Hi. A friend and I have recently rebuilt the cabinets for some KEF CS5 speakers. We made router templates for the KEF B200G and KEF BD139B drives. The B200 are the rounded triangular type. I switched out the tweeter so there is also a template for a Scanspeak D2604/830000, which I guess is of less interest. If these are of use to anyone in the UK, they are yours for cost of the postage. Photos attached.

My 2005 Toyota RAV4 has 2 Key wires and a ground for SWC, while my new head unit with built in interface has one dedicated key wire.
I grounded the yellow wire and connected my car’s Key1 to the unit’s Key wire, leaving out the car’s key 2 wire which corresponds to the 5th “mode” button on my steering wheel.

Can I twist my car’s Key1&2 wires together and connect to the unit’s Key wire so that I can use that last missing button, or is that a bad idea?

Hello fellow DIY'ers,

After much research and a few bumps along the road, I've decided to create a new thread to centralize (but hopefully not duplicate) information about making your own DIY Record Cleaning Fluid(s) - abbreviated as RCF's below...

From my research, I can tell people are passionate about the topic, and report satisfaction with a wide variety of fluids and regimes. I readily acknoweldge I am not a purist, or even an audiophile... I just want my records to sound as good as they can within my limitations and also acknowledge my bias to spend less time cleaning, and more time listening, and spend as little money as I can doing both.

I invite diyAudio members to share their success stories, or link to a post that they find useful... think of this as an on-going brain-storming session...

I will post links to relevant threads to make it easier for readers to make up their own minds based on what others have done before...The first link below is what got me interested in researching this topic further:

• "My Version of an Ultrasonic Record Cleaner, a thread created by member BBFTX" "Post # 1420 by member RRushton": My version of an Ultrasonic Record Cleaner

• The AudioKarma thread referenced in the first link above: Record cleaning- you're doing it wrong! | Audiokarma Home Audio Stereo Discussion Forums

• 
  A (Very Long) Primer on Record Cleaning Fluids: A (Very Long) Primer on Record Cleaning Fluids | Steve Hoffman Music Forums

My next post will share where my research has led me so far, which is a Word document I found on the web, by the author of the AudioKarma thread referenced in the link above.

I have a Philips NOS E88CC valve - can it be used as straight swap for ECC83 ???????

Hello,
Yesterday I received a pair of speakers from a Mr. Radu Tarta. I purchased them from him through this site and could not be more pleased with the entire transaction. From the absolutely beautifully crafted speakers to his generous handling of shipping fees to how well these were packed for shipment. Radu is truly an artisan and a gentleman. I’m inspired by his example and would encourage anyone to look closely at what he has to offer. Be it speakers, amplifiers, preamps or any other offerings. I’m not given to undue praise but in this case it’s simply impossible to ignore the obvious care and attention to detail he brings to his work. This world of ours is a crazy mixed up place. Many times profit appears to be the most important factor especially it seems when it comes to audio equipment. We are all here, at least to some degree, seeking better value as well as the satisfaction of building something ourselves. Radu is a prime example of someone who cares deeply about his work and imho the best of what this community has to offer.
I’ve only recently returned to this group after several years away and buying these speakers from Radu has been a wonderful re-introduction. I’m looking forward to perhaps working with Radu again and to enjoying this wonderful community. And of course these fabulous sounding speakers.
My best to Radu and this group.

Is my first crossover design any good? And other Noob questions

Hello, i designed my first crossover today and wanted to know, what you think about it. Im using as midwoofer the tcp115 4ohm and as tweeter the ND16FA 6ohm

I hope this is the right place to ask, if not im sorry
The Crossoverdesign:

In later post

The Components:

In later post

Lastly i wanted to ask if im right with the impedance of 10 ohms
and if :this super cheap amp from ebay is any good and if not i would like to know, which amp i could use(preferably a cheap one)
I choose 100w for the amp because i heard you should double the rating of the w the speakers are rated for (i have no idea if this is true, is it?).
Thanks!

--------------- Not required any more, thanks for looking ----------------------

Do you have any parts languishing in your "to do" pile for an Aleph J?
Looking for PCB/Kit/Parts.

Also looking for MoFo parts.

Prefer UK location, otherwise any where else subject to postage costs etc

Let me know what you have.

Thanks.

What have people been using to adhere 1/2" wool felt to speaker interior panels? I used double sided carpet tape for the last build, seemed to work but I'm always open to other suggestions

One of the most fascinating resources I've ever come across. Each individual instrument is recorded with a total of 22 mics in an anechoic chamber, with the musicians wearing headphones and watching a video of a conductor for proper timing.
Watching an RTA with a mic in front of a speaker is pretty revelatory for seeing fundamentals and harmonics of each instrument without the influence of a room acoustic. Make sure you put the RTA on it's quickest setting(8khz FFT)and the mic as close as possible to the speaker(Within reason🙂)
I imagine that it's been posted on this forum before, but I couldn't find it with a basic search, so..

Anechoic recordings of symphonic music - Department of Media Technology

Hi, working on a project and need replacement replays. From online searching its a 8 pole double open and double closed?

The model is SZ-2104 24v.

I searched online and this came up:

MT2-C93419
TE Connectivity, 24V dc Coil Non-Latching Relay DPDT, 2A Switching Current PCB Mount, 2 Pole

is this correct type and a decent replacement? Thanks any advice appreciated.

There are several threads about vinyl cleaning, but vinyl inner sleeves are marginally mentioned. Let's discuss the various materials, which is preferred, which is to be avoided.
Sleeves could contain and release visible and invisible particles: debris, plasticizers. They could chemically or physically harm the LP. Although their purpose is to protect the vinyl during storage.
I met the following inner sleeve materials:

• Paper with a round cutout at the label
• Thick paper, internally smooth, with cover art
• Paper lined with (?) polyproplene
• Soft polyethylene
• Polypropylene (?) - some more thick, opaque, rustling plastic

It is annoying when you remove the LP from the cheap plastic sleeve, and it gets statically charged so that it immediately attracts dirt. I found this product:
Nagaoka 102 Anti-static Record Sleeves
Do you routinely replace the not-so-good inner sleeve to a better one? If so, right after purchasing, or after the first wet cleaning?

Hi All.

So i'm trying to fix up my Logitech z-2300 2.1 speaker setup that i bought ages ago because i have an affinity to it. I have an issue that i need to fix and am looking to get some input on it. The issue is as follow:

The rubber surround on one of the satellite speakers cracked at some point, i'm assuming from temperature or overuse. I ended up cutting out the cracked parts, but the speaker still crackles with the right notes/tones/volume. Can someone point me in the right direction of places to buy decent, good value rubber surrounds, the right adhesive to apply to it, and tips on the process?

Pair of Dayton RS270-8 10 inch woofers for sale. Excellent condition.Reduced $90 for the pair. see pics. Buyer to pay shipping.

I don't understand the difference between the two. Some manufacturers say their crossover topology is 1st order, but it actually is electrical 1st order but not acoustic. What's the difference? Does the electrical crossover not have a 6db slope? How does relate to phase?

Thanks for any help that can shed light on this.

Hello all,

Maybe a stupide question, answered many times.
But i can’t find a answer that i understand 🙂

If i use a PC with USB to Dac, set output in PC to say 24/384.
Dac say 384 kHz when play music.
But the music i play is recorded in 16/44.1.
Is the pc doing upsamle then from 44.1khz to 384khz?

Reason for asking is that i think music sounds better in 384 vs 192 kHz.
Maybe just placebo..

BR// Daniel

Hello,

I'm trying to get ferrite or laminated audio inductors in the 50mH-2H range, ideally custom wound ones. In my search I found the following sites:

Finest Audio Inductors
Inductors
Inductors
EQUALIZER (EQ) INDUCTORS
Classic Audio Products, Inc.
https://cinemag.biz/inductors/inductors.php

Either there is no answer on my request, or they are out of business, or vendor does not have part in stock or cannot provide requested info (DCR of inductor they selling). Can anyone point to the reliable source of audio inductors, preferably custom ones?

Hi there,

I have a pair of Technics SL-1210 MK2 turntables. There is a huge database of mythology about how various add-ons created by various companies can improve the sound quality of these and I was wondering if anyone has any views or experiences on some of this stuff.

I can neither afford nor want the hassle of an external power source and I am already using a decent cartridge so the potential next step for me would be to consider a tone-arm upgrade. These are rather pricey. Moreover, there is a school of thought that suggests that the biggest problem of the Technics arm is the cheap quality wiring in and this has got me thinking that maybe I should try that first.

At first look, the idea sounds like poppycock to me...I am one of those people that make their own interconnects by braiding cheap and cheerful solid core wire and am convinced that it sounds as good as oxygen-free-cryogenically-treated-special-alloy wire in some-near-extinct-animal's-leather sheath. This having read a few things about the theory behind it and having listened (or rather not listened) to the difference between different cables.

Nevertheless, I always like to keep an open mind. So, running the fear of starting up another behemoth of a thread like the "do cables matter" one, can I please ask people's opinions on whether tone-arm wire quality really matters?

Thanks,
Nikos

Do you have any parts languishing in your "to do" pile for a AKSA Lender?
Looking for PCB/Kit/Parts.

Prefer UK location, otherwise any where else subject to postage costs etc

Let me know what you have.

Also looking for MoFo parts.

This tube preamplifier, Elekit TU-8500 seems like the best deal going for a quality tube preamplifier. Comes from Japan as opposed to China. Seems like Victor Kung offers great support. You can buy it as a kit to save a few dollars (under $600 depending on options).

Why not more discussion here and other forums?

Anyone have one that could offer a short review?

What are the alternatives that I'm missing?

Greetings,

I'm putting together an amp with 300V across the anode resistors. I read on Tubecad it is better to use multiple resistors than one.
"There is a voltage distortion mechanism in many resistors that is so small at low voltages that it is usually disregarded, but in a high voltage circuit, such as this one, the distortion becomes an issue. Using six resistors in series reduces the resistor distortion by six fold."

I'm ordering parts, and I must say I'd much rather use one big high power resistor than six smaller ones. Would it be much worse?

Thanks.


The Tube CAD Journal, Electrostatic Headphones

Hello everybody.

I have a 300B stereo tube amp.

For a few days when I turn on a channel it makes a loud clack, ploc, plop, like two seconds after turning it on.

When I switch the 300B valves sideways, the noise changes channels. Could the 300B be broken?

Removed from my Elipsons .
There is a small nick in the outer edge of the cone on one driver.
These are the original legendary ( apparently) 1960’s drivers .

Please note that these are the SRTF not RTF.

Collection from Milton Keynes.

£450

I have this kit: Fostex BK-12m Folded Horn Kit - Pair

With the FE126NV installed. I see the FE108EZ is offered as an upgrade.

Are they necessarily 'better' or just different in terms of the sound?

Or, are there other drivers that could be a bolt-in replacement that would be enjoyable (that would work with the existing cabinet).

Just staying with what I have is fine, I am not trying to upgrade for the sake up upgrading, just curious.

Any one got spare KSP42 / KSP92's or direct pin equivalents? For Gilmore Golden Reference PSU.

Looking for 10 or 20 of each

Hi guys.
I try to fix this Marantz SR7200 that gives loud buzz noise in all modes. When switching a direct mode, sometimes noise disappears, sometimes not.
I will be glad for any suggestions.
Also, for some reason, access to "hifiengine" from my region is blocked. There is four service bulletins for this model which can help me, but I can't download it. If someone can help ;//
Marantz SR7200 Audio Video Surround Receiver Manual | HiFi Engine

Thanks in advance.

Cheers!

FS JC2 Preamp all set up and working great...just no longer use.

Has Alps Pot too.

$45 + Ship?

Hello all, first time here so please be gentle! 😀
I wasn't sure exactly what board to put this on

Anyway I am running across an issue that is driving me nuts. Live situation. I play a LP through some pedals and then a Radial Pro48 Active DI which splits off to my Vox AC10 and XLR to house PA. I get a nasty hum even with ground lift on the DI. I also picked up a HumX and have my AMP power going into it. Still same hum. I moved the humX to the power of my pedals (MXR ISO brick) but still same hum.

The only time the hum goes away from amp and PA is when I disconnect XLR from my DI. I don't have access to get into the PA other than plug in and set level.

Do you guys have some ideas to get around the hum? I use my amp to help me monitor my sound and need PA to reach the audience.

David

Hello there,

Here is my setup,

Optical out from TV to SMSL SU-8 DAC, DAC connected to main amp with a pair of XLR cables.

There is no preamp, I am using the remote from the DAC to set volume, there are no sources other than the TV.

The SMSL SU-8 also has a pair of left/right RCA outs that I would like to feed to my Sanway D1-800D mono full DSP (i.e. can set XO with it, etc.) subwoofer plate amplifier that only has one XLR input.

How can I go from stereo RCA out to mono XLR in?

Ideas?

Selling my Tortuga pre because my Exogal Comet+’s volume control works just as well and I would prefer one less thing in my signal path.

I bought it from here: https://www.diyaudio.com/forums/swa...diy-ldr-controllers-displays-buffers-etc.html details are also available here.

I can confirm it works and the Apple remote pairs great. It’s not the prettiest, and the lid doesn’t actually stay on but most prebuilt ones sell for over 3x this so if you can put this in a nicer case, you’d still have a bargain. It also comes with the firmware upgrade board.

Selling for $200 plus shipping, will ship anywhere at cost.

I can take more pictures if requested.

Fostex 166E Full Range Drivers. Planet 10 modified. 6.5” drivers. New in the box. $200 plus exact shipping.

Hi!

I'm finalizing a build of the RH84 SE EL84/12AT7 amp and dealing with some noise issues.

The symptom right now is sort of a buzz that is audible on the left channel only.
This is audible with Sennheiser HD660s headphones which are fairly sensitive at 104dB.

It goes away if the volume pot is at min or max position.
I've read this could be noise coupled to the input wires... I moved a bunch of wire around and it didn't make any difference. The input wires are shielded coaxial.

B+ is regulated with Maida regulator so shouldn't be a source of noise.

I experimented with a regulated DC heater supply and that did eliminate this specific noise, but seemed to introduce a different, barely audible hash.

I ordered parts to try and elevate the heater center tap to about 60V, but is there anything else I can try in the meanwhile?
I have an analog oscilloscope and PC-based spectrum analyzer so can do a few tests and post back if it helps diagnosis.

P.S. The PCB is of my own design, it is the first PCB I've made and so may not be perfect. Although, given that the noise goes away with volume maxed out, I don't think that it specifically is the issue.

Jeff has retired and I was hoping to find one or two as he was a "builder of many tube types" its as much sentimental as it is hi fi quality.....James

Hi guys ...specifically for open baffle subwoofer driver, which is more important ???

High QTS ?? Or Low CMS? Or both?
Or a combination of high QTS and low CMS?
Or a combination of low QTS and high CMS?

Or...what is a reasonable combination of QTS and CMS for open baffle subwoofer drivers? (For 15" or 18" drivers)

I know this has been discussed few times, but it always feels like some degree of clarity is missing. So asking again, please bear with me guys...

And secondly BL also comes into picture which may effect the CMS ....

A recent two-way speaker build has turned into a 3-way speaker build due to inheriting some free drivers.

I've made up a crossover on VituixCAD and it looks pretty good to my eye, except that the impedance seems to drop to 3ohms at 900hz.
I'll be powering these speakers via an old Onkyo TX-SR705 which is rated to run 4 ohm speakers according to the manual.
Would this be a problem and does it look like I've missed anything? I'm an amateur at this and some people on this forum have a wealth of knowledge!

Tweeter: Dayton Audio ND25FN
Mid: Tang Band W3 593FS
Bass: Dayton Audio ND105-4

Crossover diagram: dayton-pc-speaker-3-way-crossover-diagram — ImgBB
Crossover including graphs: dayton-pc-speaker-3-way-crossover — ImgBB

Thanks in advance!

Here is the schematic from a 3020B that was simulated using modern transistors. I thought I would experience the equivalent of audio nirvana when I saw the gain/phase plots of this circuit but I was underwhelmed. To be honest, the gain/phase plots look awful compared to a typical Leach amp. Of course looking at a simulation doesn't tell the whole story. But if it looks and simulates less than stellar, why build it? Some of the blame could be the modern transistors used to make it. I am surprised by the number of small caps sprinkled around the circuit to shape the frequency response. Sure, it's flat +/- 3db 20 to 20K but the phase response is iffy and it appears that there will be stability issues at high frequencies. Blame the modern transistors, I guess. Has this amp been cloned? Does the NAD 3020 deserve it's cult-like reputation??

I guess the search for the audio holy grail continues......

I'm really bad at knowing all the advanced ways to correctly search on the internet. I have spent two days trying to find designs what utilize a couple of speakers I own. I have the 12 inch Kappalite LF woofers in a 3 cu ft enclosure, with endless loading options. Ported sealed all works. Even different size ports are possible.
I also own a pair of B&C 6md38 midrange. The plan is to make a 3 way pair of very high efficiency speakers. To keep it high efficiency, I figured I'd go active with DSP. I'm just trying to make sure there are not any designs already made using these drivers before I start. I also need to find a good hi frequency transducer of some sort. Whether it be normal tweeter, AMT, ribbon, Etc for a high efficiency design. Any suggestions on how to search for this would be very helpful. I don't mind doing the research I just don't know how very well. Thank you

Part number Y236651, 250VA toroidal transformer.

New with original box and mounting plate+bolt.

$35 + shipping (probably $10-ish in the US lower 48), OBO.

A circuit that has no connection to earth/ground/chassis ground, is that correct?

(Of course mains earth has to be connected to the chassis)

I‘m asking because during my builds, I‘m often too impatient and can‘t resist to hook that beast and have an ear full.
The wayne‘s BA18 linestage for example was deadsilend in ... floating? ... state. It is grounded now and still dead silent, haha! [emoji2]

Hi,

I have buy DD12 US (117V), but i live in France and the power supply is 230V.

Can you said how do to change the voltage ?.

A lot of people said must change jumpers on power supply card and amplifier card.

I have contacted Velodyne France yesterday, but they don't want do update (Hamysound)

Excuse me about my english

Thank for your replies

Best regard.

I am new to this forum, and would be grateful for help. Over the years the drawer of my Sony CDP-337ESD became sluggish. Eventually, it would not come all the way out by itself. So I changed the two belts in the KSS-190a transport to new ones. This improved things, but the speed of the drawer going in and out was still not as fast as it was when new. So this time I cleaned all the sticky old grease out from all the gears and put new grease on. Unfortunately, after I put everything back together again, now the drawer does not move at all. The front display says "Open" and "Close". There is no sign of any activity from either of the motors and the CD does not spin. The two Mabuchi RF-510T motors that drive the belts and gears are still OK. Any ideas where I might have damaged the 337ESD?

I've just rebuilt a threshold 400A that was blown in both channels. I used onsemi MJ121195/96.
All seems to have been successful (full power test pending) but I don't have a bias adjustment procedure for this one.


All emitter resistors were changed, as well as all electrolytics except the mains.

Anyone tried using super capacitor (ex seen on ebay : 2.5v 3.3F or 5.5v 4.7f) stacked for a simple dc heater supply?

For indirectly heated tube.

Transformer --- > bridge ---> adjustment resistor ---> Super capacitor

Or for DHT

Transformer --- > bridge ---> adjustment resistor ---> Super capacitor ---> commun mode choke

I recently purchased a pair of Duntech Crown prince speakers that have been in storage for many years. the foam on the woofers is just at that point where the foam is rotten. they haven't fallen apart yet but you can tell one good bass note and they are toast!

SO, I have 2 options.

1- refoam. Now I can have Bill Watkins do the refoam work. he has some sort of special method to align the voice coils in the gap electrically without having to cut the dustcaps off. Dynaudio woofers don't have dustcaps anyway. I did some research and found a place that supposedly has the correct foam surround kits imported from germany. I believe this to be a good way to repair the 24W75 woofers as they are no longer available from Dynaudio.

However.

2- I did contact Duntech and Dynaudio will sell them custom replacement woofers with rubber surrounds instead of the foam. this is a more expensive option but in the long run they will never rot out again.



So those are my two options. There are advantages to both. 1- the stock woofers are matched and voiced to those cabinets. granted changing the foam surround may alter the drivers characteristics slightly? and the spiders could be weak anyway.

Going with new woofers has the advantage of rubber surrounds and possibly be a more advanced driver with better specs i don't know. But will they be as matched to the cabs and each other as the stock woofers?


Thoughts?


Zc

I have vehemently decided that my next speaker upgrade will be hands down a high end PA speaker, definitely want horns for the mids and a 15 inch for that thumping bass. I have been looking at the Visaton Monitor 890 Mk3 and the Calpamos. And although I can get the Visatons for cost price and prefer it in every way, it still ends up more expensive than the Calpamos if I were to buy the Calpamos without the kit and purchase the drivers separately and digital design crossovers. The difference being about $400 US which is essentially around $600 Aussie dollars.

Putting the soap story aside, lets go with the premise that I go with the Calpamos as the base(if there is any objections and a preference to the Visatons speak now) I am keen to change the 15inch driver to one that plays a little better towards the top end as low extension is not important for me. I have 2 Dayton RSS3150HO which play superbly at a QTC of about .44 start and stop on the dime.

I have chosen the B&C 15NDL76 or the B&C 15FW76 to switch with the original Faital Pro 15PR400 if you have better options please feel free to recommend especially if you know about the Calpamos, the horn mid is the Faital Pro HF201 in a P Audio Ph2380 throat horn flare which can easily go down to 650hz in the original design.

Now, I know that each cabinet has its own unique crossover but I am sure DSP will manage everything in its crossover design and corrections to an extent. I am trying to keep as much as possible the existing design and just find the most appropriate enclosure size for the new woofer.

I know enough about speaker design to ensure I haven't missed anything, in particular making sure that both drivers will reach the end of there frequency spectrum.

Is there anything else I need to watch out for before I embark on this possible project?

If the sub woofers are not as sensitive would that be a problem?

For sale a Korg B1 preamp board from DIYAudio store, calibrated and in perfect working order. All the caps are Elna Silmic II
100euro + shipping
Best regards
Guglielmo

Happy Saturday DIYAUDIO FAM ...

I pray everyone that is reading this post and your families are safe and healthy.

Now that I am off work for a while and confined to the house I started repairing a lot of old stuff I had in the garage.

I was wondering if someone could assist me with a project? Hopefully, I am posting it in the correct forum ...

I have the Cameo 4 cutter that I use to make stencils, stickers, shirts, etc. And I was wondering how I could use CAD or a similar program to make a template of my X-Station Keyboard and some Channel Strips. I could create the template and then have the Cameo cut out the template.

I want to repaint the keyboard and then repaint the markings using a stencil-template. Has anyone ever done this before? I have a tendency to overthink things so any suggestions, guidance is appreciated.

Hello,
i have this amp, with a blown PTC in the power supply. In the diagram it is marked as PTC 10... Which type should i order?
I have also a blown transistor. MJ15025G.
Must it On Semi, or can i order ISC? Because its a lot cheaper?


Greetings
Achim

Greetings,

I have a question for the master again.
Can I replace 2sc5200 with 2n6259

I have whole lot of 2n6259 and I Wonder is it
Interchangable with 2sc 5200 for LF amps.

Now that I have finished my SP10 turntable project, I want to build a high end phono stage to meet and exceed it. There is a well reviewed phono stage that has the following published details.

No caps or resistors in the signal path
Point to point
Pair C3g tubes in input stage, 2123 Hz, passive regulated DC heaters
Pair C3g tubes in the output stage, 50-500 Hz, AC heaters
LCR network transformer driven
39 db output level for MM
Step-up transformer for MC
Power supply 6CA4/EZ81 tube rectifier w/choke filter
Input impedance 47Kohm/200 pf
Output impedance 1200 Ohm
Gain 39 db

I found these transformers that have similar construction to the commercial unit. Noguchi Tranformers FMQL and FMQH RIAA equalizer coils.

Are there any known schematics that can be modified or anyone up to the task to sketch out? Or too difficult a task?

Been following this thread:
10F/8424 & RS225-8 FAST / WAW Ref Monitor

I agree with a lot of the theory surrounding this speaker and setup, that's kind of rare for me. Mainly that a speaker should be centered around the largest woofer.

Is there a SS 22w thread?

I like this enclosure for the 22w:
http://www.troelsgravesen.dk/Ellam-3W/ellam-flex-3w-cabinet-large.png

I might have to change the height, but I figure if I keep the length the same it should be okay. Or I might build a ported enclose that is tuned low. But I think I would like a TL.

Which full-range should I use? I like the look of the Seas 3-4 inch or at least a cast basket.

Some things took me way to long to realize:

I don't like highs, especially dome tweeters.

Most speakers have too much midrange and way too much treble, for my taste.

I usually EQ the treble down by 8 db and mids down by 6 db and raise the bass up by 12 db on a 2-way.

I have a "flat FR response" Dayton C-note kit I listen to now and I even have to turn the treble way down and bass way up on the receiver.

Audiophiles "trash" Bose speakers (and I do to 😀), but who is listening to these C-notes? They are PAINFUL 😱 to listen to un-EQed.
I had some Usher 2-ways in the same location.
Bought them from Joe D., the usher consultant. Put every usher woofer and tweeter in them, similar issues to the C-note.
I like Bose 301's better than any domed tweeter speakers I had in that location.

I do okay with ribbons and AMT's and Vifa/SS ring radiator, but I think I can do without.
Maybe a FAST with ring radiator or AMT?
Also I don't know what the acronym FAST stands for

Dear friends,


I am currently building an amplifier chassis for use with M2X and aleph J.


I was wondering if someone could please have a look at the attached design and give me feedback before I order materials. I am not very experienced and not trained.



The design is open source and can be used by anyone. For a quick overview, consult the attached pdf - see below.



If someone would like to replicate the design, the full cad file is available here. However, it is not a stable design as of yet. Also, it requires the builder having access to a 25x30cm heatsink.



My questions are:



1. Anything strange? What would you do different?


2. Are the following items too close to the 500 VA transformer?

• the speaker protection board
• the speaker protection board transformer
• the softstart

3. Do you agree with the distance between M2X pcb and power supply (I have left a lot of "unused airspace" between them).


Thank you!



Please note that I may not reply immediate to this threat as I am currently not well.

glad i found this site i am glad to be here i am a bench tech in the two way communications field but my hobby has always been audio i have built many high powered power amps over the years and getting back into my hobby

Hello everyone, very happy to add the community.
I am Aurelien, from France, live in Spain, speaker design lover, I do some DIY designs like BT speakers or PA systems, I can bring my help on some threads I guess and sometimes I will need yours mostly when I am locked an eletronic problems

Cheers
Aurel

Up for sale, a total of five pairs of unfinished TPA3255 amp boards and power supplies. All brand new.

Each pair includes

• One TICORE260BTL TPA3255 STEREO PFFB 48V (PARTIAL KIT) AMPLIFIER MODULE with the four premium coilcraft VER2923-103KL inductors installed.
• One AliExpress 800w 48v low noise power supply (KAYPW Switching Power Supply Light Transformer, as used by XRK on his builds)

Asking £99 per pair (power supply and amp) plus shipping. Discounts if you want to buy more than one.

To complete each amp board all you needs is:

• One ATS-TI1OP-519-C1-R3 heatsink (available on mouser, costs just over £5)
• 2 pcs OPA1656 or LME49860 on SOIC-8 to DIP-8 adapter ENIG PCB - readily available on the internet
• 4pc tank caps: 1800uF 63V low impedance (e.g. panasonic EEU-FC1J182, about £2 each)

Plus other ancillaries and chassis etc... which are not included.

You will need to make the following easy amend to the boards as TICore260BTL Version "V1A" has a small fault that when right channel exceeds certain power output, the module goes into protection mode. This is overcome by lifting C17, then connect the ground of C17 to ground plane on C16. (Picture attached)

Good performance from these. Any questions please ask.

Gavin
Oxford, UK

I am wondering with 3Dprinting is it possible to make scaled down versions of more uncommon speakers enclosures for headphone applications, such as transmission line. My audio and physics knowledge is very limited, so I am wondering if you guys would help me understand what’s possible. Id like to build some headphones that wouldnt not have been feasible without 3DP.

The most Ive kind of understood is wave lengths and back loaded horns. The reason I learned (sort of) was because I was searching for impressions on madisound’s tiny back loaded horn computer speakers they used to sell a few years ago (cant find on their website now but it came fully assembled and was ~$100pair) and if they actually worked or were just show. It appeared that they werent large/long enough to be effective.

I am a newb that ocassionally browses diyaudio and diyma. I built a pair of open baffle Manzanita Ultras and put together a car audio system where I learned about crossovers and REW. I am mostly into headphones though and actively participate and share impressions & measurements on other forums. Thats a summary of my limited experience and sincere interest.

Please advise what’s possible and if there are computer programs able to simulate results with these tiny dimensions and headphone drivers. Even a program for typical open/closed back phones would be helpful.

Thanks, -Phil

Edit: I am willing to put in the time to understand the basics - just wondering if you could shortcut me to whether its even worth looking into since it may be impossible etc. ... Help me get pointed in the right direction.

Edit2: Also didnt know where to make this thread. Full-sized headphones generally use a single driver. And the miscellaneous subforums look much less trafficked. 🙂

I am trying to connect an after-market DSP to my OEM head unit. The issue is that the signal is not always being output by the head unit. When the system is first turned on with everything connected, the signal is off, but when the RCA is unplugged from the DSP, the signal immediately turns on and stays on after being plugged back in. Actually, just disconnecting the negative side of the signal from the DSP causes it to turn on. I know that the signal from the head unit is not turning vs an issue with the DSP because I have a scope connected to the head unit's output and can see when it switches on.

My first thought was that it is either some load sensing circuit to ensure the expected load is connected, or some kind of protection circuit when it senses too much current being drawn. I measured the OEM amplifier input impedance and it measures at either 500 ohms or 50 ohms, depending on the resistance used to measure it (another mystery perhaps). I tried putting dummy loads of 50 and 500 ohms between the head unit and DSP, but it still only turns on when you disconnect from the DSP. I also tried loads of 47, 250, 1k, 5k and 10k for good measure, and still no luck until I unplug from the DSP and plug back in. What could be going on here?

Selling my DCB1 Hypnotize with all premium naked foil resistors mounted in a test chassis.

$150 plus shipping. I will ship this international, however, be advised that shipping times are very slow right now....

It's currently setup without a pot, I can put a Dact style 10k pot in for you.




Cheers,

Greg

I am looking at chassis options with built-in heatsink and I like Dissipante 2U for my project. It seems that I cannot get its 1mm steel back panel customized for speaker terminals etc.

Are there any options for a 2U case with customizable back panel that has built-in heatsink?

TIA

I recently assembled a 3e-audio tpa3251 amplifier. I was really happy with the result, and thought it would be nice to have a similar amp board built around the tpa3250. I don't need a lot of power (20-30 watts is more than enough), and the tpa3250's power pad down design allows the PCB to be used as a heatsink, allowing for a smaller board. 3e-audio appears to have made a tpa3250 board at one point, but it is no longer available.

I haven't made time for diyAudio projects in the last year or so, and combined with the desire to have a tpa3250 board, I thought I'd take a stab at designing my own. The first PCB I ever designed was for the tpa3118 chip; I called it the Hot Doug, as an homage to DUG's tpa3116/8 board. (I built an amp around DUG's boards over five years ago, and it's been in continuous operation in our living room ever since.)

Also noteworthy is the Gmarsh-designed Wiener Pro prototype based on the tpa3250. He doesn't appear to be active on diyAudio any more, unfortunately.

So here I present the "Hotter Doug" tpa3250 board. This is by far the most complex board I've designed; in the interest of trying to minimize problems, it is essentially a slightly simplified version of the TI TPA3250D2EVM (TI's own evaluation module/reference design). Design notes:

• Fairly compact: 92x73 (mm).
• Component references exactly same as TI EVM.
• I originally wanted to use the "deliciously overkill" VER2923 inductors, but decided instead to use the Coilcraft ua801x series for cost and space savings.
• Uses only 805 or bigger SMD components. This is my personal threshold for what is comfortable to solder by hand. (Also allows for more caps to be C0G.)
• Strictly BTL (stereo), does away with all EVM jumpers except SE/DIFF input.
• Omits the EVM's supervisor IC (for managing the RESET pin) in favor of continuous 3.3v on that pin (copied the idea from the tpa3220evm-micro).
• Nearly continuous bottom layer groundplane, stitched to top layer groundplane, to make whole PCB act as a heatsink for the tpa chip.

My main goal with this version is just to have something that works. Unless I made a copy error, the schematic should be valid, since it's a direct clone of the TI EVM. Component density is high (for me anyway), so my biggest concern is soldering errors. I plan to use my frying pan/skillet method. Assuming everything works, some ideas for future revisions:

• Take measurements, investigate post-filter feedback.
• See if there's a simpler/smaller/cheaper way to derive the 12v and 3.3v power rails. The EVM uses a lot of board space to do this (LM5010 SMPS for PVCC to 15v, LM2940 LDO for 15v to 12v, TLV1117 LDO for 12v to 3.3v).
• Look for a simpler/smaller/cheaper way to do the input buffer (that allows single-ended or differential input, and supplies the necessary differential input to the TPA chip).

But that's getting ahead of myself! At this point, I think I'm good on the layout, other than minor tweaks---unless somebody points out potential issues that I'm not aware of! I'm slowly working on a BOM and Mouser project. After getting some feedback, and finishing the BOM, I'll post the Kicad files as well as the bill-of-materials.

Thanks for looking and any feedback!

I have read the Yaqin MS-300B has global feed back.
The best I can see its by way of R16 in the attached...
Am I correct ?

For the Philips CD960, is the laser diode supposed to be on all the time or only when it plays a disc??

😕 😕
ckt

SOLD: Impasse preamp PCB (original) + transformers

Up for sale is the original Impasse preamp PCB from SY there are a few DN2540 already installed. I thought I would build it but have no time! So here its available!
I want to sell also the input transformers from Jensen JT-11P-1.

Price for all SOLD!
Shipping worldwide.

Item location EU.

I am curious as I have never used miniDSP.
My surround speakers in my Dolby Atmos theater are Dunlavy SM-1’s
I have built subwoofer enclosure’s with single downfiring Scanspeak 25w/8565-00 that’s the SM-1’s sit on top of.
I am using passive crossover on the Scanspeak woofers.
If I were to use miniDSP for ONLY the woofers would I have delay issues with my home theater setup?
I guess I should run my SM-1’s thru miniDSP as well so could help delay between the monitors and woofer , but would I have another delay problem being that that pair of speakers were the only ones that are fed via miniDSP.
Digital is all new to me.
Thank you in advance...

Hi,

In conventional 3 ways or more loudspeakers, best soundstages often result from a treble to medium being near a 1/2 wave length center to center spacing. Because the 1/4 wave length rule is impossible at those frequencies.

Now, Most of music is under 10K hz, there will be always few exceptions and instruments that climb high as piano or some instruments having very high harmonics that we still can perceive in the flow, but again all the story is often below 10 k Hz.

We often wan to cut-off outside the said area of ears sensibility as exposd in the Fletcher&Mundson curve. It translates by several approachs like hrned tweeter crossed below 1500 Hz, Full range from 4" to 2" sizes, conventional dome tweeters of 1.25" size, some ribbons and AMT of big size that handle for the hugest XO below 1k/1k5 Hz and of course all the horned compression drivers with possible low XO in home situation if the wife supports horn and have not fulled your suitcases yet because of that !

Now what happen with some design with very high cut-offs and more or less stiff slopes ? Say above 10K hz . For illustration like some design of ZU loudspeakers , some english style design like old Spendor or newer Harbeth with two differently sized tweeters and so on ???

I'm asking myself if I could not XO my ScanSpeak 2.5" 10F FR driver around 10 K hz or more with a first and second order slope 😕 Why not with some excelent tiny 3/4" Peereless, Monacor and numerous not so bad if excelent cars tweeters (Audax made some crazy good sounding ones with Fs around 6 k Hz for instance).

For the FR - full range- enthusiasts, a <300 hz to > 10 K hz standalone driver has certainly some appeal ! A logic behind it could be a size that makes the driver good enough for the task : not slam to perform below 300 hz (XO dependent of course) and not laser beaming treble as well (same XO dependent of course)

Trade offs discussion of course !🙂

I have a question when I am Looking at Amplifier Schematic, Channel 1&2 and the FET2 that cause of RED LED lighting.
The FET2 control by SD through a diode and resistor connected to a gate pin of the FET.
I understand the SD signal coming from the protection circuits is a value of a negative voltage.
My question is how does this voltage cause the FET to switch so that the RED LED
(Prot) turn on?
Is there a connection to the fact that the same SD signal is also connected through the diode and the resistor to the CD pin of IRS2092?

Thank you
Doron

Does anyone have 2 of the above to sell please?

Hi, I kindly ask if you can tell me the best RIAA inverse circuit, the most reliable, to make to do some tests on my tube phono preamp.

I would use it with a Analogic Wien frequency generator with 600ohm output and with a frequency generator of a USB oscilloscope whose output impedance I don't know.

Thanks a lot! 😀

Hi
I have read that later B225s had CDM 1 rather than the CDM 0. I want to buy one but want to make sure its got the CDM 0. Does anyone know the serial number at which the CDM 1 was introduced, or is there an easy way to tell without opening it up?

I would like to try a choke-loaded follower (6AS7G) to drive the grid of my zero-bias, 211, Class A2 amplifier.

The behavior of chokes in a plate circuit is widely discussed...due to inductive collapse, a choke is capable of voltage swings nearly 2x that of a resistor in the same position. But what if we use a very large (50 H) choke in a low-impedance environment such as the load for a cathode follower?

A resistive-loaded cathode follower generally has a gain of ~0.9 or so under normal conditions. What if a choke is present as the load instead of a resistor? Will the inductive collapse of the choke effectively raise the gain of the follower to ~1.8 instead of the usual ~0.9 - or does the inductive collapse not enter the picture in this situation?

Oh and BTW, the bottom of the choke will be returned not to ground, but to a negative supply so the follower can swing equally + and - about the zero-bias point. The DC bias current flowing through the choke is selected so that the follower output is at zero volts in the resting, no-signal state.

Thanks for any insights!

I recently made a 2-way bookshelf as an homage to the venerable LS3/5A. However, I implemented a crossover well above the usual 2.5kHz to 3.5kHz frequency normally used for 2 way speakers. I put the crossover at about 5.5kHz and used a modified inverted passive Harsch XO to achieve semi-transient perfect behavior and the resulting sound is so natural and great sounding. As the so-called “telephone” band that is so important is often described as frequencies from about 500Hz to 5kHz where most vocals, instruments, and soundstage spatial cues are contained in this frequency range. It would seem that the speaker I made might be called a Super Tweeter Assisted Fullrange Texhnology (STAFT) - the long lost brother of the FAST speaker. Some people like the WAW acronym vs FAST and mods have been going through all the threads and renaming them or adding WAW wherever they see FAST. So in that case, the acronym would be STAW or Super Tweeter Assisted Wideband (STAW). Whatever you like to call it, what I am noticing is that it produces a very natural lifelike sound with superb imaging and soundstage. So much so, I am building very special wooden cabinets for what was a foam core prototype.

Here is the measured frequency response showing the contributions from the woofer and the tweeter:


Here is the measured step response exhibiting a near right triangle shape indicative is a transient perfect speaker:


In this case, the woofer is really a wide bandwidth woofer capable of producing bass and mid range up to 5kHz and the tweeter is a conventional soft dome capable of crossing as low as 1.5kHz but I chose to do it at 5.5kHz. So the STAFT has the advantage of very nice highs and shimmer that many of us miss from a single cone fullrange driver. Even the some of the best and most highly regarded fullrange drivers like the Scanspeak 10F really only go up to about 16kHz. Whereas a true dome tweeter goes well above 20kHz. And the bass from a “midbass woofer”‘ is generally a lot better than the bass from a fullrange driver. So I suspect that this combo may just be the best of both worlds.

One other thing to note is that most natural sound sources like voice and instruments tend to lie either below or above the 5kHz to 7kHz range. Thus, the crossover doesn’t have to split the critical human voice or piano right in its most important (and audible) 1kHz to 3kHz region.

Here is the simple crossover:


And this is the speaker implemented in foamcore:


And a wooden version that will look something like this is being built:


I have been listening to this as a nearfield monitor for several weeks now and really enjoying the sound. I love the precision soundstage and imaging. I like how natural it sounds. I like the dynamics and the presence of high hats and cymbals. The upper end response of the RST28F-4 tweeter is remarkably clean for a $37 tweeter. I think what also contributes to how clean the tweeter sounds is the very high crossover so that the cone doesn’t move much and this doesn’t distort. The midbass is a low cost DC130A-8 treated paper cone. It was chosen for its deeper bass reach in a small sealed cabinet vs the more expensive RS150 or RS150P variants from Dayton.

This speaker also has a very benign electrical impedance curve:


Definitely never drops below 7ohms and averages closer to nominal 10 to 12ohms and so is perfect for most amplifiers to easily drive.

So the question is, would a STAFT generally play most music better than a FAST? Maybe it depends on if you really like the sizzle of a true tweeter.

We have of course see large 8in or bigger fullrange drivers with a super tweeter assist
But what I am calling for here is to pick a good wide band midbass or woofer rather than a fullrange driver. Perhaps the RS225-8 and an RST28F-4 in a waveguide with a high XO would be a similar type of thing? A modification of this system
Might produce another STAFT type speaker:
Passive XO for Time-Aligned RS225-8 and RS28F in Waveguide

Hi All,

I thought i'd document my current project, a hybrid centre speaker for my home theatre system. I'm currently building the above to compliment better my current left & right fronts, which are a no-baffle fullrange complimented with a TL sub and a horn loaded ribbon tweeter. The current centre is an old wharfdale devondale 3 lying on it's side. The wharfdale is great, but i think i can do better.

I'd decided on an open baffle mid (pioneer DSS9 midrange i'd had sitting about for years) and horn loaded ribbon (another pioneer unit), vertical layout, with a 12" bass on each side. I'm not yet convinced about sealed/open benefits of the bass drivers, though with a Qt of about 0.5, i could go either way, i'll cross that bridge later. Anyway, onto the mid and tweeter. Flush mounted onto a piece of hardwood, 1:1.61 offset, fired up REW and pulled out a linkwitz style mic and measured the midrange.



Oh dear. Listening, there was a distinctly gritty sound. Something was rattling around in the magnet gap. Undeterred, i unscrewed the 3 magnet fixing screws with polygrips, the old glue presented no issue and pop, off came the huge magnet.



Yep, crap in the gap. After a blow out with the compressor a good scrape with a bit of blunt stainless (from a windscreen wiper) then a final tweezering out, the gap was empty. The voice coil appeared to be edge wound, silver coloured (plated?) and wound on paper. The cone, vapour deposited coated titanium. Quite a bit of effort gone into this driver, worth saving.



Back together, re-aligned and re-measured and voila!



Now to deal with those nasty breakup modes...

I read that even order crossover that has good phasing will have a deep null when the polarity is reversed. Will this apply to odd order crossover? I have tried to sim a crossover for my project and when I reverse the polarity, instead of having a deep null, it rises up.

Also, in XSim, what is the difference between as derived and as measured? Which one should I use if I got the drivers data from tracing the manufacturer specs?

I attached the files that I use for my project. The .dxo is also in that file, maybe if someone want to help me to design a crossover? Thanks!

Hi,
I have the chance to buy one of these players quite cheaply. I have a strong recollection form somewhere that the 'Fine Arts' range was very highly regarded but I can't find find any specifics.

The one I'm referring to is the MT-100 and is a kind of gold/champagne colour. It looks about 3/4 width as if it came from a mini stack system.

Anybody heard one of these? Is the fine arts range similar to the Sony 'ES' range. i.e. is it a special flagship range?

Any help would be much appreciated.

Regards,
Martin 🙂

Edit: Just worked out it is actually an M-100 😀

Oops! My research may be more effective now.

Back to Google ..............................

I'm looking for a different amp to power my second set of speakers in another room. I currently use a Meridian 557 in my office which is my main listening room (yes, because I work too many hours) but it's not a place for listening with others. I've been using a Rotel RB-990BX to power the speakers in my family room which has space for lots of people but the 990 only has single ended inputs and doesn't match up to the Meridian 557 in sound quality. I'm thinking of getting either another Meridian 557 or perhaps a Rotel RB-1090.

Let me know if you have experience listening to both the Meridian 557 and the Rotel RB-1090 and how you feel the sound quality compares between these two amps.

Thanks!

Fostex FE108ES II Full Range Drivers. Special Japan only model. 4” $125 plus exact shipping.

Hey everyone. I haven't posted here in years. I know just enough to be dangerous. I just completed the first phase of restoring my Marantz 2CH (circa 2000-ish). This was one of my favourite amps because of it's simplicity, but lately I noticed the sound falling flat. It was never a Bryston but it was getting outright boring.



I upgraded components based on the Ver.2 upgrade parts manifest (attached) as well as some things that stood out to me:

- Replaced all electrolytics with Nichicon audio
- Instead of the Ver.2 spec 15000uF main caps, I used 10000uF caps like before, but placed a pair of 47uF Nichicon Muse caps closer to the transistors
- Replaced the secondary rectifier bridges with schottky 1A diodes
- Replaced the film caps with WIMA polypropylene 2.5%
- Replaced the main power traces with symmetrical 18GA copper
- Replaced the input/output wires with shielded copper
- Shielded the AC
- Removed the variable input



I can say now that I am a believer in basic stuff that some have called snake oil remedies. The difference is night and day! This amp sounds better than anything else I've heard out of Japan. Premium audio caps, schottky rectifiers, wire shielding, and trace fortifying make a huge difference when combined.

Phase II will be installing my USB 24/196 DAC directly into the case, eliminating the interconnects and yet more solder joints.

Out of this project many questions arose that I wonder if you could help me with. Don't bother writing a novel when a sentence will do:

1) If I put my ear against the left speaker with no inputs, I do hear a VERY faint 60hz hum. The right speaker is dead silent. When I play music it sounds crystal clear. Any ideas where to start looking? The Sanken transistors are original and have never been abused. The JRC2068DD op-amps are original as well. Those are the things that are great about this amp so I didn't touch them. Here is a top-down view and I've attached the PM8200 service man pages which have the same output stage.



2) I haven't tied the shielding down yet because the amp is ungrounded. Should I a) Tie them to the floating case? b) Install a grounded power cable just for the case/shielding or c) tie them to 0V?

3) Why do they put the rectifiers on the audio board? I understand that the caps need to be close to the transistors, but why not rectify the power and smooth it with one set of caps then send it over to the audio board and smooth the ripple with a second set of caps, thereby removing the AC current from the audio side? Two smaller caps are the same price or less than one cap of the same size anyway. I would have removed the bridges from the board already if the hum was coming from both speakers.

Thanks in advance and also thanks for all your inspiration!

Hello guys. I am totally new with diy sound but i want to try to make my first custom speaker.
I know i am trying something very difficult for 1st project but i want to give it a shot.
I want to make a central channel for home theater.
I want it to be MTM style and particularly
woofer-midwoofer-tweeter-midwoofer-woofer. It will be a 3-way system.
I will use one tweeter: Monacor DT-28N 1-1/8" Dome Tweeter With Waveguide
two midwoofers: Dayton Audio RS125T-8 5" Reference Woofer Truncated Frame
2 woofers: Dayton Audio DC160-8 6-1/2" Classic Woofer (i would prefer to go with the reference but i cant find it in stock)
The crossover points i will use are 375Hz-3000Hz (or maybe i will change it to 3500Hz to be more safe for the fs).
I have designed a crossover in xsim but there is a range where the impendance drops a little below 4 ohms and i am afraid for my amplifier.
Is it going to be a problem? I haven denon 2700h.
I attach some photos of the system in xsim (2 possibilities).
Do you have any advice?
For the drivers or the crossover? Should i change something?
I want to have something to start with and then i will improve it.
Thank you!