Apologies if this isn't the correct location, but since I'm building an F6..... Someone mentioned using a (from memory) a cl30 thermistor it seemed in place of a soft start to prevent blowing a fuse at power up. Acceptable? Thoughts?

There are three types that I would consider "audio grade" resistors:

1. Mundorf MOX resistor
Mundorf MOX Resistors 10 Watt: Madisound Speaker Components

2. Mundorf M-Resist Resistors 20 Watt
Mundorf M-Resist Resistors 20 Watt: Madisound Speaker Components

3. Mills
Mills 4 Ohm 12W Non-Inductive Resistor

I personally have used Mundorf MOX and Mundorf M-resist. The MOX didn't seem improve the sound but I think the M-resist did smooth out the treble at least that's what my memories told me.

I haven't used Mills so I am not sure how it compares to Mundorf resistor.

By the way, which is the better cap or at least what would be your preference: Mundorf M-Cap Supreme or Jantzen Audio Superior Z Cap? They are about the same price.

Hello
I have a few crossovers and and I meters for testing ESR and many other things. And I have a scope
Here’s my question
How can I use my scope to find the crossovers points of crossover for say a 2 or 3 way, I’d like to find where the woofer, mids and tweeters are crossed over at
I also have a diy electronic crossover. It’s prime build was as a 3 way, the former owner did some tweaking to make it a 2 way
I can’t find any info on it. It was made for
A boom buy and so on. Here’s a few pics of it
Thanks guys for any and all help

Hey folks. I have an M2Tech Palmer power supply that has stopped working! It turns on, but somewhere along its path I guess it's decided not to send power. The battery still works, but it's not doing its job. I guess my question is has anyone else had this problem? And if so, how did you fix it?

If anyone has a schematic.. that would be lovely.

Thank you!

Looking at ALEPH 5, I ran the LTSpice. Initially thought the quiescent current should be around 3A per channel, and total dissipation around 200W per channel. But the sim results show only about half of that, see attached.

Any ideas?

Thanks

FS: Satori WO24P-4, 1 pair - Available

I have WO24P-4 1 pair for sale. Visually and electrically 100% condition. Drivers were just measured, and played for ~20 hours. Not soldered. Drivers were tested in this project:
en-EV :: Pkaudio

Original packing available.

Shipment to the most of EU countries.

Price: 260Euro/1pair + shipping cost.

Hi guys, I'm Brad, first post here, been lurking and learning for a while now.
I wanted to share my build of the Forewatt preamp. This one came from the scrap box, and is my first scratch amp build, tube or otherwise. Prior to this I've just repaired equipment, or followed kits to modify it.
The preamp is built in two chassis, one for the audio circuitry, and the other for the power supply. Here's the preamp.
I did check all the old caps before deciding to use them...

Looking to upgrade the ortofon 2M silver with blue stylus to what? The arm mass is 8g , any recommendations on what to go for, Nag300, orto2m black or other?
Thanks.

I have attached a picture of a device on a small booster amplifier. Does anyone know what it is. It in a SOT-23-5 package. I would like to know the specification of it and if there is a through hole equivalent.

Thanks
Tony

Hello All

I have been repairing Klipsch subwoofer amps for about 15 years as a hobby. I have decided to start blogging my repairs and eventually do videos of each one. This thread is intended to be a blog and a resource for information. I will try to answer repair questions as best I can. Comments and tips are also welcome, If you do not have the experience or the tools, PLEASE do not attempt any of these repairs. You will only end up damaging the board and it will end up costing more for a tech to repair the damage. If you do not have a high quality vacuum desoldering station (Hakko or Weller) and a current limited mains supply, you should not be working on these amps. These subwoofers do not have any user serviceable parts inside. If you open up the sub or attempt any repair you see in this thread, you are doing so at your own risk!!!

Silly me.

Due to poor eyesight and difficult to read IC labels I plugged some OP275 (dual op-amps) into a +/-20V circuit that should have used OP27 (single op-amps).

The OP275s did run a little bit warm but not excessively so.

Have I destroyed them ?

Hello all,

I've got a bit of a head scratcher regarding a dead lm3886. Just wanting to find out what caused it.

Many years ago I built the first version of Russ White's monobloc PCB of Mauro Penasa's My_ref Rev C amp (https://www.diyaudio.com/forums/chip-amps/54571-audiophile-lm3886-approach-38.html#post697610). The amp worked fine, but I had to put it away in storage for a couple of years whilst I was living abroad.

Recovered it recently and plugged it in again. The amp was working fine, but, the light dependant volume control in the amp was having a problem with balance (right channel was louder). As I didn't want to adjust it (annoying little thing to work with), I just removed it and did volume control through a standard 10k log pot. Rewired that, turned on the amp, measured a low DC offset at output (3mv) on the work bench.

Put the amp in the desired place, plugged an input (just an old mp3), and again measured DC offset voltage. 31V. 😕

At this point i suspect the LM3886 failed somehow. But I honestly can't find the reason for this (e.g., don't see any shortings, pcb not touching on chassi, fuses aren't blowing, ...). Now, I would imagine these things don't just fail out of the blue. Or do they? Anyone have any insight into whats going on here?

If ppl want, I can send some pics.

Thanks in advance!

just to recommend a wifi multiroom DIY module for those who love audio DIY stuff.
Up2Stream is a small WiFi multiroom preamp DIY module, it supports
-AirPlay,
-DLNA
-MULTIROOM
-Spotify
-24bit/192kHz
-lossless audio files, like FLAC, APE
...

Up2Stream can be integrated into active speakers or amplifiers to upgrade the old ones to the new wifi enabled. attached two pictures for my active speaker integration work.

for more details you may check
Up2Stream WiFi Audio Receiver Module DLNA AIRPLAY analog output
– arylic

and I also found two youtube video, the guy integrate and DIYed an amplifier with Up2Stream
YouTube

YouTube

Hello all,

Got a AMR DP-777 SE and has issue with Volume control - always at max - changing attenuation does nothing on Analog Preamp in. Sounds distorted at max vol...

I have read that the SE upgrade has issues with Volume Control chip...

Have not yet checked the DAC part...

Anyone work on one of these before? Let meknow.

Be good, and safe out there.

Any of you people that use a diy server for music and movies/ are you using regular hard drives or server hard drives ?
I’m asking this because I have over 50 dell and HP and seagate server hard drives
They use the sata input for data and power
I have ones from 360gb up to 2tb
So my question is this, is there a difference between server and pc hard drives? And if so, what is it ? I will post the model numbers of the drives I have , as I know someone will ask this. Thanks for any and all help

Anybody here good at writing data sheets and documentation of your builds?
I usually end up with some coffee and beer stained hand written notes of some basics, such as low- and high end frequency -3dB points, max signal swing, a few distortion measurements perhaps.
And usually I can't find these notes, at least not the ones I want.

So any one here good at writing datasheets? I am thinking in Excel perhaps, then pasting into Word...? Using the home electronic data machine for something other than armchair designing and youtube...

I guess I can just start doing it, but I imagine having a template to fill out, or some better tips, I might push myself to a more complete set of measurements etc.

Thanks

Hi

Yesterday I fell for an impulse and ordered a pair of the mentioned drivers from hifikit.se.
Specs:

Vas 27L
Fs 30Hz
Qts 0.51
30-20000Hz
89dB/w

Picture:
http://www.hifikit.se/showpic.php?p=prod_bilder/Gamma_BBK200F.jpg

I´m already using the bass (same basic specs but without whizzer cone) version of this driver in my closed "subs" and they sound pretty good so I´m very curious about the fullrange version.
The funny thing is that I can´t find any info about them online,
the bass version seem to have been used in a few swedish speaker kits 30 years ago but there´s absolutely nothing mentioned about the fullrange version.

My idea is to use one BBK200 and one BBK200F per channel in a 1.5 way OB setup.
If anyone has any experience of these drivers (both LF and FR versions) please share!

How do you calculate current rating for a power transformer for a tube amp power supply?

Say I have std. 2-pin crystal can. (Mine is 11.289 Mhz)
I want to make the simplest osc/clock possible ... hence, fewest parts-count I assume. The performance should be acceptible, but does not have to be audiophile-grade.
Please suggest a circuit.
Thanks!

Ok, my last thread was closed, due to my asking for help to do something extremely dangerous or illegal (converting an old intercom to a guitar amplifier). I 100% want to make sure I don’t harm myself or anyone else, so is there any value or danger in disassembling the old unit, salvaging some of the components and building a simple amp using that chassis? It already has tube sockets...

Obviously I would need to acquire the proper transformers and other parts.

Today I heard from a reliable source that Jelco is closing due to difficulties related to Covid-19, aging management, staff and equipment as well as poor profitability.


Late last year I purchased a Jelco TK-850L as a desperate last bid to have something reliable, unfussy and decent sounding for general use when I wasn't feeling tweaky. What I ended up was the best sounding and least fussy 12" arm I have encountered to date.


What a shame.


Jelco was OEM for Ortofon arms, as well as a number of others, and I suspect Jelco sourced components found their way into a lot of other people's arms.

Looking for upgrade my car audio system. One of my friend recommends me to get an Subwoofer first and then replace the head unit with an XTRONS DSP head unit. Does it matter to use DSP?

Hello everyone,

I finshed a DIY AMP and came across an interesting frequency response. My AMP should have an 6dB output but when I went to make the test it started increasing at around 2kHz and hit 8dB at 8kHz.
Can someone explain what the problem could be and what the side effects will be if I keep on using it. I've tested it and it sound good till now.

Thank you for helping me

The graph was made in excel, very amateur but I hope it helps

Hi Folks - Wanted this community to be among the first to hear about our new business launch. Excited to hear what you think.

Ostinato Speakers Launches

30 April 2020, Denver, CO

Today, Ostinato Speakers announces its launch of business operations. With a direct to customer model, Ostinato Speakers offers hand built, semi-custom, high end audio speakers at very competitive pricing.

We are pleased to go live with three high-end speaker models: The beautiful two-way Desktop, an innovative three-way monitor, and a no compromise Center Channel. In addition we also supply made to order, hand built audio cables.

Ostinato Speakers are hand built in the USA from quality materials. Featuring: Beautiful cabinets finished in real wood; Ribbon tweeters; Innovations such as user switchable cross-over and open back mid-range tunnel (Monitor).

As exclusive partner with Curt Campbell, we are proud to be bringing his highly regarded designs to market at prices more approachable than the traditional audiophile market offers.

About Ostinato Speakers
Founded in 2019 by a refugee from the corporate world, Ostinato Speakers is dedicated to building high-end audio Speakers at more affordable prices.

Contact:
Ostinato Speakers
info@ostinatogroup.com

Are there any small class D amps to run 2 6" speakers (60 watt rating)
+ a 12" pioneer subwoofer (rms around 400watts)

I've seen some that people use small class d amps at home. Size of 2 cellphones.

Are there any options like this for car stereo. Ideally I want one amplifier to run 2 speakers and a sub. But could buy a separate subwoofer amp

Space is an issue.

This past weekend I spoke with a well regarded turntable manufacturer and he got on the subject of NTC thermistors. He came right out and said it, 'Thermistors are terrible for audio.'. He suggested using a DPDT On-On switch to 'by-pass the thermistor once the power supply transient subsides'. Not his exact words. I'm paraphrasing.

So...I believe that power supplies are important to audio circuits. Considering people spend $40 on hi-end fuses and hundreds and even thousands of dollars on power cords, maybe there is something to this?
Can this one component in the power supply effect the quality of the overall sound on the F5?

I have 5 CL-60s in my dual-mono F5. They were also incorporated in the second F5 that I built. One option is to remove them. Not a good idea, I think. Another is to use a relay circuit. Probably has it's own issues.
Is the suggested DPDT by-pass a good option? Sounded simple enough when mentioned, but are there any pitfalls?

Like to hear your thoughts on this.

For what it's worth, I think thermistors are a simple, inexpensive solution to a big problem. They save us big time.

Thanks,

Vince

I searched on Digikey, Farnell, Mouser and others for these Rectifiers. Couldn`t find them.
Does anybody know where to get them or something equivalent?

Thank you for your help.

Hi,
Here in forum there is nice thread about music spectrum of various genres of music.
Link : Spectrum of Musical Genres
I know cannon shots in 1812 Overture are loud. So it got me curious is there any info on internet/links where Transients/peaks are calculated across various genres of music and mean results are given ?
Thanks and Regards.

What's up guys, just been on a job today and I've been emptying out some old storage sheds. I came across a bag full of tubes and was wondering if there is any way of testing them without having to spend loads on a testing kit?
The valves are mostly mullards, an ecc32, ecc31, em84 etc. There's quite a few and it would be a shame to just throw them. Any help would be great.

Thanks
Adam

Hi guys,
New guy here.
I recently purchased a used Yamaha RX-797 Receiver.

However it will only produce sound if the "pure direct" button is enabled.
Therefore i have no tonal control, balance control, etc.
With the "pure direct" enabled it sounds great but i want the option of it working without using pure direct.

Has anyone got any solution? I note that in 2009 bmwscoot had the same problem and while suggestions were made there's no mention of a resolution

many thanks in advance

neil

im working on a qsc mx1500, repaired some issues the amp was having.
just noticed the channel 2 run hots. At idle with no signal going into it the channel get hot.
probably 40-50 degrees, while the other channel is stone cold,
ive ran it amp sound fine, ran it over an hour, did not have any audible issue.
gotta put the scope on the channel see if i can see anything, i check the speaker terminals for dc voltage, both channels test the same.
does it sound like a bias issue? or what else could cause this?

thanks in advanced

I have another one I need help with, I think these are class AB and I've never worked on anything but class D before.

I received this amp with a blown power supply and a shorted output. Thus far I have replaced the PS FETs, gate resistors (originals were in tolerance but scorched) and all 4 outputs. All with original parts.

The amp currently works BUT:
At idle, one bank of outputs gets hot while the other stays cold and part of the driver card gets hot (pictured below.) The passive components between the driver card and outputs seem to be ok.

I have not yet touched the bias pot. Since it's only one bank of outputs getting hot I assumed there's more work to do. I could be completely though, I don't know what normal behavior for these amplifiers is.

Any advice on how to proceed is greatly appreciated.

Pizzicato, a 250W low distortion CFA amplifier

It is a CFA power amp Diamond input with gain, Cascode input & VAS, driver, Power Laterals MOSFETS.
250W under 8 Ohms, 500W under 4 Ohms.
Very low simulated Distortion (Cordel models) : 0.000020% @ 1KHz, 0.000508% @ 10K. (Simulated @250W)
It was published here to be a collaborative project.
The attachments in this post is the raw project, a development start, just to propose a frame: You will see the changes and improvements in the definitive version.

[edit] The definitive version is in post #428
Pizzicato #428


250W under 8 Ohms, 500W under 4 Ohms.

Bandwidth, without low pass input filter: 10MHz (-3dB)*
Phase margin: 60°, gain margin: 13dB.*
Slew-rate*: 240V/µs (*to be adjusted on the bench)
Loop Gain >100dB up to >1KHz.
0.000002% à 1W 8Ohms 1000Hz
0.000010% @100W
0.000020% à250W


DC coupled with optional added error correction, original Servo, very fast protection(25µs) against DC, internal failure, clipping, oscillation etc that will protect both amp and speakers.
The protection is in Post 378.
Pizzicato, #378

This version (V) is treated like a VFA, but keep the "expansive" behavior of a CFA and high slew rate. May-be a more traditional CFA version (C), with a flat loop up to 10KHZ will come to can figure out if any listening difference. And get an idea of the thresholds of audibility of distortion, if loop gains makes a difference on the amp's character and listening experience etc.

A pair of almost new tweeters Hiquphon OW1

Asking 250€ plus shipping.

Shipping worldwide

Hello,

I am about to order some of the legendary JT-123-FLPCH audio transformers for my F6 amp build, directly from Jensen. They agreed to sell me directly because there is no distributor here in the Netherlands (or anywhere in Europe that sells these).

I only need a pair ($34.35 USD each if we buy 4+), but we can order up to 8 for the same shipping costs ($38.60 USD), all the way to Amsterdam.

If anybody in the Netherlands or EU is interested, let me know and we can split the shipping costs (and potential import taxes into Europe).

Regards and stay safe,
Iván

Hello folks,

I need to make a couple of simple repairs to my Almarro A318B SET integrated valve amp ([FONT=Courier New,Courier,Monaco]2x6C33C, 1x6SL7, 1x6SN7)[/FONT]. Namely changing the selector switch which is intermittently causing issues plus the IEC socket which has a crack in the plastic casing.

While I am in there I wondered about the potential for any simple upgrades by swapping like for like components. A few years ago I swapped the coupling caps and this was a huge step up in performance.

I have already changed the input valves after tube rolling with a small selection of valves.

Is there anything else that could be achieved with a simple swapping of components for better quality ones. The power supply caps perhaps? Could these be uprated by 10% or am I risking damage here and playing with fire? Would swapping for better quality caps at the same rating be worthwhile?

I have attached two images of the amp plus the specs and the schematic which is included in the manual (input and output). Unfortunately I cannot find a schematic for the PSU.

Many thanks in advance.

I noticed that boomboxes and stereos from the 80's or 90's use a lot less amplification than modern sound systems. Not having grown up during that time, I haven't had much of an opportunity to mess around with older equipment. From what I've heard though, they didn't sound terrible or sound underpowered. My grandfather who worked with speakers in the 70's and 80's came to visit a while back and listened to a couple of the systems I had built. He was shocked and almost refused to believe it when I told him one of the systems was pushing 350 watts rms in total, which is not even that high for a modern system. He asked me if I was sure it wasn't more like 30 watts, which would be pretty underpowered for a 2.1 system today. So why did it work back then? Why do modern systems need so much power? Were the drivers just built for higher sensitivity back then?

Hello forum.
First time poster here. I am embarrassed to say I am very limited when it comes to electronics. I can thoroughly install a decent system, I can identify the difference between a mosfet and capacitor inside an amplifier, but that is about it.

About a year ago the magic smoke genie came out of my T3001. I had to have it repaired twice by a recommended shop. The second time, he updated the amp with some sort of additional protection circuitry that it did not have before. Ever since, the amp will make very limited power before activating this new feature and click the speaker output in and out (with the corresponding indicator light). My best guess is it is limited to about 500 watts. It had never done this before the modification. The technician has bench tested the amp and claims it is working fine.

The amp only sees a 2 ohm load (a pair of 4ohm 18's) that seem to perform well. I have tried 2 different smaller amps and they perform flawlessly with the existing wiring and configuration. I have a run of 0 gauge from the battery and a shorter 0 gauge well cleaned ground. A 250 amp alt with a custom smaller pulley. I am confident in my install. As written before, the amp performed well for about a year before the failure. I was told the original failure was the chassis made contact with the circuit board. The voltage never goes below 12v during this issue while the sound tries to cycle on and off. The power indicator is unaffected.

My question is there an easy way to remove or adjust this now overly sensitive protection feature?

So I built an enclosure for a ported enclosure for an 8 inch woofer and I tuned it for just below 40 hertz. Thing is, I don't think I did it right because the bass response is weak without any eq and the graph shows the response I get. The box is something like 1.2 cu ft, so I think a little under 40 hertz is reasonable for an 8 inch woofer. Is there any way to confirm that I tuned it to the right frequency? I do see a bump at 35 hertz but there's also a bump around 75 hertz and the response falls off very quickly after 60 hertz. Is there a way to know for sure I tuned this right?

Hi,
I have been planning on putting together a 3255 amp in an enclosure. I will use the 3e board, LRS-350-48. I would like to also have on-off and volume.

This is where it seems to get a bit complicated. There seems to be mixed opinions of the impact a Pot has on sound quality and avoiding the on-off pop seems also problematic. My immediate thought is to avoid this and use a pre-amp. Then we are talking another piece of equipment and potentially unnecessary attenuation beyond 2VRMS.

I would like to keep it versatile so I can have input from CD player or laptop/phone. My older laptop does have straight digital out but I am not planning on a separate DAC or media player at this point - maybe down the track if the quality of my other gear justifies it. It all starts to become a bit beyond my understanding of audio electronics.

Basically, I am wondering if there is something ready made from china that has some of these features and is big enough that I could substitute the 3255 board and PSU? The fact that I have not come across anyone suggesting this make me think no, but doesn't hurt to ask.... Good enclosures along run at about $80AUD and some of the ready made amps coming out of china look quite nice and are not much more that.

Hi,

I'm about to start my first amp builds (Neurochrome and Purifi based ones) and I've been researching a lot about crimping. Here is what I come up with:

1. For 4.8 mm / 6.3 mm quick disconnects / faston connectors, I'm looking to buy a reliable but affordable crimp tool. I'd crimp these non-insulated and cover them in head-shrink afterwards.
2. For everything else (JST, Molex, etc.) I'll buy pre-crimped wires, as it wouldn't make sense for me to buy the expensive tools needed to crimp these.

What crimp tool should I buy? A cheap, noname Aliexpress / Banggood kind of racheting tool or a simple but high quality non-racheting one?

I know many people buy professional tools here, but I'm only planning to use this for 10, maybe 20 times in total. I'm happy to invest $20-30 in a tool, but not $200+.

For example this is what looks really nice to me, about 20 EUR in Europe.
Knipex 97 21 215 B Crimping Plier




The alternative would be some cheap racheting one like this:
4 in 1 ratchet crimper cable wire crimping plier electrical terminals plier tool kit Sale - Banggood.com



or this:
Paron(R) jx-d5 multifunctional ratchet crimping tool wire strippers terminals pliers kit Sale - Banggood.com


Then for the connectors, what should I look for? What brand, what material, locking mechanism, etc.? Is TE considered the best one?

Here is a filtered search I made at TME.eu about the ones I believe are fitting for me.

About the insulation, I'm thinking about using heat-shrink after crimping as I can make a more precise crimping this way.

What do you recommend?

"The Wiener" TPA3118 amplifier, group buy #3 + "Wiener Pro" prototypes.

People keep asking me for these cards, so it's time for group buy #3!

UPDATE: MAY 24/2016

Group buy is now closed! I'm taking no further orders.

I am building a number of extra cards, just in case some cards that I build don't work. Once all orders have been built and shipped, if any of these cards remain, I'll have them available for sale.

Thanks everyone!

UPDATE: MAY 3/2016

Now taking payments! My PayPal address is:

REMOVED - GROUP BUY CLOSED

Be sure to pay in $CAD, not $USD. Make sure your PayPal mailing address is correct, and you specify what you're ordering (including load impedance) when you make your order.

Here's the game plan:

- I'm going to take payments for the next two or so weeks. I have a bunch of things to build and get ready (programming jig for the Wiener Pro microcontroller, software to run on said microcontroller, Mouser BOM's, etc) in the meantime.
- Monday May 23, the group buy is closed and I'm ordering the PCBs/parts/tools/solder paste/whatever. PCBs are coming from Elecrow and will be shipped via DHL, and should take 1-2 weeks to arrive, arriving in early June.
- I'll bang out and test a Pro card immediately, to ensure everything's OK with the design and get the microcontroller software finalized.
- Assuming all is good with that, I'll start building orders. Orders will be shipped out in order of payment received.

Thanks!

...original post below...

The Wiener:

AudioLapDance put out a request for a highly configurable TPA3116 card in this thread:

http://www.diyaudio.com/forums/class-d/267039-proper-tda3116-pcb.html

One day I was stuck home in a snowstorm, and decided to bang out a card design that met his requirements. Soon several other people started throwing in suggestions and requests, and the design evolved into a very high end design that we all felt pretty good about. AudioLapDance himself proclamed "we have a wiener!", and the name stuck.

Since then, two group buys of the card have happened and a PBTL version of the card was created. People seem to like the card, so I guess I did something right 🙂


Stereo Wiener features:



- New for version 2.0: There's now ground terminals on the input terminal block, to make grounding the amp and source together more convenient.
- Small size: 5x10cm.
- TPA3118 amplifier IC (same silicon IC as the TPA3116, but heatsinked to the PCB)
- Differential inputs, allowing connections from both single ended and balanced audio sources.
- Everything is easily/quickly configurable with DIP switches and trimmer pots. Switching frequency, BD/1SPW mode, gain, master/slave mode, PLIMIT threshold and startup/unmute delay.
- "Wideband" PVCC decoupling; multiple layers of decoupling capacitors and a tight PCB layout provide a very low PVCC impedance, from low frequencies well up into the tens of MHz.
- Extra RC filtering added on the TPA3118's AVCC supply pin.
- Snubbers before and after the output filter.
- Good quality output filter: ICE Components 1D14A, which has a flat current/inductance curve over its operating range, and Epcos B32529 film capacitors. Sagami 7G14A inductors can also be used.
- Multiple output filter options available depending on load impedance - 4 ohm (10uH/1.5uF), 6 ohm (10uH/0.68uF) and 8 ohm (15uH/0.47uF).
- Good quality input film capacitors (2.2uF KEMET film)
- Microprocessor controlled power-up/power-down sequencing with an adjustable unmuting delay. No turn-on/turn-off pops!
- Connections provided for a standby switch and a power/status LED.
- Thermal pad available, allowing card to be heatsinked to chassis if desired.


PBTL Wiener features:



- All of the above features of the stereo Wiener card (It's largely the same design/layout)
- "complete overkill" output filter - Coilcraft VER2923 output inductors and paralleled Epcos film capacitors.
- Configurable for 2 ohm, 4 ohm, 6 ohm and 8 ohm operation.


Costs:

Stereo and PBTL cards are available as a bare or partially assembled PCB, or as a fully assembled card.

Bare PCB and preprogrammed microcontroller: $12 CAD
Add a soldered on, bed-of-nails-tested TPA3118 chip: $15 CAD

Fully assembled and tested cards: $100 CAD for a stereo card, $105 CAD for a PBTL card.
"Filter kit": add $18 CAD for stereo cards, $25 for PBTL cards. This is a bag of extra output inductors and capacitors, allowing a card to be reconfigured for 4/6/8 ohm operation.
"Thermal kit" for Stereo and PBTL cards: add $12. Includes a H48G series thermal pad, standoffs/spacers, and #4 hardware for chassis mounting.

Shipping costs: For bare PCBs, $10 CAD. For up to three fully assembled amplifiers, $15 to the USA and $20 international.


The Wiener Pro:





The Wiener Pro is a TPA3250D2 based amplifier I've designed. The TPA3250D2 is a higher end, higher power successor to the TPA3118 chip, with a number of improvements and new features.

I will make some of these cards available to offset the cost of prototyping. I must warn however: this is a more complex design than the standard Wiener card, and there is a possibility of design mistakes being made. So cards I mail out may have wire bodges/trace cuts or worse, or may be delayed because I've had to order another set of PCBs. This shouldn't happen, but it could 🙂

Features include:

- Small-ish size (75x125mm)
- The same "optimized" design philosophy as the stereo and PBTL Wiener cards. "Broadband low impedance" decoupling on the TPA chip and everything else that needs it, and a good selection of components. Audio performance should be limited only by the TPA chip itself, not by anything around it.
- "Proper" balanced audio inputs, using a LM4562/LME49724 based, fully differential instrumentation amp to receive audio and convert it to a balanced/symmetric signal for the TPA3250D2. The circuit is able to handle several volts of common mode voltage, and has great CMRR even with unbalanced source impedances.
- Fixed 20dB gain, gain can be increased further by plugging through-hole resistors into provided sockets. Resistors provided for 23, 26, 29, 32 and 36dB gain.
- "Deliciously overkill" output filter using Coilcraft VER2923 inductors and Epcos B32529J capacitors.
- Onboard microcontroller which provides turn-on/turn-off muting, fault handling and low voltage protection. Outputs provided to drive a bicolor red/green LED, providing status and clipping indications.
- 2 position DIP switch to select the TPA3250D2's switching frequency.
- Onboard switching regulator which generates +-12V for the audio front end parts, enabling a single 18-36V power supply to be used to power the card.
- Board is configurable (with some straightforward soldering work) to operate in PBTL mode.

Costs:

Bare PCB and programmed microcontroller: $20 CAD.
Fully assembled/tested board: $185 CAD.
Filter kit (additional output filter inductors/capacitors, enabling board to be reconfigured for 4/6/8 ohms): $45 CAD
Thermal kit (same kit as the standard Wiener thermal kit): $12 CAD.

Shipping: For bare PCBs, $10 CAD. For fully assembled PCBs, $18 CAD for up to two boards to US addresses, and $25 to international addresses. PM for a quote on larger shipments.

Have Martin Logan dynamo 10" sub. Looks like it's a bash amp used on many other subwoofers.

I don't see anything blown except dsp 104 thermistor. With amp off the sub I put a new fuse and saw sparks coming from green dsp 104 thermistor

Fuse blows instantly

Thermistor reading off the amp is 17ohm.

This part is supposed to be 10ohm and 4A.

Could just a thermistor cause the amp to blow fuses or it's something else that caused this amp to blow?

Output transistors measured consistently around 1040ohm on outer terminals. Using diode test

Here is a thread of another gentleman with same amp on klipsh subwoofer

https://www.diyaudio.com/forums/power-supplies/192365-bash-amp-power-supply-repair-3.html

And pics of mine. I think it's power supply issue. Just curious if just s thermistor failure could be the culprit.

Hi guys anyone on here give me some advice on these rare beast?

McIntosh MC4000M | eBay

Thanks

Vinyl enthusiasts, keep in mind that the several forms of distortion are NOT in the groove - they are generated upon playback. Mastered on a linear-tracking lathe and cut with a chisel shape that is flat across the groove, tracking and tracing distortions are nil. However especially if your pickup stylus is spherical (aka "conical") or even a fat elliptical, tracing distortions (pinch, "poid-like," wall contact due to too light pressure and skating) can add 10% or more distortion and analog clipping (aka "sibilance"). Known from the LP's introduction in 1948, inner groove mistracing limits maximum level undistorted sounds to less than 2kHz (10kHz with a line contact). From the 1970s mastering engineers used line contact styli to monitor potential trouble spots, restarting a new lacquer if playing with the best stylus had distortion. I "wrote the book" on the Phonograph - containing the science, HF & wear charts, free tools for alignment and resonance optimization, and high-performing DIY projects.

This morning I received two KEF C30 speakers for free. I transported them home on the back of my bike, individually covered in a blanket and then tied together. When I got home one of the two speakers produced beautiful sound, the other only produced almost inaubibly soft high sound. I changed the cables and that proved the problem to be in the speaker.

Specs of the Kef C30 speaker:
KEF C30 - Manual - Two Way Stand Mounting Loudspeaker System - HiFi Engine

I decided to open the faulty speaker to see if I could find any damage of the transport by bike and I took some resistance measurements of different parts of the electronics.
However my knowledge of electronics is limited to what I learned in secondary school physics and how a cross-over exactly works is a complete mystery to me. So I need some help with investigating what the defect in this speaker is.

Description of situation when I opened the speaker:


Woofer (see info in attached pictures) was attached with a red and a purple cable. Red cable was attached to the connector on the driver marked with red dot.








Tweeter was attached with purple and blue cable. Blue cable was attached to tweeter-connector with red dot.






I disconnected the woofer and the tweeter to do the measurements. I did not remove the cross-over from the back of the speakerbox. As far as I can see without removing the cross-over I do not see any sign of over-heating damage or any broken solder or loose cables.




Resistance measurements:
Red binding post on outside red to red woofer cable: 1,0 ohm
Red binding post on outside red to purple woofer cable: infinite
Black binding post on outside red to red woofer cable: infinite
Black binding post on outside red to purple woofer cable: 0.6 ohm

Red binding post on outside red to blue tweeter cable: infinite
Red binding post on outside red to brown tweeter cable: infinite
Black binding post on outside red to blue tweeter cable: 0.6 ohm
Black binding post on outside red to brown tweeter cable: infinite

Between both connectors on woofer: infinite
Between both connectors on tweeter: 6,7 ohm

The conclusion I draw from these observations is that the woofer is probably broken (because of it's infinite resistance).

Can any of you shine any more light on my findings? Or maybe you have instructions for what more I should measure/investigate.
I did not dare to test the woofer or the tweeter in the other, still working, speaker, because I'm afraid that I could damage the undamaged electronics of the working speaker by introducing a faulty woofer/tweeter to it. Is this a true risk?


I'm looking in to this because I love to learn new things and also I hope to be able to repair/replace the broken part even if it costs some time/money.



Thanks in advance.

I’m putting together my first rack and so far have:
zenith CD 8000 (will be EV TGX7)
Zenith CD 5000 (will be EV TGX5)
Electrovoice 1212
Behringer Ultradrive Pro DCX2496. (Will be DC ONE)

I have a Penn Elcom PDU16-UN Power Conditioner. 8 x Universal (UK/Schuko) Outputs will this suffice or will I need to use separate 10A conditioners

New to this site! I want to consider building a portable PA system powered subwoofer. Will primarily be used for outdoor events. Somewhere in the 1200w continuous range, 136db spl@1m range. I think it could be fun and possibly cost efficient to a $1500 sub. Can you point me in the right direction? Maybe even an old thread on this. Thanks!

Hi There, all well?

I have a question, I do want to make a shifted triangles with some digital components, however, I am not that educated with digital stuff but I think here will be guys who are.

It is about this part of a tut for class d. What do she mean and how this will be done, I do now about some things afcourse, like ripple counter, dflops.

The paper was not complete with drawns so I can not see how she did this, but it is interesting.

To ameliorate this issue, a four-phase triangular wave generator is used. This circuit includes a master integrator, a ripple counter, an encoder, and a 4-bit integrator. The master integrator is implemented to serve as an oscillator which generates a pulse signal, Q1. Since the master integrator circuit has identical behavior with the 4-bit integrators, the pulse signal Q1 can adapt to the characteristics of the 4-bit integrators. The operation of this master integrator can be described as follows: Assume the integrator is initially charging and its voltage begins to build up at its output. When 4V is
reached, the Q2 of the SR2 latch is triggered to logic high, MI1 is switched off, and the voltage of the integrator will remain still. When the external CLK
signal set SR1 to logic high, MI3 is switched on and the voltage of the integrator begins to decrease. When 1V is reached, the Q of both SR latches
becomes logic low, MI1 and MI2 begin to conduct and the voltage of the integrator begins to increase. These operations repeat indefinitely. Since the capacitor of the master integrator is only half the capacitance compared to the capacitors of the 4-bit integrator, the oscillation frequency of Q1 is doubled in comparison with the output of the 4-bit integrator, VC'. An encoder is used to generate the 4-bit phase control signal The CMFB circuits of the fully differential OP-AMPs will also help to stabilize the DC level of the output triangular waveforms.


The system is multilevel class d, two sets of triangles 180 degree out of fase, with offset above and below zero, this digital one does prevent overlap.

Maybe discussion is interesting about clocked class d designs.

thanks and stay save.

about 1.65 cubic foot bulk - built by Weltersys's Dad circa 1960-63.

tuned probably in the upper 90's. Larger than Karlson's K8. Beta8CX, B52/Celestion compression driver - 1.2mH/10uF lowpass - 4uF/0.35mH/12uF highpass with L-pad

would be good in a sub system - very nice on piano and percussion without any back or front chamber damping.

I'll have to open it up and get a look at the slot vents' dms

It ran well with a Visaton BG20 but I need that multiway treble power for percussion to sound "real".

When a couple of slots are blocked, it sounds very much overdamped.

The lowpass gap area = Sd for the average 8 inch speaker.

Its almost large enough for a 10 so a 1.09X version might be fun.


Rough Drawing

I am one lucky son of a gun. I have a friend who recently lent me a Vanderveen Ultra Lineair 40-S amplifier which was hand-built and gifted to him by Menno Vanderveen himself.

The line voltage in my listening room is always high - from 125V to as much as 130V. I thought it best to reach out to Menno and confirm my doubts about running this lovely old tube amp on such high voltages. He replied and let me know that 115V 60Hz would be the optimal supply for the amp.

I have read some things about bucking transformers in the past and I did a lot more reading to gain a good understanding. As is often the case, Rod Elliott's website was especially informative. His article on bucking transformers and some threads here and on vintage radio and guitar amp sites led me to come up with the attached design.

The DPDT switches and the Hammond 185D20 transformer are on order and I will report the results when I have them. I'm thinking that using a transformer with 2 x 120V primaries and 2 x 10V secondaries should give me the ability to reduce the line voltage by roughly 4.2%, 8.3% or 16.7% depending on how each switch is set.

The 10V output voltage rating for the secondary windings is at full load so I expect the voltage will be greater when the current flowing through the windings is lower than the 2.2A rating. On the other hand, Rod Elliott's article says that wiring the bucking transformer autotransformer-style reduces the theoretical voltage drop from 10V to 9.25V. We will see the end results when the project is completed and connected.

Diagrams and some calculations are attached and special thanks to Rod Elliott for sharing his wisdom so generously.

Hey diyA - I posted my completed 45 parafeed amplifier recently, this was the one that came before it, my first design-to-build amplifier. Again, nothing innovative, but I am proud 🙂 I spent 2-3 months planning and learning about tube design, then built it (except for chassis, which was made by Landfall Systems). I am still relatively new to the forum, so not sure if many share their completed work, but what the heck.



It is a two-stage SET, MH4 / REN904 (and equivalents) input with cascode MOSFET CCS load. Output tube is the indirectly heated version of the 6B4G, the 6A5G with cathode bias. Output transformers are Lundahl LL1620 60mA.

Here is the amplifier schematic.



And power supply.



Since this was my first design, there are some aspects of the power supply that are a bit...unconventional. Rectifier is a hybrid diode-tube full-wave bridge using the U18/20 4V rectifier. There is also a combo rectifier socket - it can use 5Z3 as well. It is a CLCLC supply using 27H of Lundahl chokes per channel. The unconventional aspect is the driver stage is the first tap in the supply given the higher B+ requirement of the CCS load. A somewhat significant amount of internal restisance was added (1.6K per channel) to drop the voltage for the 6A5G B+, which has been split into two separate rails. The sound is very good, so the added resistance doesn't seem to have had a deleterious effect.

Bias points.

MH4 cathode: 2.44V
MH4 plate to cathode: 184.4V
6A5G cathode: 45.5V
6A5G plate to cathode: 251.5V

Here is the interior. May be going back in to better optimize some wiring.



Rear I/O with Goldpoint switch for the headphone output.



Here is the frequency response, down about 1.7dB at 20kHz, which might be investigated.



Some photos with my headphones, before the amp was placed in my stereo.





It will be driving a pair of 98dB/W stand-mount Omega speakers and a pair of 92dB/W Snell J/II speakers in my smallish room.

Thanks for looking!

Hello

I looking for a full schematic to Threshold fel ten/HL Not ten He!

Hope anyone can help.🙂

I've been working on an ambisonic microphone with four cardioid electret condenser capsules that are all very closely arranged together. The problem is that the mic connector wires are super close together and I worry they may short if the mic is bumped in the wrong way. What I want to do Is fill the cavity between the capsules with epoxy so that the whole thing is more rigid and safe. My question is: would filling the spaces behind the mics mess with the polar pattern of the mic? My understanding is that the mics have holes drilled into the backs of them to help determine their polar pattern and I need them to remain cardioid. Picture here of the project.

Does anyone know if any of these amps are still available anywhere for the NHT VT3 speakers?

There is a Wiki here which contains all the project information, documentation and details for all "The Wire" projects:

http://www.diyaudio.com/forums/showwiki.php?title=The_Wire_-_All_Boards_and_Kits_Explained_Here

Hi Guys,

It has been a while since I’ve posted a completely new project, but I have been working away on a variety of fun things in the background. This one, in particular, I felt was worth sharing as I’ve been enjoying it immensely and I think others will too!

What I’ve gone for is a clean and simple 3-stage fully balanced phono preamp with passive RIAA nested between the first and second, and second and third stages. Here are my design criteria:

1. Above all, it must be a low noise design even with high gain (60dB @1kHz) for LOMC cartridges.
2. The RIAA curve must be very accurate.
3. Must have low distortion.
4. Needs plenty of overhead for wide dynamic range.
5. Needs to easily accommodate MC or MM parts and provide proper loading.

To accomplish requirement number one, my reference design uses on of my favorite op-amps, the LME49990, but you could build this with pretty much any single op-amp your heart desires. The LME49990 has an extremely low input noise density of 0.9nV along with unrivalled distortion performance and very high PSRR. I also opted for a three stage design which allows each individual stage to have lower gain than a single-stage or two-stage topology. Finally, it’s impossible to achieve low noise without a very good supply, so I turned to a pair of LT3042 regulators to provide an extremely quiet +/-16V supply to the op-amps. This has all been layed-out on a very clean 4-layer PCB with full ground planes and ideal shielding of all critical signals. Finally, there’s the differential topology itself which I will discuss a little later.

For my second requirement, the passive RIAA stages are designed specifically to be extremely accurate, while using simple off-the shelf parts from Mouser or Digikey that don’t cost a fortune. The accuracy comes from selecting the values to accommodate available 1% film capacitors, and using multiple parallel caps to reduce tolerance and simplify matching if desired. This is done in conjunction with 0.05% thin film resistors, and the resulting RIAA curve is an incredible +/-0.05dB from 20Hz to 20kHz without any matching of components whatsoever.

Requirement number three is met thanks to the very low distortion op-amps, and the RIAA loads designed specifically to keep the op-amps under ideal operating conditions. The op-amps also fulfill requirement number 4 by being able to run at +/-18V if desired, and having a fully differential design means they can swing over 22VRMS at the output without clipping!
Finally, I have left some open component slots for easy loading of either MM or MC cartridges to fulfill requirement number five. The user can add whatever resistive or capacitive load they might need.

The last aspect of this design I would like to talk about is probably one of the least conventional, and it’s one that should appeal to DIY vinyl lovers. The differential topology can accommodate the standard RCA cables you usually find on the back of turntables, but in addition to this, it allows a user to run a fully shielded twisted pair all the way from the cartridge terminals to the input of this preamp. This might not seem like a big deal, but of all the sensitive areas in the playback chain, this is by far the most susceptible to picking up noise. Putting in the effort to wire this part properly pays dividends in reducing the overall system noise and improving dynamic range.
For now, let’s discuss the performance of this preamp, and in later posts I will address the best possible way to wire up the cartridge for optimal noise performance.

Let’s start with a few pictures of the completed PCB, and I’ll follow up with some measurements of the finished board in the next post!
I have compiled all the details and links to schematics / BOMs on the Wiki page here under section 3.4:

The Wire - All Boards and Kits Explained Here! - diyAudio

The link to purchase boards is at the bottom of the phono section on the Wiki if anyone happens to be interested

Regards,
Owen

Besides the usual live versus Memorex stuff...

20 years ago I was in on a business trip in Asia, and the telephone system (Japan?) had a background residual noise which sounded like many time multiplexed voices. It had a discernible human-voice quality. How?

At a radio-telescope, they setup two large (10'?) dishes at maybe 100 yards distance, aimed at each other as a science demo for kids. I setup a portable radio having some bass output at the focal of one and listened at the focal of the other. No bass - gone like through a HP filter. Why?

Hello Everyone,

I am looking for the Schematic for the L1 preamp if anyone has it, as I would greatly appreciate it. I am needing to replace the transformer, and I need the specs for it

Thank You.

Jonathan

I just ordered an infrared sauna unlike traditional saunas these only get to about 140 f . I wonder if I could use a pc monitor or laptop in an environment like that Oh I know if it would work there normal life spans would be radical shortened but could I still expect a couple of hundred hrs life span instead of the normal several years. I am definitively not worried about voiding the warranty !

Hi,

I'm currently using my "full" range electrostatic loudspeakers combined with TL woofers. I use a dsp to switch from esl full range mode to esl + TL woofer mode, depentent on the music I listen to.

The TL woofers are actually a 2-way exiting loudspeaker DIY model:



As I only use the mid / bass driver, I would like to add another fold to the TL design in order to make the design less tall. I'm wondering if this would be possible without changing acoustical properties / sound?

Hi friends.

I have a dude.

Is possible to do an amp with this two tubes ?

An amp with D3A KT88 tubes.

I have +B 480V and i have two tubes each one, and 4.2K 40% SE Output Transformers.

Thanks.

Take care.

My Sherwood integrated amp had a meltdown and I have got it up and running but I had to replace two diodes in the power supply. I replace diodes labeled SM334 with IN4007's. Now the voltages for the B+ are high by about 50 vdc. I replaced all the filter caps and resistors out of speck. I couldn't find any reference on the SM334 so I was wondering if the IN4007"s were not a direct replacement. I have a service manual but it gives no info on these diodes. Any help would be appreciated, Tom??
😕

WTD: Jeff's cloned J2 pcb boards

I am looking for a pair of J2 cloned pcb boards that Jeff ran a group buy some time back. If someone is holding on and do not want to build please PM me and I would prefer shipping within US.

Thanks

Hi at all
I have just bought one INT-150 and isnt that a nice amp ?
I think so.
It is intended to drive my two original ESS amt 1C who i bought from new so they are mostly original apart from that i have replaced the internal and external wiring with solid silver wire (teflon flat cabel from an ancient IBM computer made with multicore solid silver) like 2 x 2,8 mm2 (no terminals just directly wired to crossover).
And silver from the crossover to the Heil and the Bass and then i removed the passive bas and filled up with longhaired african "Danish compatible" sheeps wool that really works.

(No sry I cant tell you where my store here in DK got it (he wont tell me) and no there is no more to get, that works it was bought for some of his own developed speakers and he cant get anything like it anymore)

And boosted the bass with 3-6 db at 30-35 hz to lift the missing bottom a little.
And they are fantastic (I think) just the Heils are in need now of replacement diagramphs after like +30 years service i really have to complain to ESS 😀.
ESS AMT-1 AIR Motion Diaphragm buy at hifisound.de

So I have 2 questions to you where hopefully someone can help with an answer or input :

Is it OK to bridge two INT-150 to get the needed +400 W to the ESSs w/o spoiling the quality of the sound ?
Have anyone tried to bridge them to drive similiar loads (like nominal 6 Ohms)
Any input here is appreciated it could also be for the X150.5 that contains the same output stage as far as I have understood.

And finally anyone with experience with quality etc. when replacing the amt diagramphs.
Yeah I know its the Pass Forum but bear in mind that Nelson Pass worked for ESS back in time so maybe I am forgiven ?
or pls. help me find right forum.

Hello All,

My knowledge of tubes is very very limited, so I would appreciate some help with a preamp problem.

I built an Assemblage L-1 preamp from a kit back in 1999. It has performed beautifully since I first powered it up. I leave it powered up 24-7. This is a line-level only preamp with a single tube that is shared for both channels. In 2011, I did the first tube replacement (Sovtek 6922). A few months ago I noticed some microphonics in the right channel. I did some measurements with a QA401 and found the right channel gain was about 0.3dB lower than the left channel.
So, I replaced the tube with a Genalex Gold Lion E88CC/6922. The gain is now identical between the two channels but has much more variation across frequency. The first figure is before the tube change while the second figure is after the tube change. I also measured THD across frequency, and, on average it is about the same for both channels (0.01% to 0.02%), but does show a little more variation after the tube change . My question - is the variation with frequency simply a function of the tube such that a different brand might perform differently, and hopefully with less variation.

Thanks in advance for any help.

ceulrich

I have tried many thing to get the OPA544 to work as a Gainclone, and have given up.
I went back to the datasheet and found that the THD graph was quoted into a load of 15Ohm, and it looks prity bad at that. Into an average speaker this thing will and does distort to hell- and its nasty, peaky distortion at that.
I finally got it working to a just about acceptable level by having a 10ohnm resistor in series with the output- there is still noticable distortion.
I just hope I haven't damaged my tweeter !!!

Shoog

I have for sale my ian canada fifopi ultimate and two crytek clocks, 22 and 45mhz.
Also a raspberry pi 3 b.

ian fifo ultimate: 110 €
crystek clocks: 20 € each one
Raspeberry pi 3b: 29€

prices in Europe include shipping registered with tracking number.

Gentlemen,

I see that quite a few members from Argentina are contributing here.
For somebody in Buenos Aires I am looking for a local manufacturer of
SM power supplies.

The task is to replicate something like a TDK Lambda 28 V 9 A supply of
the DTM250-D series, these are according to regulations for medical use.

The supplier must be able to deliver quantities of the supply and preferably
cheaper than Lambda. Lead time of the TDK factory is about 11..13 weeks.
At the moment it is only possible to order small quantities from the usual
vendors.

I do however not expect that a factory like this exists in South America
(btw is this a common economic area without custom duties ?) but who
knows.

Thank you for useful replies. I do not intend to be bashed, was just asked
for assistance.

Have a alpine 3544 that won't turn on. No response what so ever when power supplied. Need the schematics / service manual. Thanks alot

High school electronics was long ago, so bear with me.

I'd like to build a summing box that accepts the outputs from a PC soundcard and mixes them down into a single mono signal that I can feed to an amp which drives an array of tactile transducers. The application here is a racing simulator cockpit.

Aside from driving the tactile transducers, I am splitting the analog signals from the soundcard with Y cables and thus also feeding a Klipsch 4.1 ProMedia speaker system.

Right now I am combining everything for my transducers using a Behringer analog mixer. It's big and in the way and channels are starting to fail. So I want to replace it with something more compact that I can hide away. I don't need the faders or other features of the mixer. I just need a way to combine the 4.1 audio into one mono signal. Preferably something small I can tuck out of the way.

My thought was to build a simple passive summing circuit using resistors but I am calculating that I will lose maybe 15dB or more of the signal and I'd need some kind of preamp to bring it back up closer to line-level for it to be useful.

My next thought is to include an inverting op-amp to bring the gain back up, and maybe include a capacitor in parallel with the feedback resistor to serve as another bit of low-pass filtering.

The transducer array is 4ohms and can handle 80W rms. Right now I'm driving them with one of the little crappy amps that came with the transducers as part of the Aura Interactor toy back in the 90s. It's probably not putting out much more than 10W without starting to break up in an unacceptable way. So the other thing I'd like to do is replace that toy amp with something that has a bit more clean power.

The amps I have been considering are ~ $15 USD and based on the TPA 3116 chip. Anecdotally, these can make ~ 50W rms into 4ohms with < 1% thd from a 24V 4A wall-wart.

My next thought after that was why not put the summing amp and power amp in the same box and power everything off the same power supply?

What I am hoping for from you folks is some guidance about

1. Is this idea practical? Is there already a design/part list for something like this?
2. What op amp should I be considering for the active summing circuit? I'm really clueless about how to determine that part of the puzzle.
3. Are there other power amplifiers using other chips that be more suitable?
4. How much trouble will it be to run everything from one wall-wart?
5. Am I going to have trouble if I wire everything point-to-point? Or maybe even just plop it down on a breadboard? Making a pcb for this is probably going to take it into the "more trouble than it's worth" column.
6. What am I not thinking about?

Thanks for reading and any guidance you can provide.

Hi 2 Q's
I have been given a Carlsbro Cobra 90 Keyboard 3 channel combo with reverb
the reverb was not working. However if you bumped cabinet hard you got the reverb crash from the springs banging and so crudely this proved to me the output was working. Took cab apart and found it only had the output phono (from rev) lead connected, the input signal was detached from the board but rca phono still connected reverb input
I can't see on schematic obtained these connection points, what i can say is the screen and signal for the output from the reverb are connected to marked 2 for screen and 3 for screen. Points marked 1 and 8 are for the disconnected cable
can u say which is which. Rev Accutronics 4BB3A1B
2nd q if i may i took continuity meter setting and just idly checked points then the reverb itself. on the input end i got continuity beep but instead of 0 i was reading 22 to 24, but other 'end' which was t? on input damagedhe output from rev and read 189 to 191 no beep is this right?

Hi, I dropped one of my small monitor computer speaker on to a slate floor and now the sound from it is distorted.
I googled the driver ,5" but nothing coming up in a search, so my question is, what could i replace this driver with...of course i will replace both to match, maybe i can improve sound also with new driver?.
The Tannoy box measures 8.5"H X 6"W X 5.5"D.
Also i am using an Amp to drive speakers
Thanks

Hello all from central North Carolina.
I've been fascinated with diy speaker builds for quite awhile and I think it's time to finally take the plunge and get right into it.
It's all new to me but I'm eager to start soaking up information and playing around with some builds.
I've got a complete cabinet/woodworking shop at my disposal. We've done refinishing, veneer repair and built a few sets of speakers for customers. My only real limitations are designs and money.
My first project for myself will be a subwoofer system build for my small den home theater and listening room. Second post to come shortly in the subwoofer subforum.
Along with some speaker stands to mount my old SVS SCS-01 LCR to create either a 3.1 or 3.2 system.
Looking forward to getting involved and hopefully gaining some knowledge along the way.
Thanks,
Nathan

I am aware of subscribing to a thread - is it possible to setup email alert for when a particular member posts regardless of thread?

Not stalking someone 🙂

Hi guys, simple question.... Is a crossover for a compression driver and horn the same as a cone speaker? The reason is that I tried a crossover slope that looked good in xsim but the recorded sweep looked nothing like what was predicted. Hardly any roll of for a 2nd order...

What do you think?

Cheers

Hi

Hi all,
I like to build a pair of enclosures monitor speakers, Fonken type, I choose one that use the Fostex FE127e drive unit which is discontinued by Fostex, would anyone point me the substitute of this drive unit?

Thanks in advance.
Joaquim Bento

Hi guys,
New guy here.
I have a problem with a 2.5 year old Yamaha RX-797 Receiver.

All of a sudden, it will not produce any sound unless the "pure direct" button is enabled.
Essentially, this bypasses all tonal control, balance control, etc.
With the "pure direct" enabled the amplifiers work wonderfully, but with no control of tone/balance of course.
I would guess this indicates a problem in either the tone control sub-board, or the "pure direct" sub-board?
Mother Yamaha cannot even recommend a repair facility, or even let me know if there are any T.S.B.'s on this problem.
A Google search yielded a few other people with this same condition in their RX-797, but so far no one has posted any replies on if this is a known problem, etc.
Anyone?
Thanks in advance... 🙂