Sold.

Up for sale is an Iron Pre Single-Ended Essentials kit. This is the early-release version as shown in the photo. The parts bag has been verified complete, and the kit includes two Cinemag CMOQ-4HPC, main board and a twister board. $160 USD + shipping. I prefer to use Paypal F&F since we are all friends here at diyaudio. Will ship double boxed. US/Canada only, please. Thanks!

This is a builders thread for the "long and skinny" J2 clone boards.

Please post hints, tips, discoveries, etc. And of course pictures. 🙂

I picked up this amp (Alpine T707)and all of the outputs are missing. Does anyone have this information? Or a service manual. Any help would be greatly appreciated.

For sale a pair of tweeters
220 euro plus shipping.
i am in greeece so europe
would be easie for shipping.

I need a new preamp, and I want to to build a DIY preamp like Mike Freda did. Have collected parts like output transformers from Edcor, tubes...Trying to buy the HLMP-6000 LED, for the ccs, but it is difficult to obtain. Are there any equivalents to the HLMP-6000? Data for the LED are 1,6v and 10 mA. Kan I use any other LED, but with the same data?

Login to view embedded media

I would like to explain my novel compensation I used lately in all may amps, CFA or VFA with excellent result.
This is a kind of TPC (Two Pole Compensation) but in my opinion much improved with excellent bandwidth Phase Margin (PM) and Gain Margin (GM).
To start with is simple TPC. Choose components give good result but not good enough.


Second step is improved TPC by adding a capacitor parallel to VAS emitter resistor. With the simulation I selected the capacitor value to get good LG (Loop Gain) plot.
Both PM and GM are improved.


Third set is splitting input leg capacitor and connect half in input leg coming from VAS and half directly from output. By simulation choose values could be different to get best compensation. PM and GM increased enormously.


Fourth step is to get it even better decreasing TPC resistor (R1), ULGF decreased to acceptable value.

I hope this can help if someone decided to use this kind of amp compensation.
Intentionally I did not use any math, as TPC calculation was showed before even in this forum. Sorry for my simple common language.
Damir

This is very simple amp, enhanced VAS was not used, with more elaborated amp the result is even better (higher Loop Gain an so on).

As suggested by Zen Mod, I have opened a new thread for discussing logic solutions to replace the original rotary switch and the plain volume pot.

Whether you want to control the relays remotely (Lazy Boyz) or from the front panel using Arduino, ATtiny, ESP32, or any other MCU, this is where to discuss it and ask questions.

Attenuators, whether it's remotely controlled or not, can also be discussed here. In fact, any deviation from the standard rotary input channel switch and/or the standard pot qualifies for discussion here.


Links to important information

The original Iron Pre threads:
https://www.diyaudio.com/community/threads/iron-pre-essentials-kits-for-the-diya-store-register-your-interest.390509
https://www.diyaudio.com/community/threads/whats-wrong-with-the-kiss-boy.293169/

Updated schematics and BOM of the Iron Pre kits: post #1 of the Iron Pre Essentials Kits thread

Modification of current boards (first batch) to allow switching of the relays via microcontroller.
SE version: Post Post #13
BAL version: Post Post #14

There is some valuable information about driving the relays using logic pins on MCU's in the Iron Pre Essentials Kits thread, starting with post #1,232 and maybe even before that.

PS: This post will be updated regularly to include important information.

Sorry for a very long first post but I hope it gives all the relevant information needed without having to drip feed it.

TLDR; player won’t read CDs after being stored in attic for about 20 years; I changed all electrolytic capacitors, and resoldered most joints, on the power, decoder and servo boards. Player will now read TOC of a couple of discs sometimes but no others. It won’t play any tracks or discs.

A few months ago I decided to get my late 1980s B&O system from the attic where it had been stored for about 20 years and set it up in a spare room. Unfortunately the time spent in the attic has been detrimental to its health.

The CD player wouldn’t read disks properly giving a “?” on the display.

I’ve done a number of things to try to fix it based on the advice I’ve found on the internet.

I changed the electrolytic capacitors on the 5886 servo board with the recommended pack from BeoParts including the all-important blue axial one. After that it played for a couple of minutes but then powered down. I then resoldered the voltage regulator connections on the decoder board. Success I thought as it now played CDs. To check it out I left it on repeat play for a few hours just to make sure I’d fixed it and it worked fine. But, the next day it wouldn’t read disks at all again.

Since then I’ve;

changed the voltage regulators on the decoder board in case they were performing below spec

checked the caps on the power board. I did find a faulty one although that didn’t actually relate to CD playback. It’s one that’s controls the remote controlled standby system. But, I changed them all just in case.

changed all the caps on the decoder board. I first changed the ones relating to power despite none showing as faulty. I measured the DC voltage getting to the servo board from the decoder board and it is close to specification, but not perfect. The two feeds that should be + and - 10v are between 11v and 12v (taking into account if they’re + or -). The other power feeds should be -6v and +5v; I’m reading about + and - 6v on both. Do these numbers look OK?

Still no joy, so I checked and changed all the remaining capacitors, both radial and blue axial, on the decoder board. Am I right in thinking they relate to sound processing? All the Philips blue axial ones were out of spec, so not a wasted effort.

After all that, I now have a player that occasionally reads the TOC on a couple of CDs correctly as it shows number of tracks, CD total length, track length and lets me advance to individual tracks. But it won’t play an tracks. If it tries to play them it shuts down after a few seconds. Other CDs it just shuts down before it can read the TOC.

Finally, when I listen to it trying to play a CD I’m sure the speed the CD rotates at seems to change as though it’s hunting for the correct speed and then it shuts down. There is also a sound of something rubbing when the CD turns, but there is no evidence on a CD as to where it might be rubbing.

Apart from messing about with the laser power potentiometer, which I’m not keen to do as all I have is a standard multimeter, I’ve run out of ideas so am looking for any guidance you guys can give me. Do I need to test/replace the other components on the servo board; ceramic capacitors, diodes and transistors? Or, is it drive motor related? Or, maybe find a non B&O working player with a CDM 2/10 drive and try that in my B&O?

The top end on some drivers drives me nuts. Jordan JX92s/Eikona, 1st gen Alpair 10/6 i found quite fatiguing. The second gen Markaudio 7.3/10.2 were greatly improved, A10.2 still having a bit of edge. Alpair 10.3 got even closer to the A7.3.

Note that the Markaudio drivers were fully EnABLed.

This is about my annoyance with the top of the Alpair 11ms. And to a lessor extent the A7ms.

Taking into consideration the many complaints and measurements on the Alpair 10.3 of some significant issues up top. Something i did not hear in the A10.3eN (they did have a bit of edge that went away with many hours). @waxx @wchang

There have been comments about the edge on the A7/11ms by at least a few members.

So i thot it would be worthwhile to try the simple mod lifted from EnABL that was most likely the cause of the ringing. So i did the penultimate step of the EnABL treatment, 2 coats of acrylic gloss (diluted 50%) on the cone and one on the dustcap. Sort of analogous to a dirt cheap MAOP but instead of electoning the topfew molecules of the cone, we add a layer many molecules think on top. The purpose of what i have is to paint over decals on model planes/trains/cars.



it is difficult, but possible, to reverse the mod.

Bernie put them in these Compact Floorstander Mar-Ken11ms. These are high quality solid wood build like the Sibelius.



I had heard these stock (and also his Pensil/A11ms & FH3/A7ms builds). When they came back with these drivers installed it wasn’t very long before i thot i had something. A month+ in they have not driven me up the wall.

But i’d like to see if some members would be brave enuff to try it on their drivers. And some who have measured and added notches, does it obviate (or reduce the magnitude) of the notch.

A10.3, A7/11ms in particular but if is working, probably on things like the little Founteks too.

Not great light, but some alround shots.



Questions? Volunteers?

dave

@hobbers

I open up this thread today because on the MPP thread we start to see modifications and subjective impressions of the beta builders. A lot more people will start to build the Parradise R3 soon and this may lead to confusion of what is the "official" version and what to shoot for. I have personally no problem when somebody wants to make a change and does like the change better. It`s your equipment and your music.
What i do like to happen is that a minimum of problems show up when people build the circuit as is. They have paid for and they should get the promised result with not too much frustration.
That should not distract from experimentation. When we find flaws in the original circuit or we can improve the performance there is a chance that someday an R4 version ( make that R5, 4 is an unlucky number in parts of Asia ) sees the light of day. It is my desire though that this kind of adventures should happen on this new thread. Than we we can clean up the MPP thread and make it more digestible for new contributors. That does not say that anybody polluted the thread, quite the contrary. It was and is moderated excellent by Salas and crew. I look on my own fingers as we say in Germany and i got many PM´s and such of people complaining that they lost the overview. It is a complex and fuzzy busyness for sure. that should be improved. Have fun.....

One each AD1862 & AD1865 both with brand new N-J grade chips.

Both boards have header pins inserted for separate supply to op-amps. I recommend using dupont 2.54mm single pin female prototyping leads.

The DACs will need an I2S input module, either Amanero type or XMOS. It is worth trying the new York Pico by Eclipse as discussed in the vendors forum, this looks a very good design. For sale now on Tindie.

AD1862N-J completed DAC - SOLD

AD1865N-J + OPA604 op-amps completed DAC- £65 plus shipping

Payment with Paypal friends or add fees.



Also for sale are DAC boards with shift registers mounted, included are DAC and op-amp sockets. AD1865 board comes with tube IV PCBs and SOIC to DIP adapter board for mounting DAC chips

AD1862 DAC boards with shift registers - £10 each

AD1865 DAC board with shift registers plus tube IV PCB kit & tube holder - £15

Hello from Hannover/ Germany. Looking forward for interesting information regarding DIY Audio.

Hello everyone...greetings from Malaysia...My Name is Hafiz...just call me hafiz...i own front loading turntable Aiwa AP D50 and still searching info to restore it back to fully function...i hope i can gather all info and sharing here...best regards

Hey, my name is Raanan. I haven't built any speaker yet. I am new to this hobby and very exited about it. I am working on building a clone of the Orangutan O\93. I also want to upgrade my center speaker, and I am still wondering if it would be better to buy new SVS Ultra center or to build my own center.

I've restored an Aiwa AP-D50 turntable and have even sourced a replacement end sensor. Everything runs perfectly (the usual fault of the tray not ejecting unless pulled) but one very annoying fault that I haven't been able to fix is that the tonearm lifts and returns to the rest. Sometimes as soon as the stylus drops sometimes towards the end of the last track, sometimes halfway through the first track. Occasionally it will play through without happening. I've studied the manual and schematics. Can anyone offer advice?
Could S3 the load play/cut switch be ghost triggering? I've cleaned it with deoxit. If I turn the switch to manual the fault still occurs. I've spent a long time on this restoration and this final fault is driving me crazy.

On pins 4 and 5 of the ADAU1467 there is an input and output of SPDIF and I would like to use them in my own preamp project by installing Toslink or RCA or preferably both, could someone show a basic diagram of such an interface?? I've been looking everywhere and somehow I haven't found it anywhere :-(

bonjour quelqu’un peut m’expliquer comment fonctionne ce filtre bass 12 db mid 6 db high 6db

As the title says this is module will keep the output of your preamp shorted to gnd with the condition this output is ac coupled.

Remember for when used for turn on thump protection! if you power off and don`t wait that the relay disengages and power on again you will get the power on thump or if the network drops and suddenly comes back then turn on thump can be present. It is more a protection for our bad memory.. 🙂)

It can be used for turn on or turn off thump.
It can be used up to 36vdc(probably more) and when assembled should look like in the image below.



One module can be used for 2 channels in a stereo setup if same power supply powers both channels. If you have a dual mono setup then one module goes for each channel.

To use it is simple, connect IN to the output of your preamp that has the turn on/off thump, gnd goes to gnd of your pre and V+ goes to V+ of your pre.

I have attached the schematic, bom and gerbers.


Edit.
Thanks to JP for his suggestion! I made a r1 version that includes this diode and updated all the files.

Later edit: Because of the added diode the cap that does the turn on delay discharges more quickly and if you turn off and back on(or when network power is lost) most probably you won`t get the turn on thump. JP is an amp saver this time 🙂 so thanks again 🙂

I was digging through my stuff recently and I found a few Dayton Epique 5 1/2" drivers and wanted to do something fun with them. I was thinking of pairing them with some sort of bending wave speaker so it would have really big sound in a small package. Could I get a recommendation on speaker selection? It seems tectonic and Dayton are the only acts in town for BMRs, and I think the manger transducer is a bit outside my price range. I was also thinking of maybe an exciter on some sort of planar substrate, but I would imagine that would be slightly more engineering intensive to implement. This will most likely be an active configuration with DSP.

Assembled

Modulus-86 10th Anniversary Edition​

299USD$ or 400CAD$

hi all, here I am starting my journey into diy for improving my hi-fi system.
looking forward to engage on streamer/dac stuff and will be starting a new Ian Canada streamer/dac build soon.

Hello, I am a big fan of DIY audio, and am trying my best to build a great sound system for relatively cheap, with decent used equipment.

I have 2@ B&W 604 S2 speakers,
fed by 2@ NAD 218 THX amplifiers in mono-block mode/vertical bi-amped to the speakers' passive crossovers, 1 amp for each speaker,
fed by a Marantz SR7011 pre-amplifier in Stereo mode.

It was all working nicely, until my kid pulled out the Mini-RCA input cable from my iPod to the Marantz amp. That made the dreaded big POP noise; after that, both midrange tweeters are entirely dead. No scratching or humming, just 0 midrange. It sounds like the high tweeters and the low woofers are working, but at this point, I'd like to somehow test all woofers/tweeters on both speakers and each speaker's internal crossover, to make sure it's all working. Since the problem is on both speakers, I can't tell whether it's a 2-speaker problem, or my amp/s has a problem. I have basic electronics knowledge and am very willing to learn. I have documentation for each component, if anyone needs me to upload them.

Is it the speakers, the woofers, the crossovers? or both power amps? or the Marantz pre-amp? How do I test, how do I proceeed, what do I do, where do I start?
I have several NAD 214 amps, that I can use instead of the 218's, to test if it's the 218 power amps. My fear is that the POP killed something in the Marantz pre-amp.

For later:
-I have collected 6@ NAD 214 amplifiers, which I will assign 1 amp in mono-mode to each surround sound channel for a 5.2.4 Atmos setup. I have all the speakers, subs, amps, I just never set it all up. The 2@ NAD 218 THX will remain in mono for the front 2 channels. I know that is overdoing it. I wanted to make an all mono-amp setup for fun, for relatively cheap.
-I'm not sure if there's a way to make the SR7011 mono-amp its 9 amp channels into 1 amp channel full force; I was hoping to use 1 mono channel for Center channel, but I can't tell from reading the manual if there is a way to make it work in mono-mode at 125 watts RMS.
-Subwoofer is 2@ B&W ASW610XP. I quite like them.
-I have 5@ ButtKicker LFE for the 5 seats for watching movies, and 5@ old Crown amps to power 1 to each ButtKicker; they want 1,500 Watts RMS each.
-Just for fun, I no longer measure my Franken-stereo in watts, but in horsepower. As of today, we are at 9,675 watts RMS = 13HP. Huzzah! 3/4 of the total HP goes to the ButtKickers, so it doesn't really count towards the sound system.

For those of us that don't have access to an Audio Precision set, what are folks out there doing for measuring THD, IMD, SID, whatever? Anything clever for helping to set bias points or actually measuring impacts of changing ground connections, etc?

Here are some excerpts on the topic from another thread ( the Leach amp design thread, I beleive); comments welcome (hint, hint!):

From Damon:

...As for other designs and tweaks, I can only point to Doug Self
and Randy Sloan and their books on amplifier design for hints
as to what might be possible. But we're already into a range of
low distortion that my geriatric collection of Heathkit test
equipment can't possibly measure, and I can't afford an Audio
Precision test set.

Unless I can come up with a "cheap" Audio Precision equivalent,
I'd be shooting completely in the dark with new designs. And
that's daunting....

From me (mlloyd1):

..... I wrestle with the same problem as far as distortion measurements. I usually look at distortion waveforms on my scope. I think we need a group discussion about how to work around this issue for DIYers. There was a REALLY nice project in Audio magazine (RIP) some years ago for a very serious analyzer that could be reworked with current tech (using OPA604 op amps and current buffers instead of TL071, for example) and probably have much more performance than we would need. I've also seen some writings in past issues of The Audio Amateur (now Audio Electronics) by Erno Borbely ( I think) for a distortion analyzer. There was a project in Radio Electronics some years back also. I actually made a PCB and partly built this one. In my opinion, it worked very well - it gave consistent measurements with a Audio Precision I had access to at the time. However, it was VERY tough to control the electronical noise in my DIY environment though - halogen lights, misc dimmers, hair dryers, etc. (it's tough being a married DIYer!) don't make for a clean test environment. Finally, reading through the service manual for some of the HP distortion analyzers (I think the guy that did the Audio magazine project referred to doding this also) suggest a few ideas as well. Alas, I can't seem to find my copies of this anymore :-( I can't recommend enough times that service manuals from GOOD test equipment makers like HP and Tek are EXCELLENT sources of material for study!

I'd be happy with a distortion test box that could spot check with high resolution at about 4 frequencies: 50Hz, 1KHz, 20KHz, 75KHz.

Who's game?

Nelson, what do you do when you have something to test (say an idea at home late at night) and the Audio Precision is nowhere around? Wait until later? 🙂

Maybe we could even ask an analog Guru like Jim Williams at Linear Technology to design a simple, high peformance THD analyzer circuit (I single him out because I remember and oscillator circuit he designed that was claimed to have THD specs in the single digit parts per million. This is incredible!). They might already have such a design sitting around somewhere; I haven't checked their web site and app notes lately. Hmmmmm ....

from Grey:
.... Give the distortion analyzer project its own thread so people will be able to find it more easily.

I'm interested.

I'd like to reiterate--for those who haven't understood what I've said on these matters--that I'm not against low distortion, per se, just the use of massive quantities of negative feedback to achieve the distortion figures. Just don't pursue low distortion as an end in itself, as you'll usually find that once you reach a certain point sound quality suffers. But up to that point it can be a useful tool....

Hi. I am an electronic engineer and audio enthusiast. I love to squeeze more out of devices, modify and improve devices. I am constantly improving and trying to move with the times. Every first step can be the beginning of an exciting journey. Who knows what I can do tomorrow?

For sale a pair of scanspeak passive radiators.

They work well, but I going for a different approach. They are currently in use.

Price is 200 for the pair plus shipping costs

I am in Greece 🇬🇷

Happy to ship world wide

Up for sale an excellent high end signal processor from Helix. It is the Helix dsp PRO mk2 upgraded by the Amp Doctor english / Gordon Taylor (designers Genesis UK). Excellent sound quality and tons of parameters. The Helix dsp usb module is included and a programmable controller is also included (I use it for master volume and sub volume, also switch between two savefiles )

Price is 800 euros shipped within EU

I am starting a new project to assemble an amp that will use two LM1875 TO220 packages in a small, lightweight board. The large heatsink I have is more than adequate for thermal dissipation for the amp, but it is not drilled and I don't have the tools for drilling and tapping to be able to screw the LM1875s to the sinks.

I see thermally conductive adhesive glues and even adhesive tape advertised. If I supported the weight of the boards in the case with standoffs, would the thermal adhesives do the job of conducting heat effectively to the sinks?

thanks!

was fooled when purchasing this Yamaha CA 1000, the two internal metal covers are missing, I'm looking for help, thank you

Hi everyone, newbie here!

I play the Cavaquinho, a sibling of the Ukulele that uses steel strings and has a bright sound. We use piezo transducers to pick up the sound, normally two small discs underneath the instrument's top board.

It works well, but it has a high impedance, and we need to put a lot of gain in the mixer. So I would like to make an all-in-one pedal to make it better. The chain would be something like this:



The Digital Tuner is something I worry about later.

For the Preamp with tone controls, I thought about using one described by Rod Elliot at https://sound-au.com/project202.htm



Then I need to create the boost and DI box output. Can I use the OPA2134 to achieve this as well (I bought 5 of them)? I would like to power this either using a 9V battery or a rechargeable 18350 lithium battery.

Is my project feasible? Am I missing something?

Cheers!

I'm looking at fixing my Akai Am-A70, problem is the relay keeps going on on off randomly,

Power supply voltages seem to line up with the schematic

+/- 54vdc
+/- 16vdc
+ 12vdc

Offset at emitters on one channel under 10mv the other 100mv, no adjustments that I can see

Where to start from here?

Long time amateur speaker builder here, retired and having fun. My last project was these ported 3-ways, very successful and running right now. I promised a friend I'd build him a fairly compact system, so this will be my usual 2 way but with electronic crossover and bi-amped. Here's the component list:

PRV Audio 15W1000v2 15" Professional Woofer 8 Ohm
PRV Audio D260My-B 1" Mylar Horn Compression Driver 8 Ohm
JBL Selenium HC23-25 1" Exponential Horn 100x40
Extron XPA 1002 Power Amplifiers
Behringer SUPER-X PRO CX3400 High-Precision Stereo 2-Way/3-Way Crossover

I'm using three of the Extron amps, I found a very favorable review and decided to try them. I have one in stereo for the highs (60w/ch), and one each for the lows, bridged (200w/ch). These are Class D, but the tech seems to have reached a point where that is practical. Definitely a different sound than the tubes I prefer, but very clean.

I'll be using 3cu ft enclosures, undecided whether sealed or ported. Comments and calculations welcome!

Hello,

I would really like to build a 100+ watt Exicon ECX10N20 & ECX10P20 or Exicon ECW20N20 & ECW20P20 Lateral Mosfet based amplifier.

Existing examples that I can find,

->From the Build Audio Amps web site, Project #5,

Project #5 100W MOSFET Audio Power Amplifier

But is uses Hitachi 2SA872, 2SB647 and 2SD667 transistors that are no longer available

->Pee Cee Bee's V4 lateral mosfet amplifier,

PeeCeeBee V4 Rev2

But it only uses one pair of output transistors for 50 watts.

->SusyJ has her 50 and 100 watt version of the AEM6000 lateral mosfet amplifier,

Susy J 50/100 watt version of AEM6000 amplifier

But is uses the SST404 which I cannot find anymore. I would also prefer through hole to all SMD.

->Apex FX-12 lateral mosfet amplifier,

Apex FX-12 gerbers by Prasi

Only one pair for 50 watts.

(BTW, has anyone done a BOM for dummies for the APEX FX-12)

-> Elliott Sound Products Project 101

ESP Project 101

This one actually has most of what I am looking for, except Rod is half way around the world and having purchased from him in the past, post from Australia is ssllooww.... I would prefer to be able to have double sided boards made without jumper wires.

Is there a published two(+) pair lateral mosfet amplifier with an easily source-able parts list?

Don't necessarily need gerbers, a PDF of the circuit board would be fine.

Plan B will be ordering ESP Project 101 boards...

Thank you,

David.

Study of using Fourier transforms to implement digital servo control in XANADU based systems.

This is a test thread, please do not reply (even though you know you want to 😉)

This thread is for discussions about the diyAudio F5 Build Guide we have created for the First Watt F5 Amplifier by Nelson Pass. For more information on the boards available from the diyAudio Store, please see the information below.

Please note: The V2 and V3 boards have different parts placements.

• New V3 build guide here: Firstwatt F5 amplifier v3 - diyAudio Guides
• Old V2 build guide here: diyAudio F5 Build Guide
• Product Page
• Store support area thread for discussion the boards themselves specifically
• Schematic
• Bill of Materials
• Dimensions

Threads on diyAudio that relate to this product (If we have missed one, please post it in this thread and we will add it to the list):

• Build Thread: http://www.diyaudio.com/forums/pass-labs/121228-f5-power-amplifier.html
• Build Thread: http://www.diyaudio.com/forums/pass-labs/182723-how-build-f5.html
• Build Thread: http://www.diyaudio.com/forums/pass-labs/188691-illustrated-guide-building-f5.html
• Build Thread: http://www.diyaudio.com/forums/pass-labs/185154-initial-setting-f5-bias-help-please.html
• Listening Impressions: http://www.diyaudio.com/forums/pass-labs/155599-f5-listening-impressions-discussion.html
• Modifications: http://www.diyaudio.com/forums/pass...building-quartet-amps-search-ultimate-f5.html
• Modifications: http://www.diyaudio.com/forums/pass-labs/168040-f5-2sk2013-2sj313.html
• Modifications: http://www.diyaudio.com/forums/pass-labs/182966-f5-low-z-loads.html
• Review: 6moons.com - industry features: Swansong for an ugly duckling

All drivers very bought few months ago, so they are new.
NE225W-04, new, not measured, not soldered, not mounted. 1 unit only. 100Eur
18W/4434, not soldered, mounted, measured. 100Eur a pair

EU shipments only
petr.kocourek@gmail.com

Just recently signed up to this forum to hopefully get some pointers in upgrading a Creek OBH-11 headphone amp i just bought. It's working just find but i've seen that there are some upgrades that can be done so i'm now interested in trying this.

The original TDA7293 is sold for $10 from mainstream vendors. 2 years ago when I looked last, they had ST logo unable to distinguish a copy from original but defective. Nowadays I see without logo with Hugh quantity availed for $1 to be sure they aren't defective original ones.
I ordered 2 pairs from 2 vendors to see what they worth but I will receive them in 1½ months.
These boards sold for $3, certainly are functioning but with what quality?
On youtube, I find several audio tests but they are with simple music mostly Indian as this compared to probably copy LM3886.

Login to view embedded media

Hello Brainstrust,

Been a long time audio/music lover since I was a kid thanks to my dad and his love of music.
My first taste of Hifi was from a 1976 Joergen amplifier, turntable, tuner and a Teac tape deck running into Joergen speakers, I think it was that combo that kicked off the bug.
Fast forward 50 years (ouch) and the passion has not dwindled, my current set up has been through many iterations and plenty of poor decisions and wasted money although I'm not alone that journey in sure.
So why am I here, well I've decided that I want to put together a small second system and given that I now have more free time, I'm keen to explore the world of diyaudio so that I can not only appreciate the end result, but take some pride in the fact that I built it myself (even though I'm leveraging somebody else's design and skill) but that will help me learn along the way and keep the brain engaged.
What do I want to build.... Everything.
I have been scouring the interweb and YT looking at various designs and options but have arrived at the point of decision paralysis.
I started with tube amp kits, then rPi options and also SS kits, I feel the pi option is quick and easy and the results are quite good, so I might go down that route for streaming (can also integrate the dac with this option).
Speakers are the tricky one from my perspective as designing crossovers will be a completely new science and learning curve.
My background is electrical and Instrumentation trades, so pretty comfortable with the technical and build side of things, just need to smarten myself up in the electronics world.
Anyway enough waffle from me, I came here to learn and seek advice from the diy experts and have some fun along the way, I look forward to interacting with you in this forum.

Cheers

Jason

Hello, does anyone have any experience with a Dayton HTA200? thinking about buying one for a spare room. Wondering if they are worth it or just novelty junk? Thanks!

For sale near me. Interesting?


Regards,
Dan

Hi everyone! This is my first post, I am quite a newbie in electronics, so please forgive my ignorance.

My idea is to make a headphone amplifier that takes one balanced mono input and delivers one unbalanced output. But I want to make 8 of these and put them in parallel! Here is the sketch:


I would be used to drive in-ear monitors, each musician has a bodypack with a passive volume control and a 3.5mm jack to plug their headphones, something like the Behringer PM1.

The input comes from my Behringer XR18 auxiliary outputs, they are mono and balanced, here are the specs:


The output also is mono but unbalanced. The headphones used for in-ear monitoring are normally 32 ohms.

Ah, I forgot to mention: I want to make it as cheap as it can be 🤑 , but it would be great to have a clear sound with little or no noise.

So, what do you suggest?

Many thanks!

I have a pair of unused Faital Pro 8PR155-8 Midrange drivers for sale. $100 for the pair, includes shipping to US (no Alaska, Hawaii sorry). I don't have the original boxes. The drivers will be boxed appropriately for shipping. Shipping will be USPS Flatrate.

I have B&O CD-50 which would not eject, I've replaced the rubber band that drives the tray cogs which has fixed the tray - discs now load.

Disc however will not play - I can hear a clicking sound coming from the mechanism that hoses the laser and motor. Eventually the disc is ejected.

Does anyone have knowledge of how the disc loading works? I can see that when the door is closed an arm below the disc lifts the disc up, before dropping slightly. I'm not sure if the disc should be picked up off the tray to be spun - if it should be I can't figure what keeps it off the tray?

Thanks.

I have purchased 3 T34Bs for left, center, right speakers (music primary) and need to move towards the next purchase.

I have been perseverating for months now. Almost purchased 3 x Bliesma M142A's, but I wondered if a 3-way might be biting off more than I can chew. Also, it seems that it would best match the T34 without a waveguide(?). This lead to lots of consideration of WG or not, power response, etc., more paralysis by analysis.

Room is well-treated acoustically.

I am picturing a wide baffle with large roundovers (a lot like the Grimm speakers). Would try and model with passive crossover, but unless very successful would move towards DSP.

Simulating an ~ 21" baffle in Vituixcad suggests full baffle support down to ~ 250 Hz. So at an approximate 1.3Khz XO in a two way, both drivers will be radiating into 2pi space, so measurements of dispersion in an IB (hificompass) should largely match what I will see(?).

@mabat 's waveguide, as an example, looks to be 120 degrees in dispersion, so would need a midwoofer to hand off to that smoothly.

Any thoughts? Thank you,

Bill

I have a pair of Hammond Choke 195J10 10mH 10 Amps DC for sale. Mouser has them listed for $91 each
Asking $100 for the pair.
They weigh 6.5 pounds each. I can ship priority mail flat rate, price depends on your location, Los Angles is $26.30.
W3.5" x D3.75" x H3.13"
Slight surface rust from sitting on my shelf.

Hi all,

I just want input for this Xiang Sheng 728A I want to mods it
This amp using 12AT7×2pcs, 12AU7×2pcs, 6Z4×2pcs
My questions should I change

• Tube to brand telfunken / mullard or any suggestions
• Upgrading Capacitor? Which one I should upgrade

tks

Hello friends, greeting you again. I am trying to repair another DD DM1000A that came into my hands. This time the amplifier arrived with damaged IC irs2092s, the entire output stage was removed to check output mosfets and necessary voltages in the IC, only the IC was changed and it began to pulsate. Now the problem is that the output fets which are Irfb52n15d get too hot and there is a working frequency of 345khz, I don't know if the frequency is high, I checked resistors near the IC and everything is fine, I have audio at the output and a current consumption of 1.75 amps, what else can I do to prevent the output mosfets from getting so hot?

Hi there, I am retired... and into Hi-Fi components, especially speakers.

I have picked up a matched pair of Infinity EMIT k planar ribbon tweeters, and a fairy closely matched pair of a/d/s Braun 206-0210 dome Mids. All are clean and in good working shape.

I would like to know if anyone here has combined these two types of drivers into an open baffle designed loudspeaker ~ that would either use a sealed box or open baffle woofer scenario.

I love how both these drivers sound in their particular applications, but that doesn't mean they will sound good together.

Any suggestions, thoughts, comments, amusing anecdotes... warnings, etc.?

Tone controls are the bane of true audiophiles, or so they say. And if truth be told, there's some real justification for that sentiment. Most traditional tone controls are based on the Baxandall circuit, which in my opinion leaves much to be desired as far as sound quality goes. I've never heard an implementation of that type of tone control that didn't seem to muck up the sound in some way that made things worse. And considering the way the phase and frequency response are treated, and with the inter-channel variation caused by crappy-cheap potentiometers performing thier special kind of "magic", it's no wonder most prefere no tone controls at all.

But inspite of all that, I've always felt the need to have some way of correcting the response aberrations that are almost inevitable given the fact that the recording artist and/or engineer has no way of knowing what the environment that the recording is being played back in will be like. So I've put together a circuit that I believe is functional and good sounding while avoiding the pifalls and shortcomings of the usual designs.

First, the range of adjustment is limited to +/- 7.5dB using 1.5dB switched steps, I can't think of any reason why anyone would need the 15 to 20 dB boost or cut that most controls provide. Using rotary switches instead of pots also avoids the inter-channel variation thing, and allows using a center position to ground to completely disable the tone control action when it's not needed.
Second, instead of the usual 1kHz center point, I've put this one around the mid-600Hz range, which is actually the middle of the audible range of the Human ear.
Third, the slopes are shallower, which makes the adjustments much more subtle but still effective, and also causes less phase shift. There's also a provision for adjusting the turnover frequencies if desired. The final result is a tone control that is usable and won't cause more problems than it solves.

Below are the frequency response plots, schematic and bill of materials.



View attachment Tone Control BOM.txt

Mike

A friend of mine at the time bought this full range speakers from me. Since I no longer have any contact with them and no longer have the supplier catalog where I ordered the speakers 1976, I can't find out the model No.

The driver looks similar to those from the first both attached image, but instead a cloth surround was a foam surround in use (for better results in the low frequency area in small cabinets).
The logo on the magnet of my old version was the same as to see on the other attached images.

Who know the model naming of this vintage full range driver ?
Thank you very much for an advice.

P.S.: in the attached data sheets from various models in 1985 the wanted model was no longer listed.
The German supplier on those days was Oppermann Elektronik.

Currently address and web-address:

S.I.P.E. S.r.l.
Società Ingegneristica Prodotti Elettronici
Via Alioli e Sassi, 24 - 21026 - Gavirate (VA)
Tel: +39.0332.746464
Fax: +39.0332.744473
E-mail: info@sipesrl.it
https://www.sipesrl.it

under
https://web.archive.org/web/20031201000000*/www.sipesrl.it
are no archived information to find
and under
https://www.ufficiocamerale.it/2750...tica-prodotti-elettronici-srl-in-liquidazione
I read this:
DATI DELLA SOCIETÀ - S.I.P.E. SOCIETA' INGEGNERISTICA PRODOTTI ELETTRONICI - S.R.L. - IN LIQUIDAZIONE
Indirizzo: VIA ALIOLI E SASSI 24 - 21026 - GAVIRATE (VA)
Rea: 233826
PEC: sipesrl@certimprese.it

I have no problems utilizing equalizer APO/peace GUI with the computer as the source......to one or one pair of speakers only

What I would like to do with my current set up: (please let me know if this is possible.....so far I have failed.....also let me know if there is a work around......don't mind buying another low cost preamp and/or DAC if necessary)

TV as the source.....in this one room, I enjoy utilizing the TV as the source as I do a lot of over the air antenna TV watching (uncompressed video and audio) and like the TV Spotify interface......and watch a lot of Blu Ray movies (Blu Ray player to TV with HDMI)

With my current set up I have the TV going to an amplifier with High pass and full range out. The high pass goes to a pair of DIY exciter panels. The full range out is split to a subwoofer amp with low pass for the subwoofer and the other split off RCA full range goes to another amplifier to drive a DIY mono full range center speaker.

I would like to place the computer (in line) in front of the amplifier that drives the DIY mono full range center speaker......to room correct that speaker with a PEQdb filter uploaded to APO equalizer on the computer to filter and room correct that center speaker only.

Is this possible?
Thank you.

can someone advice me on how to calibrate the bios - trim on these amplifier boards .

I have built the the amplifier into separate chassis all is working but they are pretty much stone cold unless they are driven hard. what component do i need to measure across and to what value

thanks

Joe Rasmussen "Trans-Amp" - 40 Watt Transconductance "Current Amplifier"

.
PLEASE BUILD THIS WITH DUE CAUTION!

[Click on it to enlarge]



There are good reasons why there are no "Current Amplifiers" on the market today, with exception of the Nelson Pass F1 and F1J amplifiers. This DIY project is about building a low cost 40 Watt Transconductance Amplifier using National Semiconductor's LM3875T.

WHY BUILD ONE?

Before going ahead: READ THIS BY NELSON PASS: Current Source Amplifiers / Full Range Drivers

Conventional amplifiers are of course "Voltage" types, where the amplifier outputs Voltage similarly to what we see on an oscilloscope with X-Y axis' representing Voltage (vertically) versus Time (laterally). The current is dependant on the load.

With a "Current" type amplifier, this is far less intuitive to understand, but basically it is the opposite, here the voltage is dependent on the load.

It becomes then clear that the Voltage Amplifier needs to have a low output impedance, so that the amplifier can control the Volts without any sagging. Effectively, the Voltage is 'regulated.'

What is not so clear is that a Current Output Amplifier needs to have a VERY HIGH OUTPUT IMPEDANCE!

So a Voltage Amplifier is defined by its Low Impedance.

A Current Amplifier is defined by its High Impedance.

The notion that there is any such thing as "Damping Factor" - with a Current Amplifier - forget it!

Indeed Damping Factor is largely a myth, what really happens, as Richard Small told me way back in 1975 (he is the S in T-S), that any series impedance/resistance with the Voice Coil erodes Qes and if high enough, destroys the speakers Bass Alignment - so that the Electrical Damping Qes within the speaker is non-existent.

If the DCR of the Voice Coil is 6 Ohm and Qes = 0.5, then an additional series of 6 Ohm will double the Qes = 1.0... and so on. Your Bass Alignment no longer works.

SO THIS AMPLIFIER CAN DAMAGE THE WRONG SPEAKERS!

For the technically minded: The Qes and Qms of the driver that determines its part of the bass alignment, these two are in parallel. If the Qes is eroded completely away, then take note of the Qms as the real Q of the alignment. That way we can plot what that particular alignment does in software. Enter T-S Parameters and Box details, but modify Qes to 1000, enter correct Qms value, then it will plot the actual 2Pi response when driven by a current amplifier.

Also, the Crossover (High Pass) to the Tweeter could also damage it in a very short time.

Yes, the use of Current Output Amplifiers are suitable for Full Range Drivers and also speaker systems that are designed to work with current.

Such as the latest Elsinore Mk6 Loudspeaker Project.

Cheers, Joe R.
.

I am returning to the idea of building some high quality solid state power amps, powered by +/-50v or 60v, that have not FETs at the input, or MOSFETs at the output.

For the latter I have my reasons, for the former I couldn't find a dual-FET being sold by Mouser that could be used on an LTP pair, even with a cascode.

Suggestions?

After seeing the reviews of the Douk A5 I am trying to run 1x technics 1210 turntable 2x bose 301 speakers. Having to turn the volume up all the way on the amp to get any decent level of sound out of it and to be honest at the moment I am not impressed. Also the hiss is terrible. I have also hooked it up with some old wharfedale modus cube satellite speakers have the same result. Question is am I asking too much of this little amp or doing something wrong.

I started building AK4493. Single chip, requires XLR+RCA output.
I've heard that MFB filters are good for audio signals. The final schematic will look like this.
Is this wrong?

I offered to look at a Sugden SDT-1SE player for a friend, the problem appearing to be the well known issue of the loading gear on the tray mechanism.



This is a real heavyweight of a player both in terms of build quality and its audiophile heritage. The internal build quality is superb and Sugden gear is mostly hand built (I've actually had the privilege of being shown around the factory many years ago when this player was being replaced by the later CD21).



The DAC is the Philips TA1541 '1 Crown'



The PSU



Inspection showed the gear was well and truly annihilated. More of a surprise was that it was almost glued to the shaft by some mysterious green stuff. I can only think this is some remnant of old grease that has baked and dried solid. ISO wouldn't touch it and in the end it had to be scraped off:



A new gear was fitted and reasonably generous amount of a special plastics/metal compatible grease applied. The replacement was advertised as coming with the belt but the belt that arrives with it is only a fraction the size of the original which fortunately was still soft and supple.





The mech removed from the player:



And then a curiosity......

The tray operated smoothly and quietly but there was a little issue that was quite unexpected... the tray motor over ran for around a second and a quarter on each eject cycle. The loading part was perfect, just the eject with the issue. There is only a single micro switch that operates when the tray is either opened or closed and monitoring this showed it to be working correctly. So this was odd. Slipping the belt off and opening the tray manually by hand saw the motor behave correctly. Weird.

A long story short but I wondered if this could be either some contact bounce (unlikely and it didn't really fit because I would expect the tray to immediately reverse if that was happening). The other dark though was the firmware being programmed to run the motor for a set minimum time and only after that time elapses will the system control accept the electrical input state of the microswitch.

I added a 22 ohm in series with the loading motor. Perfect. Hmmm. How low can we go. Seems like around 5.6 ohms as a lower limit. I fitted a 10 ohm and for good measure added a bi-polar 47uF across the motor. It operates perfectly, the tray is smooth and fast and has plenty of torque. Any slow down in tray speed due to the lower voltage is imperceptible from a user point of view. It will also be much kinder on the gear not to be rammed into the end stop with the motor still powered.

I have asked Sugden if there is a known issue for this......

Hi, could anyone send me the USB firmware of said Denon home theater receivers?

Hi, All

Announce some SMPS+Class D amplifier integrated modules here:

FFA001V3
Output: 2x150W @ 4 / 8ohm
Input: 85--265Vac, constant power SMPS
Size: 90x150mm
Price: $49.9/Unit, w/o shipping (Inc. I/O buffer and mating cables)

FFA001V3-HB
Note: Configured as a high-bass mode. CH1=300W@4OHM and CH2=120W@8OHM, similar to the Pascal U-PRO2
Price: $54.9/Unit, w/o shipping (Inc. I/O buffer and mating cables)

FFA002V2 (1U height)
Output: 2x300W @ 4 / 8ohm
Input: 85--265Vac, constant power SMPS
Size: 95x200mm
Price: $99.9/Unit, w/o shipping (Inc. I/O buffer and mating cables)

FFA003V1
Output: 1x150W @8Ohm / 1x300W @4ohm
Input: 85--265Vac, constant power SMPS, heavy-duty design
Size: 90x245mm
Price: $64.9/Unit (Inc. AL base plate and Volume IO buffer) w/o shipping


PM me if you need more information.
Thanks~

Pics of FFA001V3












Pics of FFA002V2

Pics of FFA003V1



Misc
--- FFA001_V3 spec sheet & Test data;

--- FFA001_V3 & I/O_V1&I/O_V2 dxf file;

--- FFA001_V3 RearPanel_XLR 3D drawings;

--- FFA001_V3 RearPanel_RCA drawing and PDF;

The problem is that the cartridge pulls in but does not pull the tape around the head. There must be a switch or a sensor somewhere that signals that the cartridge is present. Can someone guide me on what to check!
Thanks!
Meelis

Precision matched quad 2SK182ES with the curve data.

They were bought few yeas ago from Tomoaki Watanabe(Japan).

Only shipping to US and Canada, 450USD$ or 640CAD$ Plus Canada Post package with Tracking (Paypal family or firends option).

GTA (50km from Aurora) can be delivered or picked up.

These are very good staff and hope they will end up with a SIT amp lover.

Newbie here, interested in learning more on budget bookshelf DIY designs and kits. I also find 3D printed waveguides and unity horn designs very interesting and would like to learn more 👍

all my old inductors use copper wires with diameters between 0.8 and 1.1mm.
i wanted to get a very long coil and try to make one myself. any advice on diameter?

I am interested in DIY acoustics and vibration management

Hi there. Was looking for information on Daphile OS and found this forum. Thanks for letting me in.

Hello everyone, my name is Robert.

I joined the forum in 2015 because I was looking for a DIY headphone amplifier. With the knowledge from this forum (I am personally very weak in electronics, but I try to read with understanding and I have a small soldering iron and a cheap DMM 😉 ) I made a headphone amplifier The Wire SE-SE. Unfortunately, a few weeks ago the amplifier broke down - after almost 10 years of use. I decided not to repair it but to try something else. Now I bought an unfinished Objective 2 and started my "DIY" journey again. 😉
Greetings from Poland, Robert.

I rescued a pair of B&W DM603S3 Speakers thrown out on the street. I replaced one tweeter and sent a kevlar driver to The Speaker Exchange in Florida to replace it's torn dust cap

This is was first entry into the world of DIY Audio.

I've created an account to discuss the several things I've done with these speakers since. I've used this forum as a reference and figured I should share my findings as well.

Looking forward to productive conversations!

Hello everyone! Im a big music lover and a newbie about audio stuff but im slowly learning!

I am designing studio monitors for an 800 sq. ft room that need wide dispersion and more SPL than I can get from standard hifi drivers within the budget I was given. There will be subs so I don't need the mains to go much below 50 or 60Hz. I will likely be using two Faital Pro NFE400 woofers for 50Hz-300Hz. I plan on using a compression driver and a horn for 1500Hz and up. I need recommendations on a mid-range driver. The system will be all active with a MiniDSP processor and a Buckeye 6 Channel Hypex Ncore amplifier (500 watts for the low woofers and 250 watts each for the mid and high).
These are the three mid-range drivers I'm looking at (mostly because they're round and that will make it easier to get them flush mounted on the baffle since I don't have a CNC machine). They also fit the budget which is around $100 a driver.

Ciare CMR160 6.5" Full-Range Driver 4 Ohm​

LaVoce MAN061.80 6-1/2" Neodymium Midrange Woofer 8 Ohm​

B&C 6PEV13 6-1/2" Midrange Speaker​

I'm leaning towards the B&C driver because of their reputation, but I am unable to find any independent measurements, especially distortion. These speakers will be used to mix on and I am hoping that they can be as transparent as possible after I flatten them out with the active crossover.

Thanks in advance for your thoughts. I would love to hear from anyone who has used these drivers or has another recommendation.

Anyone else use the Dayton Audio SPA300-D 300 Watt Class-D Subwoofer Plate Amplifier?

I am experiencing a 1500hz whine. It occus even without the interconnects, and it does not change in volume when adjusting the volume knob.

Hi!

I`m having a literally burning problem with my NAD Monitor Series 5K player: one of the two transistors controlling focus coil gets very hot - 75-80C with heatsink (!), without heatsink it went as hot as 150C before I turned the player off.

I know there`s a known problem with this player regarding transistors driving focus coil overheating to the point of damaging solder joints, there`s even a service note describing the problem and suggesting replacing said transistors with physically bigger ones for better heat dissipation. I did so when the player started skipping (after ruling out pickup wear or damage) along with replacing bad capacitors (the real cause of skipping). The player works great now, but that one transistor still gets scorching hot and I don`t like that.

My question: is this normal for this player? I Can`t tell without other unit to compare. I got the service manual, run adjustment procedures, all seem to be OK... anyone with NAD 5000 willing to open his/her player and measure (or feel with a fingertip 🙂 - but careful!) the temperature of Q102 and Q103? Or maybe someone already knows what`s going on? Please help!

Thanks in advance!

I've upgraded to one of Ivan's newer transformer pcbs so this is now surplus. It has 1:4 transformers on board, and was originally configured with I/V resistors on the output across the secondaries but on advice from Ivan I moved the I/V resistors on the input side, across the primaries (hence them being soldered under the board), and took the opportunity to upgrade them to vishay foil types.

£95 posted in UK, international postage at cost

What happened to the nice guy from BAA? He used to build one amp per day. Nothing happens anymore. Does somebody know something?


http://buildaudioamps.com/projects-description/

This is a realisation of Papa Nelson F5 by Fab of Fabaudio FSSA class AB amplifier.

I made this amplifier with full carbon resistors. I wanted a high end Lateral mosfet to drive very difficult 4 ohm {2.4ish actual) with my own twist. A more musical yet powerful amplifier. It will be driving nht speakers and kharma GLE. Both very power hungry.

It's powered by Swedish lindersberg transformer. 26vac. Output to a speaker protection. Diy slowstart using h3y omron. 4x10000> Inductor >5x10000uf capacitor. I already tried capacitance multiplier but decided this is a better approach to achieve a more textured rich sound.

I'm using Ecw series. Dual transistor per die. 35vdc ct 400ma and above. Was told by Papa Godzilla that I could get 100w. With about 4 percent class a.. Whatever that means.

I'm progressing very slowly for this one as I want it to look great and sounds great. I had thus pcb for 6 months and slowly collecting parts. Learning while building. So I only post it now as it's near completion. I am not well verse with any electronic's theory. But a buddy of mine who reviewed the circuit said.. This iwill be worth the effort. Do it. Thus a more serious effort.

Fab makes absolutely great build manual. It's very easy to build. And he is also great in supporting this build. I have some difficult to get parts and got help. And also a couple of transistors replacement. Ztx795 is not easy to get here so I replaced with bc639 and bc 640. Eveyrhing is matched as closely as I could. Since I'm a noob doesn't hurt to be more careful.

Hello, does anyone have any experience with a Dayton HTA200? thinking about buying one for a spare room. Wondering if they are worth it or just novelty junk? Thanks!

​

Hi,
a well-known one has bought such an Amp https://de.aliexpress.com/item/1005006773111211.html?gatewayAdapt=glo2deu
The Amp gives hum to the speakers. He measured about 34 dB. He ask me for a look to this amp. I have a little bit more knowledge...little
There was a connection between PE at different places in his amp. One spacer had connection to one heatsink on the boards, used for the drivers, wich is grounded.
Input minus was grounded on both boards and to PE, because PE is connected to the housing. The chinese used the board metal spacers for grounding.
No loopbreaker or resistor in the amp between PE and powerground. Something like a starpoint was made on the power pcb. Powerground and speakers are connected.

I know that the L20.5 has no groundlift resistor. PE ist connected to the housing now, no connection to the powerground anymore, but the amp is still humming.
I remembered i found a schematic in the i-net. I have made a picture from this schematic, hoping it is correct.

My idea is to put a ground lift resistor in at the input, its missing. I have drawn a new plan with my little knowledge. Could you please tell me if i am right with my drawing ?
I want to use a starpoint, make a connection to the signal ground and will use a loopbreaker. I had great sucsess (with help in this forum) using this things in my FH9 Amp to lower the offset. ( i got no hum before).
Picture 3 shows the schematic. I have marked the changes in red i want to make on picture 4.

I have seen that the rca wires are very long, behind the L20.5 board and near to the transformer. I will try to turn the case heatsinks to get a shorter way.

Thanks for helping

Peter

Hello !

Here is my first post about my recent work around speaker building.

This forum has been a great source of learning for this project, I guess it's the right thing to do to show you the actual results !



This project began with the aim of building a speaker system for listening sessions in various locations around my home. The brief was for something that sounded good, big, within a manageable budget and with DSP capabilities to adapt to a wide range of different listening conditions.

So it's a project conceived at the crossroads of Hifi and PA philosophies.

This being my first loudspeaker manufacturing project, I turned to the well-known recipe of a 15’ BR in a large box (135L), with externalised compression and its horn. For obvious design and manufacturing reasons.

The choice of a DSP also led me towards an active crossover. This led me towards multi-amplification.

Here's the list of components:

15‘’ Faital Pro 15PR400
2‘’ Beyma CP750Ti
B&C ME60

Behind the scene:

DBX DriveRack PA2
Crown XLS 2002 (for the tops)
Crown XLS 2502

The project is currently at the end of its first phase, and there's still work to be done. For example, the horn is due to be replaced, along with a potentially better tuning of the port, and a fair amount of cosmetic finishing.

The system is currently located in my living room, which is not particularly practical for listening at correct volumes and which has some modal resonance problems. When the warm weather arrives, I'll do a series of outdoor measurements, which I'll post here if you're interested!

For the moment, and after several weeks of critical listening, I'm happy with the result as a first project, although I'm not reinventing the wheel, this simple system ticks most of the boxes in the desired specifications.

My first criticism would be that the vent perhaps deserves better tuning. Although I've followed the measurements given by WinISD, I feel there's more to be done. Fortunately, I've made sure that the vent can be modified more or less easily.
Although the compression is effective in its frequency ranges and pleasant, I'm missing quite a bit of information beyond 10kHz, or even lower. That's why I'd like to add a remote tweeter, (Fostex T90A, Visaton TL16H etc), with its share of questions, but we'll certainly have the opportunity to discuss them!

There's still some work to be done on the insulation, but after several tests with different materials, 45mm cotton panel glued on the internal sides and lower back panel seems to be giving the best results for the moment.

The ME60 horns were chosen temporarily to start listening, but are due to be replaced. Not having had the opportunity to make comparisons with other horns, my criticism is limited for the moment. I'd love to produce my own horns, and that will probably be the subject of another dedicated post.

Here are few pictures of the fabrication:






Feel free to ask for details about the design, or even the plans! One of the goals of this project is to provide everything needed for anyone who wants to build it themselves and improve upon it!

Hi.

Those are 90% labelled bianchi, some philips are available too.
Do not hesitate to message me if interested.

Prices depend on value and availability, but I will keep them as reasonable as possible.
For instance, 18k 400v caps are 2,5 eur each.

Shipping worldwide from Spain is very reasonable, tracked. I'm shipping to USA, Australia, Japan... all the time, at around 8 eur. Same with Europe.

All typical values available!!
Plenty of 22k, 100k, 10k, 2k2 @ 400v etc