for the Altec Lansing ACS 45.1 satellite. It is a 4 ohm 3" speaker. I don't know the max power it is spec'd at but the speaker is the A2156. Any help finding a source would be greatly appreciated.

Hi All,
I need a reality check. I came up with an idea of using some spare parts to build a variable DC power supply. I will power the unit with my variac. The bridge rectifier is from Sjöström audio. The filter cap array is from here. The caps are rated for 100v, I will stay well below the 100v. My question, do I have to ground the star ground to the chassis? I will only output v+ and v- to test my boards and the broken power amps I am working on.

Hello everyone, I am writing to you from France, sorry in advance if my English is not always correct.

I am a proud owner of a Velodyne SPL15 RCHE since 10 years but unfortunately it broke down recently, there is no informations or nothing on troubleshooting these devices on the French forums.
My subwoofer turns on electrically but I have more bass, I made a small video, posted on Youtube, to hear the phenomenon (a kind of breathlessness).

Youtube link : Login to view embedded media


I disassembled the subwoofer, on the board (inside the metal cage), I detect a small “burnt” area, I would like to repair it if possible, by replacing some components,

I'm going to change :
the 4 transistors named A on the picture
+
2 transistors named B
+
2 diodes named C
+
1 resistor 470 ohms named D
+
1 resistor 220 ohms named E
+
1 diode pin named F
+
1 diod CMS named G

however, I don't have the electronic wiring diagram, not found on internet, if someone has that, I'm glad to take it, thanks in advance.



thank you for your help.

I recently bought one on ebay. It has the tda1541a chip and sounds pretty good. I think it has some potential just wondering if anyone has gone down this road.

I'm pulling old-but-good audio stuff out of storage to set up a TV/music area in the family/living room. I'd like some advice about how to connect the audio stuff. Weirdly enough, the main issue is how to control the overall gain (volume). I want a system which is simple enough that family members, including my 80+ mother in law, can use it without help from me.

The output side is ACI Sub1 + Sapphire Two loudspeakers and a Parasound HCA1200 amp. The input to the amp is RCA analog L/R line level. The amp has a front panel gain control, but I'd prefer not to use that if possible.

The audio sources are:

CD: Sony CDP C79ES, ouputs are RCA L/R analog + Toslink Has front panel and remote volume control (motorized potentiometer).

Bluetooth: 1Mii interface for streaing devicesL has RCA L/R analog line level outputs

Audio/Video sources:
Sony PS4: used for games, streaming movies, DVDs, outputs are HDMI + Toslink

Sky satellite box: outputs are HDMI + Toslink + RCA L/R analog

The last two devices are connected to a LG 60PV250 TV via HDMI. The TV also has a cable input which we use, but tne ONLY audio output is
Toslink (fixed volume!).

My current plan: an inexpensive relay switch that has three pairs of L/R RCA analog inputs and one L/R RCA analog output. The relay switch output goes to the amplifier. Input 1 comes from the CD player, Input 2 comes from the Bluetooth interface, and input 3 is going to come from the TV set.

When listening to the CD player, we'll use its remote and volume control. When streaming bluetooth we'll use the app's volume control. When watching TV/Video the TV remote will do the volume control.

I had hoped to connect the TV to the audio system via a Toslink->Analog converter. Problem is, if I do this then there is no way to control the volume, the TV remote won't do that.

Easiest solution is (I think) to open up the TV set, and wire a DPDT switch to turn off the internal loudspeakers and redirect their output to a voltage divider followed by a pair of analog RCA L/R output jacks. My only concern here, I don't know if the frequency response of the built in audio amp has been shaped to match/compensate for the inbuilt speakers. (And no, there is sadly no headphone jack I can use to get line outputs!).

Is there another simple approach? I don't want to introduce yet another remote control into the pile, and it seems to me that since my family is used to contolling the volume of the Sky satellite box, the PS4 and the cable TV via the TV remote, keeping it working like that is the best solution.

Thanks for any advice or other solutions!

Bruce

A stepwise volume control is implemented with a set of tiny relays and resistors. In a high-end audio system, a noticable sound improvement over potentiomeneters is obtained, also compared to 'audio grade' potentiometers. Its IR remote control provides convenience over solutions with stepped attenuator rotary switches. The sealed relays will maintain contact quality over a practically endless lifetime. The design represents a audio 'preamplifier' of top-class sonic quality, in a compact and affordable implementation.
The design uses high quality Fujitsu FTR-B4CB4.5Z bistable relays, as well as mil-grade audio grade resistors RN55D, RLR07, CMF55 from Vishay-Dale, which have an excellent reputation in the audio field. The circuit is designed for high-quality audio applications.
The input impedance is constant.
The 1.5 dB adjustment step covers a sound attenuation range of 94.7 dB, 63 steps. By eliminating any active electronics, a very clear and open sound is maintained. There are no clicks when adjusting the volume in the speakers. Encoder for control from the panel.
The IR receiver allows remote control. When the power is turned off, the last volume position is remembered.
The circuit operates from a stabilized voltage source of 5 V.

I'm building a TPA3251 based board with 3 outputs (1xBTL + 2xSE) and I'm not sure if I designed the input correctly. I followed the EVM documentation but I would like a second opinion.

2.2 BTL MODE (Three-Speaker Output)
OUTC and OUTD are the SE output channels and OUTA and OUTB are the BTL channels for 2.1operations. OUTC and OUTD can only be in DIFF input mode.

Schematic of the EVM module:



My design:

I am looking for a schematic or service-manual of a Musical Paradise MP-701 preamp. Can anybody help me?

Hello, I have been on this site for a while, but this is my first post. I bought a wonderfully sounding Music Reference RM-9. I would like it to continue working optimally for years to come. It is possible to get more boards made for it. Member A1008 used to make them. If you are still here, please advise if you are able to make more.
Cheers, Soren

How to run rca's to 4 channel bridged . I ran one set off front left and one set off front right with splitters. Landed left rca's to 1 and 2 and right rca to 3 and 4 believe that is correct . Now my amp Memphis sixfive 400.4 has a 2ch / 4ch. I'm I still in your channel since I used all four inputs or 2 channel since bridged . Oh and hu pioneer 4400 has a output switch that says that or subwoofer .technically not useing rears and subs are on there own rca's. But I have to choose one .