Just acquired a single one of these - don't suppose anyone knows of another one that can make up the pair?

Hi guys ,
The source selector switch on my Rata amp is looking quite fragile and I did discover some small bits of plastic beneath it so I think it’s on its last legs .
I don’t really want to risk removing in order to identify it for obvious reasons so I’m hoping someone may recognise it ?

The amp is from the 1990’s .

Hi guys,


I am working on Sony v-fet gear for about 15 years as hobby. Mainly cleaning overhauling and readjusting them. I have worked on at least 50 Sony TA-4650 in that period and saved many of them from becoming just a big and lumpy paper weight.

And one issue is still hard to solve; popping speakers when turning off the amp. Renewing the relay and capacitors is standard procedure, since the old ones are unreliable. Checking all the transistors and when needed, changing the transistors and resistors aswell. Still sometimes it is impossible to not have this annoying pop in the speakers. Yes I do check all the parts in the speaker protection circuit.

And yes I am also aware of the later changes in the circuit advised by Sony.

Anyone an idea how to solve this annoying issue ?

I purchased this thinking it is a multi channel amp, but it is a multi room amp. I don't have all the cables and connectors to test the amp with so am selling as spares/repairs.
I purchased it as a fully working amp, and am pretty sure it is working fine, but am unable to prove it



£15 or ONO. Pick up from west yorkshire

Hello,

Looking for RAAL tweets, preferably 70-20XR

Let me know what you have

M

Several components for hifi/home audio in used condition are danger even outside of operation, because the integrated capacitors in the mains inlet C14 plugs are not disconnect from mains after switch off the component (and not to check and for replace).
Therefore the aging is more extend and it is not possible to check the condition like describe under
because the parts are potted and thus not accessible without destroy.

A friend of me observe such IEC C14 inlet versions with internal burning parts in his Linn Pre-amp KAIRN and Linn CD Player KARIK (unfortunately covered in a black shrink) exact according the description under this URL's:
https://www.vintage-radio.net/forum/showthread.php?t=88137
https://www.vintage-radio.net/forum/showthread.php?t=82160
https://www.vintage-radio.net/forum/showthread.php?t=69128
His apartment smelled extremely unpleasant despite ventilation for many days after this event.
Are the problems in this mentioned threads extremely rare ?

Because there is no access for replace the bad X2 capacitor - go to
Login to view embedded media only the possibility for whole replacing exist of course with the risk of the same issue after a certainly period of use (because all parts are always connected to the mains even after switching off the main switch).

Thank you for comments.

P.S.: In general I strongly recommend always to replace by a passive inlet (i. e. without integrated RFI parts) according the attached images No. 8-10
Additional an external RFI unit resp. mains filter according those under
https://www.audiomisc.co.uk/mains/filters1.html
or according the attached images No 11-16
but connected behind and not before the mains on/off switch.

This threads don't provide the wanted information:

Hi,

Not sure if this is the right place, but I'm looking to sell a pair of RAAL 64-10 OEM flat foil ribbon tweeters. I'm located in Phoenix, AZ, US. Willing to ship @ $300 inclusive of shipping. Will add pictures soon or DM me. Thank you.

Hi all. Searched and didn't see anything on this. Working on a DC power supply for tattoo work. Most I see are compact, and switching. VR, and some also offer CC and/or CV. I also saw some list frequency, but when I investigated, it's the needle frequency that you get with whatever V and I points the motor currently has. But that got me thinking...

What effects could be useful? And how to actually use tube(s) (not just decoration)?

Rectifying 18V@1.5a secondary? Nope. A triode as a pass element, maybe. What if...I use a CC/CV adjustable regulator to get my 20v B+, I could then burn some of the available current through a simple oscillator and load resistor. Say the reg output is 10v@1a. If I had an oscillator, variable from say 20-200hz, burning 400ma, then I'd have a DC voltage with variable frequency power ranging from 600ma-1A left available, for the gun coil in parallel with it.

So I looked for simple triode oscillators. I found this, but no formula. Most everything else was RF related, and certainly nothing below 500hz. If anyone could point to low frequency oscillator circuits, or just the basic math of it, it would be greatly appreciated. I saw that one of the oscillator types (Hartley?) use diodes even.

Thanks much all, this is a fun idea so far-
Loren

Bought a preamp board from Aliexpress along with transformer. When I hooked it up the transformer got very hot, so I disconnected it. Am I getting something wrong here or is the transformer defective? See pic of transformer. I hooked up the Green and Black wires as indicated to power .

With the success of my last design, a 3-way in the “classic” format (https://www.diyaudio.com/forums/multi-way/365119-soreta-3-classic-monacor-dayton-audio.html#post6493033), I started to think that I could replicate such a design with inexpensive but good performance drivers. The main problem with this statement is the availability of an inexpensive 8” driver with good bass performance and with low volume requirement. However my dreams came true with the availability of the PFC family of drivers from SB Acoustics, and specifically when SBA made them available also with a round frame.

I have yet to test the drivers but I have settled on the SB20PFCR30-8 for the bass. It should work reasonably well in my intended cab, even if some more volume would be preferred.
For the mid I was undecided for some time, and my first choice was the SB13PFCR25-4. But when drawing a sketch of the cab, I realized that in order to lay reasonably the drivers on the baffle and to make the mid enclosure not interfere with the bass I’d have needed to make a taller baffle than what I was thinking of. So I bought the 4” SB12PFCR25-4 instead, on the datasheet it appears to be sensitive just enough to mate well with the woofer.
The chosen tweeter is the SB26STCN-C000-4, I know that some other not expensive SBA tweeters have a small bit better performance, but for this application I prefer a small faceplate tweeter, and this forced my decision. And this tweeter should sustain well a planned 2.5 KHz crossover point.
In any case cost for the drivers for both speakers was around 170 Euro, and this fully qualify the SB(acoustics)INEX(pensive) name. Let we see what comes with the crossover.

Ralf

I'm a hard-core DIY builder. And by hard-core, I mean completely bonkers... 😀 😀 😀

For approx. the last 4yr I've been making build guides (here at diyaudio.com and elsewhere) for people interested in these projects. I've found that most interested parties can get one of these done with a bit of patience, guidance and a decent set of photos. So I've been doing that. It's a blast, and I've had the honor of taking to people (Email, phone, skype) all over the world about their projects and our hobby.



Most of these guides are Nelson Pass designs, but I will tell you that there is a reason his projects are so incredibly popular. Take a look -

Pass/Firstwatt F5 (My first big guide, and this is still the most popular project in DIY land) An illustrated guide to building an F5

The B1 preamp, this post got re-formatted and kinda screwed up, but still not bad. B1 preamp build thread

The incredible Pearl 2 phonostage - Building a Pearl 2

The F5Turbo amp (this one looks very clean, I'm quite happy with it) - F5Turbo Illustrated Build Guide

The legendary Aleph J amp, (what I've been listening to for quite some time) -- http://www.diyaudio.com/forums/pass-labs/241729-aleph-j-illustrated-build-guide.html

The Pass "Amp Camp Amp", this amplifier and guide is intended for the complete beginner, and so shows essentially everything -- ACA illustrated build guide

The Pass Burning Amp BA-3, this one has a video I really like in post #3 -- BA-3 Amplifier illustrated build guide

The front-end board from the BA-3 is a fantastic preamp, and currently in use in my system, here -- http://www.diyaudio.com/forums/pass-labs/258022-ba-3-preamp-build-guide.html#post3968063

The Pass F4, this is amongst my most favorite guides -- A guide to building the Pass F4 amplifier.

The wonderful Amp Camp Amp v1.0 ACA illustrated build guide

The F6 amplifier F6 Illustrated Build Guide

And a few non-Pass projects;

The O2 headphone amplifier -- Building the O2 Headphone Amp

Hagerman Bugle 2 phonostage - http://www.diyaudio.com/forums/analogue-source/237627-hagerman-bugle-2-a.html#post3605491


SL-1200 DC PSU -- SL-1200 DC Power Supply DIY

SL-1200 tonearm rewire -- Rewiring SL-1200 Tonearm

A guide to the universal chassis from the diyAudio store - http://www.diyaudio.com/forums/parts/245959-illustrated-guide-4u-deluxe-chassis.html#post3704810

And the universal PSU guide - diyAudio Power Supply Circuit Board v3 illustrated build guide


Gawd, that's a lot of things when listed like that. 🙂 I've never actually made a list as such. (And I haven't gotten any of my Valve project guides completed...)


My apologies, now that your eyes are bugged out from looking at all that, I suppose you would like to know a bit more about me... Here's everything you need to know about me in regards to DIY projects, a (literally) 5-min talk at Burning Amp Fest '13 -- https://www.youtube.com/watch?v=V5eOnuQJ3ww

Hi,

I am modeling with VituixCAD some 2.5 speaker. I do have couple of woofer measurements at hand, but the simulation shows that the low end of bassreflex box will be exactly the same if I put 2 woofers lets say in 10L box tuned to 60Hz or separate them into 2 x 5L chambers tuned to 60Hz. The only difference is 2 vents are mandatory then.

Somehow my guts feel that separate chambers will have better isolation of lower woofer diaphragm from mid freq inner bounces of upper woofer and lower overall acoustic crosstalk between them. But on the other side somehow have a feeling that bigger single box has some advantages... But cannot name them. 😀 Maybe none?

So, what would be your choice in every choice?
1. Two separate chambers or single?
2. In case of single chamber and single vent - the best position is probably in the same distance to each woofer? Does it matter?
3. In case of 2 chambers or single chamber with two vents - do they need to be tuned a little different not to have the same resonance?
4. In case of 2 vents - do they need to be in identical position to their relative woofer? If the distance of the vent exit from woofer cone is 5-10cm different between each woofer-vent pair - it can be measured, but can it be heard with ears?

Opinions and facts are welcome. Thank you!

Hello everyone. I've been interested in audio for quite a few years now and made a few DIY projects already. I found out about hornresp later learning about this forum. The hornresp app is extremely useful and full of features. I want to learn more about it and share my thoughts on different audio projects with other people here. I'm excited to become the part of the community.

1970 Pioneers from Japan. SA500 13watt. State of the art silicon transistors! Use it Everyday.

I'm Paul.
Living in Scotland.
As my hobby I'm repairing vintage audio, modern as well but not greatest fan of the smd 😀
I got some experience but like everyone sometimes I need some help as well.
All the best for everyone.

GRS12PT - sealed box on top with old Beta8CX/APT50/APT3 - series network 3mH/30uF from tapped pipe to 8CX woofer - 0.47mH on 8cx woof - 3.3uF.0.3mH on APT50 - some series attenuation w. some C bypass on CD.

Source = Flamma Drum/Loop mini pedal /Fosi TPA3255 mono amp.

Don't know what forum it fits ;^)


Login to view embedded media

This is the test result of 2SC2088 and 2SC2240
The distinct differences between these transistors happens near the low end switching point where 2SC2088 tends to by hyper sensitive.

HK870 Amplifier section may have blown outputs or blows fuse!
This is the case of a customer complaint ...
These days outputs are scarce and when available, they come at a premium price. Do I want to take a chance blowing or shorting my new transistors just by replacing them and see what happens?? No!
Since mid 1980's my instruction to my technicians have always been, make sure the amplifier driver stage all the way to its input stage (differential is any) is working good without installing output transistors. That understanding among the early days technicians and service engineers still holds true, just as anyone here agrees that the first order of business in any electronics repair is to make sure all essential power supplies are working properly.
In order to verify and troubleshoot the HK870 amplifier section, one needs to take some simple step. Here it is!
If you have any suggestion, I would like to hear it.

My sony TV is having an audio problem it shows a constant fast blinking green LED.
I have removed all the peripheral equipment and pulled the HDMI’s
Removed the smartcard
Powered down the TV for 3 minutes
Reapplied main power
Picture and flashing green led IMMEDIATELY return, normal video available
Sound adjust bar visible on screen in position Min
Increased the soundlevel using remote, audio is heard but as soon as remote sound button is released the volume automatically slows to MIN again
This is repeatable

Hold TV power OFF on remote for 5 seconds, TV turns off, RED LED is ON, GREEN LED is now off.
Turn TV back on using remote,
Reported problem appears again.

Any suggestions?
The problem started after watching Apple TV PHOTO’ via HDMI and having the Apple TV sound in MUTE

Hello all,
Returning member. Haven't posted here in probably 10 years. Looking forward to coming back. Many questions I have about audio as I continue to improve my system; many decades in the making now.
Some background information:
Have been an electronics hobbyist since I was 5 years old. Main interest is in amplifier designs and speaker building, and I have built many examples of both throughout the years.
Professionally, I have been working in the semiconductor industry for 27 years now, first as a test engineer, then as a validation engineer, and most recently as an analog designer.

Hi... I'm hoping I'll get some real advice on recapping 3 sets of speakers. I normally research topics pretty thoroughly... but this has been crazy!

Looking forward to your suggestions

Jonathan

Hi guy's ,

Has anyone did the mod ?

.

I know that it is not the best solution to use THT components in the case of TPA6120... 🤓
Any advice?

I have 2 Eminence Delta 10A - 10" drivers available. There were originally used in the 7Pi mid horn from Pi Speakers. I have moved to a different driver so these aren't needed. $120 for the pair. Free shipping to US lower 48 states only.

For sale:

• Remix capacitor 0,1uf 400v - 40$ / 100pcs new
• Remix capacitor 0.1uf 600v 50$/ 100pcs new
  
  
  
  
  
  
  
• Western Electric D-168574 16uf 120VAC $ 400VDC - 1000$/ pair
• Western Electric 4600uf 30v - 90$/ pair
• Audio Prosessor Super Linear 47uf 600v NOS 270$/ pair
• Vfet Tokin THF 51 used 70$/ 2pcs matched pair

Hi there,
because i´ve lost track of ACA, i want to ask if someone would be so kind to help me find BOM/parts-list for 1.6/8.
Already got Boards and Cabinets and want to finish them before x-mas.
This thread is huge ...

Hi! I have traced the Naim NA322/4 MM phono board PCB layout from some photos that I found online. I didn’t find any schematic, but there were enough pictures and some descriptions so that I could identify the parts.

Anyway I have some questions left:

1. Can anybody tell me if I have identified the transistors correctly? I am not absolutely sure which of the 10 transistors are ZTX384 and which are ZTX214.
It was hard to tell this from the pictures. Unfortunately I don’t understand the circuit enough and don’t have enough background knowledge to really be able to figure this out logically.

2. Is the polarity of the tantalum caps correct?

3. I can use BC560 instead of ZTX214 and BC550 instead of ZTX384, right?

4. Do the transistors have to be matched? And which have to be matched?

Thanks so much in advance!

Hi folks,

I have been searching for an answer to the following question:

What is the purpose of a cathode bypass capacitor in a White Cathode Follower buffer?

My rather limited understanding of tube-land would indicate that a cathode bypass capacitor is employed when the is a need for gain augmentation and/or output impedance reduction.

If I remove the cathode bypass capacitor in the following circuit, would I need to pay attention to any other component values?



My goal is to mostly drive low impedance cans.
Specifically, a 38Ω load (Sivga Luan pair of headphones).
My higher impedance cans will be driven by my other amps, so I don't really need for this Morgan Jones mini-tube headphone amplifier to be compatible with cans above 60Ω.
------------

Anyway, back to the original questions:

A. If I remove C3 completely, do I need to consider altering any other values in the circuit in order to not upset the balance of the WFC?
B. What's the 'mystery magic' of having a cathode bypass capacitor in what's essentially a unity gain buffer?

With respect,
Nick.

Hello, first time posting. I am looking for a review of my car audio wiring without a head unit, any help is appreciated,

• Streamer: WiiM Mini
• DAC: Schiit Modi+
• DSP: PRV 2.8x
• 4 Channel Amp: Morel MPS 4.400
• Mono Amp; JBL A600
• Fuse Block: amazon link

Motivation: I will be using a WiiM Mini to AirPlay 2 music from my iphone, this connects to my Schiit Modi+ DAC via optical. This is why I have the 2 12v-5v buck converters to power those via USB. DAC->DSP and then to both amps pretty standard from there.

My battery is in my trunk so all runs will be less than 5 feet.

Thanks!

Hi everyone,

I’m new here and looking to learn more about vacuum tubes. They’ve always intrigued me, and I’d like to understand how they work, what makes them unique in audio gear, and maybe how to better sort my small collection.

I don’t have much experience with them yet, so I’m here to read, ask questions, and hopefully pick up some knowledge from the experts.

Thanks for having me!

Hello!

I am building the SBA 941's from Troels Gravesen and I have a few questions regarding the cabinet construction which there seems to be very little guidance available.

I will be using a CNC machine at my local makerspace for the MDF cutouts and I have therefore made the entire cabinet in Fusion 360. I believe Troels mentioned somewhere that the cabinet construction could be improved. Therefore I have taken inspiration from here and have added another panel inside the cabinet to make the back panel removable for any future adjustments that may need to be made. The panels inside the cabinets also have 5mm deep tracks for extra rigidity and to make the gluing process easier.

The middle panel however seems to have some weaknesses and I suspect that the schematics call for the removal of too much wood which may weaken the internal structure, see the photo provided with the black arrows on the right side:



Should I make the 130 mm diameter holes smaller, and if so do you have any tips on which size would be optimal - perhaps 105-115mm? The current holes seem to be to close together and the wood in between them gets very thin which I presume may be a bad thing

My other question is that I'm not sure how the front panels should be attached to the rest of the cabinet? Preferably I would like some form of mechanical solution alongside the glue that is to be put in place.

I have added a few other images of the cabinet construction in Fusion 360, hopefully this will give you a better understanding of the cabinet structure - the only part missing is the horizontal piece linking the back panel to the middle panel which I have not added yet. I am open to any changes and improvements that can be made in order to reduce cabinet resonance. I already have quite good cabinet dampening which I hear might be as important as a good cabinet structure, however it would also be nice to have a solid cabinet.

I appreciate any help that you are willing to give, this is my first ever speaker build so I duly apologize if I have made any severe mistakes - I would appreciate if they could be pointed out if so. Thank you in advance and have a nice day!

Link to the official website here: http://www.troelsgravesen.dk/SBA-941.htm

Does anyone know the manufacturer of these drivers?

Anyone has TSP parameters of these "DJ" loudspeakers?

These drivers are spare parts for portable bluetooth loudspeakers.

And are sold from 6 inch up to 12 inch size.

Looking around on various sites : Why is it so hard to find small (so low voltage) MKP (polypropylene) capacitors for audio ?
There are : AC/puls , DC link , motor run, power factor correction, RC snubber, RF and power , RF microwave, suppression film capacitors and... general use .
Which are for audio , in the 4,7 uF to 10 uF range ? ( for input of amps , not for speaker filters)
Sure I can find these Wima red ones and those grey Kemet, but often only for high voltages which makes them very bulky.

Привет всем!
Ребята, мне нужна схема платы Midiworx ADAU1467.

H I am masadajunglist and i
i am a audio hobbyist building speakers and specializing in battery operated ones. I am here to ask some questions about my own audio projects and I hope I find like minded people to discuss all things audio here!

Obviously new here. Retired a few years back and getting back into my hobby of electronics, amp/preamp rebuilding, etc. Hoping to learn and share as I jump into this feet first.

Hi everyone,

I'm a software developer with a deep interest in audio and DIY. I’ve been a long-time lurker and have learned quite a bit here over the years. I’m finally ready to share my own DIY speaker designs.

Thanks!

I built a TriAmp 5 years ago using class a/b amps and the performance is very good. It has an active filter in the signal input.
I ended up with 28 earth points and I am sure this is why there is no hum.
I am now considering building a TriAmp class D and I am after advice on whether there is a benefit over a single amp as there is using class a/b amps.
I have not built any class D amps yet and if I do I would like to use discrete components.

This is an impedance graph of my DIY 3 way build.
Two Satori WO24P (8 ohm nominal) woofers in parallel
One Scanspeak 18M 4531 Mid Range
One Wavecore TW030WA11 Tweeter
The final Crossover is all 2nd order stuff. But the impedance graph is a bit concerning. I use Class D Ncore and Purifi amplifiers which are rated for 2 ohms. The load dips to 2 ohms between 200 and 300Hz. It also dips to 2.4 ohms between 75 and 200Hz. Otherwise it looks clean. How concerned should I be?

As title says ...

I got my hands on (could not resist bringing home the famous oval driver) these speakers. Doesn't look like DIY (serial numbers on it) but might be a kit.
Can someone help identify what I have?

I want to hear your comments between GaNfet and Purifi in terms of sounds. Which one has lower distortion?

I know most class A/B amplifier has DC offtset even at a very low level. Therefore, which one has lower DC offset betwen GaNfet and Purifi?

Thanks!

I don’t know whether this has been brought to attention here before, but in 2015, TI produced extensive series of brief video-introductions on op-amp design issues and use, which I hadn’t stumbled across before. So, maybe some others haven’t either. Under the sub-topic titled, “Low distortion design”, there are four videos. Most of which are less than 15 minutes in length. I recommend at least viewing the fourth video there titled, “External Sources”. It goes over sources external to the op-amp which can provoke distortion, such as supply regulator output impedance, input and feedback capacitors and SMD resistors.

https://www.ti.com/video/series/precision-labs/ti-precision-labs-op-amps.html

I am trying to decide between OB and Ripole sub bass for a high SPL 4 way OB.

Crossover will be either around 80hz to two 15" woofers or a little higher, 120-140 to a single 15" woofer.

I am looking at 18" drivers and the main problem with ripoles is cavity resonances at ¼ wavelength. For 18" that would be around 180hz.

What if I mounted the 18" drivers on baffles with 12" holes. That would reduce the chamber depth by 3". The chamber itself could flare out from 12" at 9" depth to 18" at the mouth creating a short horn of sorts.

1. Would it work?
2. Has this been done?
3. Can it be modeled?

This would be the ultimate OB bass foundation.... 4x18" in Ripole configuration up to 80Hz and 2x15" in concrete baffles up to 400hz.

For a stereo pair that would be 8x18" which would equal 2 ½ x the Fostex 31.5" woofer.

Dear friends.
The CD player came with a rotted tray gear. After replacement I found the disc does not spin at all. When loading a CD or without CD, the motor very slightly nudged.
No service manuals but found out its nearly identical to the CEC CD2100 and has found the service manual for that.
But the document has no voltage markings so I am working blind. What voltage is sensible to test the disc motor so I can rule out the motor is faulty?
Is there a common issue causing the motor to not spin?

Picture is of a similar model (but not mine).

Hi!

I have lived with a crappy bluetooth speaker for years now and it's time to upgrade. I have realised I do not have the time, place or skill to design a speaker myself but I do have 2 hypex FA123 amps collecting dust from the time when I thought I did!

I was looking to buy when I stumbled across the SEAS King Ro4Y MKIII kit yesterday. It uses the hypex FA253 and they even provide the crossover files etc so you don't even have to design the filters yourself! This was a revelation to me, I did not know these kinds of kits existed!

Since I already own the FA123 I am now searching for a 3-way kit using the Hypex FA123 and where the filters are provided. I feel confident enough to assemble everything myself, I might 3dprint everything even since woodworking in an apartment isn't fun.

What I have found so far is the aforementioned seas kit (If the FA123 is enough for this kit)
https://www.seas.no/index.php?optio...=583:seas-kingro4y-mk-iii&catid=66&Itemid=345

And then @Kwesi in another thread pointed to a german site with a couple of kits that are extremely tempting, if anyone knows anything about this company/these kits please feel free to share! Bliesma tweet/dome mid plus satori wo24p woofer/s.
https://www.ari-acoustics.de/c/opera

I am leaning towards the bookshelf (Ernani) from ari-acoustics or their double woofer floorstander (Nabucco) but would like to know if anyone has any experience with this company and if their kits are any good? And if so, bookshelf or floorstander with my FA123?? What would you choose if we disregard the price? One is designed for the 123 it seems while the other can use the 123 with a small hit do dynamic range?

Any other suggestions in a similar vein?

Only for listening to and recording music/jamming (guitar/piano) in a non-serious way, will be moving soon so the room is not a constant but will be in a living room of probably a smaller size for all to enjoy. I have no idea what kind of speakers I prefer so all suggestions welcome?

Thank you in advance for any suggestions/tips, I would consider any design as long as the filter files are available.

Who can tell me the specifications of the fixing screws for this connector socket? I lost them. I tried using M3 screws, but it was clearly not working.
Could it be some special model? Can anyone tell me the model of the screw or where I can buy it? Thank you.

I previously built Valeria, a compact bookshelf speaker using pro-audio drivers, namely a 6.5" mid-bass and a 1" horn-loaded compression driver. The dynamics offered by this small speaker are impressive, if I may say so myself. It’s currently serving as the center channel in my home theater.

Lately, I’ve been thinking of building speakers with better bass response (a subwoofer will still be necessary though) and improved horizontal and especially vertical directivity. This necessitated using an 8" mid-bass driver, a compression driver that rolls off below 1 kHz, and a horn that can control directivity better than the B&C ME10 I used in Valeria.

The mid-bass driver I selected for Valkyrie is the Lavoce WAF082.00. It has a 2" voice coil, a paper cone, and a cast-aluminum basket. The compression driver, Lavoce DF10.171K, features a 1.75" voice coil and a polyimide diaphragm. As for the horn, I decided to use the RCF HF101, a cast aluminum horn with relatively compact dimensions, which is important to minimize driver-to-driver spacing and consequently improving vertical directivity.



I designed a compact cabinet with internal bracing that couples to the drivers, making the drivers part of the brace and reinforcing the front and rear sides of the cabinet.



The braces were made of 16 mm beech plywood. I attached the braces to the cabinet walls with 3M VHB tape instead of regular wood glue. The soft layer in between acts as constrained-layer damping to reduce resonances.



I decided to use a 3rd order LP and 2nd order HP for the crossover along with two notch filters for the compression driver. The crossover frequency is approximately 1 kHz.



It’s critical to add absorption material to manage the reflections and standing waves that form inside the cabinet. I lined the walls with felt and placed extra-thick 60 mm pyramid foam on top while leaving enough space for the drivers.



Pictured below: Valkyrie standing next to Valeria. Valkyrie’s dimensions are 24 x 42 x 21.5 cm (WxHxD), while Valeria measures 19 x 33 x 22.5 cm (WxHxD).



So, how is the sound? By itself, the bass is lacking, as expected. However, as soon as you add a subwoofer to the mix, the missing low-end is filled in, and what you get is effortless dynamics throughout the entire frequency range assuming the subwoofer can keep up with Valkyrie at higher volumes.

In listening tests, it’s immediately apparent that, compared to Valeria, the bass is considerably louder and deeper below 200 Hz. Otherwise, they’re well matched.

The impedance plot looks clean, with the exception of a resonance at around 300 Hz. This appears to be inherent to the mid-bass driver’s construction, as the free-air impedance measurements of the driver show it as well, albeit not as pronounced. The nominal impedance is 6 ohms dipping to 4.4 ohms at 210 Hz.



The frequency response is within ±3 dB from 100 to 20,000 Hz (quasi-anechoic measurement). The mid-bass to compression driver crossover frequency is quite low at 1 kHz to help make vertical directivity well behaved. A subwoofer is necessary for good bass response.



The horizontal directivity is ±45 degrees nominal, smooth down to 800 Hz. Below that frequency, the directivity quickly becomes omnidirectional. Thanks to the uniform directivity, the frequency response can be equalized without any issues.



The vertical directivity is ±35 degrees nominal, and it’s smooth down to a respectable 1200 Hz. As long as your ears aren’t below around 15 degrees of the horn’s center axis, the timbre of the speaker shouldn’t change noticeably regardless of where you sit or stand.



Last but not least, a complete build video is available below. Please let me know what you think.

Login to view embedded media

Hi all. I'm new to this group, but it seems full of very knowledgeable people and I wonder if you'd be able to help me out? I have a pair of mission 770 freedom Mark V which I really do love. I keep on comparing them against other speakers and they keep on coming out better however looking at the crossover I see that one of the resistors has got so hot that it's melted the plastic that has attached to so I think there must be some serious need for replacing some of the components such as the resistors and capacitors. Of course these are 40 yrs old and I'm a rank amateur in recognising and decoding the codes on the components so that I can replace them. Anyone to hold my hand through this would be much appreciated. Note I have looked at other posts and there is nothing that answers my questions. .

1. Do Resistors generally need replacing? Should they get so hot? code ERG 5.8 ER 4R7J -all i can see. I was advised there are differing values present
2. There is one bipolar cap - code 93-8730 . What is the replacement value?
3. There is one film cap 4u 7K100 Apparently these do not need replacing?

Many thanks

Newbie trying to repair
Hi,
I have salvaged tiny phono module from non working technics amplifier. Please see attached picture and schematic. From my newbie perspective it looks like the phono module is fed supply from approx. 0-30v transformer by making it dual (+ve 0 -ve) by adding capacitor and resistors and probably diodes ./? (see red circled parts.)
I have completely discarded rest the amplifier in junk so no longer have it. I only have tiny phono module. It's Schematic (Top corner part of schematic) says it is fed with approx +/-15v).

* earlier I had supplied it with 0-15v single supply resulting in no output. So i thought opamp might be damaged while soldering. I have replaced NJM4562 with ne5532. Will resolder original njm4562 again

My question is if I have (-15v)-(0v)-(+15v) DC where to connect center 0v from dc supply source ? I guess ground for input and output (pin number 2 and 7) are common. 3 and 6 are signal in. 1 and 8 are signal out.





Schematic



Thanks

A while back I bought some old Interdyn speakers (made in Aus) which use SEAS H-211 and 25 FE-W with a simple 2nd order crossover.

Sadly one tweeter was toast, the woofers stopped working and the boxes had moisture which made them swell and crumble, so I took the drivers out and decided to experiment with rebuilding them.

The woofers had corrosion on the frames, and the speaker terminals had fallen out of the mounts. I cleaned them up, glued them in place and all was good again. I used Glycerol to recondition the rubber surrounds.

For the tweeter that wasn’t working, I ordered some new domes/voice coils from AliExpress, replaced one and it worked ok, so I put the drivers away thinking I could use them as spares for some other speakers I had.

About a month ago I saw some old empty Philips boxes for sale, which were the right volume for the woofers and with holes roughly the right size, so I thought that I’d have a go at restoring them.

The boxes had a nice veneer but quite thin timber so I added some internal panels and bracing.

I replaced the caps in the crossover, hooked them up and was pleasantly surprised with the sound.

I ordered some ferrofluid for the tweeter that had the new dome and it was better again. So I replaced the voice coil on the old tweeter, and to say I’m impressed with the result is an understatement.

I have been trying to design a 3 way MEH, so far I have built a prototype with a 3d printed throat and MDF horn.

I have been measuring and adjusting different things but can't get it over 900hz.

I modelled it in Akabak with the front chambes in LEM then the ports and horn in BEM



My BEM sim in Akabak goes up to 2khz (Red is sim, Blue is measured) but in reality it drops off above 900hz ish





For the drivers I am using four B&C 4NDF34 I have modelled and printed pieces to make them closed back and reduce the rear volume to 0.1L each.

The tape was temporary to hold the rear chamber pieces, I have hot glued the back pieces onto a single driver and am just measuring one at the moment. I did measure with them taped on and there wasn't much difference.

I have measured the impedence of the drivers and compared them to a sim with just a 0.1L rear chamber and the impedence peak is in the same place so I think I have got that part correct. I got a 3d drawing from B&C and modelled it on that to work out the rear volume.



The below is my last measurement: (I didn't save it so don't have the data to make a proper graph)



I have tried adjusting the tap length and front chamber volume but not managed to get it any higher.

The area at the taps is ~19.33 cm^2 and they are 3.5cm away from the compression driver which makes me think they should be able to play above 900hz easily

Currently the compression ratio is a bit high so I am tempted to forget about going above 900hz and move the mid drivers further away from the comp.

Has anyone got any advice for how I could get the mids to go a bit higher?

I am looking for a source for very small tube preamp transformers. I need to power a single 12AX7 so I would need around 220-250VDC at 5-10ma and 6.3V at 300ma

anyone know where i can find a small transformer like that? I can't seem to find anything that small.


Zc

This could very well be a little bit underwhelming. However, I have a Tropo 10in that I would like to switch since it is an under the seat box. The box has .85 cuft sealed, now that's the problem. I understand .85 isn't crazy, but this subwoofer calls for 1 cuft ported. I've been doing some models on SpeakerBoxLite ( I don't have WinISD) and it seems very promising. However, the port is the current issue; I am not fully set on a design just yet because of port velocity. Also, I think there are better minds on here that might be able to help. I have a 3d printer, so I can build any type of port. The truck that it is in right now is a 2018 Ram, I was thinking of making that long part of the box into the port but I am open to suggestions. If a port came out the back side I would have the ability to have part of the port outside the box. I want to aim for 38hz, since that seems to be the best for a flat line. However, it has 30m/s port velocity. Which I know can affect the performance of the sub.

Hello Guys, I want to buy the board from my thread title. I need only the board. If there are no boards, I can try making one by myself, but again, I would appreciate your help choosing the best option.

Removed from some working Rogers pro9tl speakers

Looks like they’ve been recapped at some point.

£60 + p&p

Tants and capacitors replaced

Excellent cosmetic condition

Boxed ( not its original Nat02 box )

£400 + p&p ( I’m uk based )
Collection MK5

If I’m to double box it it may take a while for me to get a suitable box

Obviously this listing is for the Nat02 only .

Only selling to fund the next hifi purchase which can’t wait

No offers please

Removed from some working ls3/5a speakers ( of sorts 😁)

Falcon 23aB (x2 )

£80 + p&p

Less and less people use analog crossovers, including me, so I was wondering about the best crossover devices when wanting to use only AES connections, which are more common in professional equipment. In other words, lets make list of Digital Audio System Processors or Digital Loudspeaker Management Systems that match this description. I will then purchase the most suitable one and then we will see how it performs compared to the traditional Minidsp devices that I have had many over the years. Minidsp of course does not have such AES equipped 4-way product available, otherwise I just might buy that one. 2-way they do have though.

Completed and ready to use with good parts.Mundorf Evo Silver Gold oil caps,Takman resistor......
Used with top results for about a year(200 hours).Price 50 euro plus 4,90 shipping inside EU!Payment paypal for friends.
If tbe buyer will I can sell 2 Nichicon Super through outlut caps for mofo amp.This are the best sounding from Nichicon.Price 30 euro for a pair!

Help
May i know what is the difference between FFT and RTA??? are they the same ????

1) What i found in sound check, both of them are seperated.

Spectrum analyzer

Real time analyzer


2) Meanwhile, FFT is inside the RTA for the REW



Could someone explain the difference？

Hi everyone, due to utter boredom i desided to build some amps for fun. I wanted to start from a quasi complimentary amp designed by forum member WhiteDragon but later i thought why not begin with a simple classic design like DIGI125 (ETI, MAY 1989). I hve drawn a schematic based on the original design with very few modifications like bootstrap, zobel etc.

This is for anyone that still has a Yamaha R8, maybe R9.
If your plastic arms on the garage door type knob cover have broken, here is an STL file for a 3D printer.
Mine were broken, so I created this file and printed out new arms to restore the folding cover functionality.

https://www.thingiverse.com/thing:6871076

Hi all,

please may I have aschematic of below driver card

In 30+ years of DIY speakering, I've never considered building a sub before. A recent acquisition of a used pair of KEF LS50 Meta & a simultaneous request from my son to make him something that can give near nightclub levels of modern electronic music (with the LX521-ish clones I made him last year) is making me think about subs.

I'm considering a hifi sub with SB Audience Nero-15SW800, a pro 15" driver. Specs look great for a pro subwoofer -- Fs=31Hz, Xmax=14.27, AES power=800W. Rated 96 dB/W but this looks optimistic, tho it's definitely >90 dB, amazing for an 8 ohm model (at least in home hifi).

My ideal target is -3 dB to 30Hz, up to 110 dB@1m, capacity to run up to ~120Hz. Willing to feed it >600W.

Not sure if that's realistic.

Madisound says... "Vented box of 4.0 cubic feet with (2x) 3" vent by 6" long for a 3dB down of 35Hz. 6dB down of 28Hz". That's pretty close & room gain might bring it to my target.

The diyaudioandvideo speaker box enclosure designer says...
Butterworth B4 -
Vb = 3.22 ft3 (91.07 lts)
f3 = 36.91 Hz
fb = 36 Hz
Dv = 6 in = 15 cm
Lv = 13.75 in = 33.65 cm

https://subbox.pro/ says in a 18x18x28" box (~4 ft3), a 1.4" slot 6.2" deep and the width of the 18" face will give 36 Hz tuning.



The woofer choice is not firm, but I really like this driver, which was pointed out by Joseph Crowe. He compared it favorably with a TAD TL1601B -- a US$1750 driver-- that he used in his horn loaded bass enclosure. Solen retails the Nero-15SW800 for CA$447.

I have not ruled out other enclosure types, but 4 cubic feet is about as big as I can go. I chose ported because it's the most widely used & even tho the shallower 12 db/oct slope of a sealed box is better for deep bass, I want to keep the excursion low to ensure my son gets all the bass he wants. His room is about 14 x 22 x 10 (ceiling), with big doorways into other parts of the house. I figure ported will limit excursion down in that 30 Hz region. A sharp 24/48 dB low filter will likely be applied ~20 Hz, depending on subjective perception in actual use.

Suggestion, direction, insights about design & construction are most welcome.

Does anyone have Chauncey Epperson's single piece PCB for Dynaco FM3? I would like to rebuild an FM3 and wanted to start with that. Or if anyone is aware of a different board?

We discussed previously whether or not EnABL would improve a MAOP driver, and I volunteered my MAOP-7 to try it. Sorry, couldn't do it earlier. Preparations for winter occupied most of my time - I live in a countryside.

First, I tried to do tap test to determine optimal positions of the patterns. It didn't work - at any distance on the cone radius tap sound was the same. Tapping worked on a 4" Sony speaker with a paper cone, I could find positions where tap produced the loudest sound. I guess the MAOP cone is pretty well-damped as-is. Without tap test guidance, I decided to apply patterns 1) close to surround; 2) on former close to cone boundary, and 3) on top of the dome. See pictures for details.

The patterns were applied free-hand using extra fine Utilto acrylic paint markers, black and white. Surround pattern was applied to back side of the cone to conceal my ugly handiwork. To build up thickness (pens lay paint pretty thin), three layers were applied: black-white-black. On the cap, a single layer of white.

The difference showed on the first test record, Beatrice Rana Chopin Preludes. This is a very well recorded piano album. The second prelude is played between piano and pianissimo. Control untreated driver played soft, but with the EnABLed driver I could hear string buzz that wasn't apparent before. Those familiar with the sound of top level instruments like Steinway or Fazioli will understand what I am talking about.

Further testing is unnecessary. It worked.

New in box.
I over ordered not knowing there are 2 drivers per carton.
So 4 drivers for sale as a package.

If you order 50 at PE they are $135.00 each and 90 days out.
https://www.parts-express.com/Tang-Band-W8-740P-8-Subwoofer-264-854?quantity=50

$400.00 plus shipping, payment via PP FF.

Each carton weighs 23lbs and is 20x10x7 shipping from 55373.

Hi Everyone. I've been enjoying audio gear for about 50 years and over the last 5 years have been working to get more of a technical understanding of audio components. I have a pretty nice basic workshop at this point and have progressed from complete amp and preamp kits, and recapping and refurbishing some of my old gear to sourcing boards, transformers, rectifiers/regulators and then drilling and cutouts on different cases to make a few preamps and amps. It has been quite challenging without any formal training in electronics but I've learned some things are I'm beginning to make some sense of it now. Still, I'm essentially a beginner but enjoy the challenge of learning as I go.

I hope that I can learn even more by being a member of the diyAudio community. Thank you!

--Jonathan

I am a veteran recording studio technician who's always looking for solutions to real world audio problems. Additionally, I'm constantly having to locate obsolete components or obscure technical information in order to keep the vintage equipment I work with functioning properly.

I have a DIY Hypex DLCP preamp and 3-way active crossover that I'd like to give away. The unit works perfectly and comes with the programming software, manual and remote control. The DLCP is meant to be the heart of a 3-way active speaker. It can also be used as a preamp with digital EQ. It is limited to 96k digital. It includes Hypex Filter Designer software to measure the frequency response of drivers and create crossover and EQ filters. You can download the spec sheet manuals at: https://hypex.nl/dlcp. I'd rather not pack and ship this guy. Local pickup in San Jose, CA preferred.

Hello all,

I have a pair (x2) of beautiful Meyer Sound MS818-HTS 18" 8-ohm Woofers that are looking of a good bass cab
I believe they are spares from a theater and appear to be unused, therefore in perfect condition
Cast frame, heavy duty accordion surround, ferrite magnet, used in several Meyer Sound subs
They are big and heavy so probably only suitable for shipping within Australia?
I'm thinking USD 600 for the pair is a fair price but open to offers

Cheers, Ralph




https://audiofile.net.au/

Hi all. I'm new to this group, but it seems full of very knowledgeable people and I wonder if you'd be able to help me out? I have a pair of mission 770 freedom Mark V which I really do love. I keep on comparing them against other speakers and they keep on coming out better however looking at the crossover I see that one of the resistors has got so hot that it's melted the plastic that has attached to so I think there must be some serious need for replacing some of the components such as the resistors and capacitors. Of course these are 40 yrs old and I'm a rank amateur in recognising and decoding the codes on the components so that I can replace them. Anyone to hold my hand through this would be much appreciated. Note I have looked at other posts and there is nothing that answers my questions. . Many thanks

Does anyone else here service these Class H Crown Amps? I can fix them about 85% of the time but have hit a few roadblocks due to their complex nature and seek some guidance. Thanks.

SOLD to birdbox

As the title suggests:
For sale, boards from Zen Mod 2018 (stuffed) with pair of 2SK180 mounted on aluminum Tee bar (12") and pair of Cinemag CMOQ-4HPC (high Nickel) transformers.
These were removed from my case as a working setup. I just have too many amps and want to try something new.
I used a 23 volt +/- DC power supply. All settings should be good to go in your new case. I cut the power wires off at the board so as not to heat the board excessively.
Asking $275 OBO plus shipping. PAYPAL friends and family
I prefer USA transactions due to weight with aluminum T bars.
Please PM with zip code and phone number so I can determine cost to ship.

I have a brand new pair of silk dome drivers from Bliesma. Never mounted. Price is $750 (plus PayPal fees) shipped in US. Thanks for looking.

Hello,

I am new here and fairly new on my journey on building a high quality speaker project. I am a residential architect that recently rekindled my love for great sound and I am diving into the world of product design with my first attempt at designing an auditorily and visually beautiful enclosure. Before I begin ordering drivers and start the actual build, I am trying to select components that will serve as a great foundation for driving various iterations as I go.

My end goal is to build a pair of 3-way speakers for audiophile grade music listening with a frequency range between slightly below 20Hz to 40khz. I would like to drive each tweeter, mid-range woofer and subwoofer individually with either a single 6 channel amp or most likely discrete amps for each pair depending on the power demands of the individual drivers.

I found various drivers (from SEAS, Scan-Speak, Mark Audio and Tang Band)

One possible pairing might be:
-Scanspeak Illuminator D3004/6640-00 1" Tweeter Beryllium Dome - 4 Ohms
-Scanspeak Illuminator 12MU/4731T-00 4.5" Midrange - 4 Ohms
-ScanSpeak Revelator 26W/4867T 10" Woofer Black Aluminum Cone, 4 Ohms

Another might be:
-SEAS E0121-04/06 C16NX001/X - 4 Ohms - 100W (coaxial mid and tweeter)
-SEAS XM001-04 L26ROY - 4 Ohms - 250 Watts

For amplifiers, Emotiva seems to fall within my budget and criteria. (open to suggestions on this and everything else)

• For Tweeter and Midrange woffer: Emotiva BasX A4 Four-Channel Power Amplifier 130 watts per channel - 4 channel @ 4 Ohms ($549)
• For Subwoofer: Emotiva BasX A2 Stereo Amplifier 250 watts per channel - 2 channel @ 4 Ohms ($579)

Now I am on the hunt for a pre-amp DSP with at least 6 channel output capable of the wide frequency range I am looking for. It would be great if it also includes room correction features.

So far I found the miniDSP Flex Eight ($549) and the Octo dac8 Pro ($1,300+/-). I might be wrong, but I believe those both are limited to between 20Hz and 20kHz.

Being new at this, I am very open to suggestions, tips and tricks on the best practices for equipment matching. In my case I'd like the dsp/amp setup to be somewhat flexible for various driver configurations I might try along the way. As for budget, I would like to keep it reasonable, but open to spend a little more for valuable features and high quality.

Thanks and looking forward to the journey!
-Chris

The last week or so I’ve been getting an intermittent static in one channel of my Aleph J. It comes and goes. Sometimes quite loud then later almost disappears. Amp is four years old and has been very reliable and basically dead quiet until now. I opened it up and don’t see any loose connections? This is a dual mono amp with two separate power supplies in one chassis if that’s relevant.

For sale a complete high resolution DAC Lynx Audio D-35 based on AD1862. This is by far a best implementation of AD1862 . 4 layers PCB with a high grade components.
Asking 300US plus the shipping. AD1862N-D grade chips are included.