Hi friends
the much praised Iron solder being out of stock, I'm asking for a recommendation: What solder is best suited for SMD?
Thank you!
david

I just finished building a set of F6 amp (buffered version, with source degeneration resistor), since I have balanced front ends so I am using a LL1540 transformer to convert the balanced signal to unbalanced following the datasheet and directly connect the output to input of F6

The problem is, almost no sound, or more like the input is shunt to ground. So I did a little debugging.

1. I bypass the transformer and used a signal generator to drive it. It works, sounds alright and the scope gives me nice waveform and a gain around 15db

2. I left the amp power off and drive from transformer input and measured output(still hooked up to input to F6). It still looks fine, with an insertion loss around 0.6db which the transformer specifies as 0.5db.

3. Then I powered the amp on, then, the output from the transformer(input to F6) drops to almost 0. So I redid step 1 with various signal source resistance and calculated a input impedance around 10kohm, less than expected but still looks fine.

So now I am confused, could someone enlighten me what did I do wrong?

Hello,
I have a custom rotary mixer with 50k log taper pots with the unity gain at the end of the turn, 10 (5 o'clock), This is not very comfortable for me so I would like to change the unit at 7.5 (2 o'clock). Is it possible?
Thanks.

Hello everyone!
I am planning to upgrade my self made portable "boombox" with some better speakers and amplifier, and i already have quite a good idea on what to get but i'd like some opinions from who wants to help me with some advice 😀

First of all, the box is already built (attached picture). It's a 10 litre bass reflex box with two, let's say full-range, speakers that share the said 10L, and two ports that tune the box to 58Hz IIRC (i made it some years ago). The speakers were salvaged and are just some random "eongchang" 4 inch 5W drivers that came off an AIWA LCX110 microHiFi, so nothing fancy really.

The box already has a 4s li-ion battery, so 14.4V nominal.
For the amplifier i'm gonna use a tpa3116 based aiyima board with tone controls and bluetooth. This means that the maximum power going to the speakers will be around 30 watts at 1% THD+N, plus i'll have some sort of EQ.

As for the drivers, what i'm looking for is a pair of woofers and tweeters, keeping the budget a bit low (possibly less than 100€ for everything, crossover included) but still managing to get a good sounding system. The woofers can be both 4" or 5" and i need a good compromise between sensitivity and bass extension, as the speaker is battery powered.

Speaking of the woofers, my best bet for this enclosure are the Sb Acoustics sb12pfcr25-4, as they have an acceptable 87.5 dB sensitivity and are quite cheap. I've simulated them in Speakerboxlite with my box specifications (so two drivers into a single 10L ported enclosure, Fb being 58Hz) and the frequency response shows an F3 of 57, F6 of 50 and F10 of 44Hz. How do you think that would sound? I personally am new to speaker modelling so i don't know how these numbers translate to actual listening, if these would have good bass or be a bit lacking.
I've also simulated the sb13pfcr25-4 but it looks like the bass would be worse on these in the same box.
I checked some other drivers as well, but the SB12 look to be the best compromise between sensitivity and bass extension.

For the tweeters my possible choice are the LaVoce tn100.70: they're cheap and with a second order crossover (and maybe a 1.5dB L-pad as they're 89dB) they should do well with the SB midwoofers, or at least it looks like so from my simulations with XSiM and the crossover calculator spreadsheet.

I already tried designing the crossover but i'll wait until i decide myself on the components to purchase before asking you further information 🙂

So, in the end this is what i have in mind for now, and i hope to hear some opinions from anyone willing to help in this upgrade project. I hope i didn't violate any forum rules in the post (if so, please let me know!)
Thanks in advance to everyone 🙂

Hi

I want to use the following transformer for the SSE board, and I am wondering how I should wire it up. Very new to this, and my confusion about the high voltage wires - so wanted to check.

AS-4T360 - 400VA 360V Transformer - AnTek Products Corp

View attachment 900708

My thought is to connect the WHITE and YELLOW wires in the two 360v in to get 720V, and connect the YELLOW(0V) and WHITE(720V) to T1-RED and the same WHITE(0V) to T1-RED-YEL.

View attachment 900712

Is this the right way to think about this?

Thanks
Mark

The new Apple AirPods Max claim to offer stable surround sound, as you move your head the surround perception adjusts accordingly using movement sensors.

AirPods Max - Apple

Looking forward to the day Apple et al get tired of bad recordings making their audio products sound bad, motivate them to fix the sources.

Hello,

Can please someone clarify two things with regards to IST coupling in the following common-cathode configuration.
1. Do I need grid leak here? I've seen various opinions on whether it's better to have IST staring at ~infinite grid or rather have a fixed load of, say, 100k.
2. Do I need a grid stopper here? Or would IST secondary DCR serve the purpose to prevent oscillation/low pass?

Thanks,
Igor.

Hi,
Ive just put together an amp / preamp combo. Every thing sounds great but it has an audible hum when the amps input cables are connected to the preamps outs, the hum is not effected with the volume, its a set volume.
The weird thing is if i connect either the left or right channel only via the cable theres no hum?
Its only when both channels are connected.
Anyone got any ideas?
Regards
Mike

Does anyone have any drawings of this amp (old).

I've got it operating but have a hiss in the output.

There are 2 daughterboards on the output. I assume the first is the PWM creator and the second is the final drive?

I have one low side output in and one hi.

Low side is getting hot. If I remove the "PWM" board it does not get hot. However drive looks ok when board is in.

The A series VOTT bass cab seems very interesting. But is it a bass horn? It looks like a front loaded high-mid horn with a huge reflex cabinet on the back of the driver.
So how does the bass keep up with the midrange? What is the typical cross over frequency?
How does it compare to a Karlson or Karlsonator?
Thanks. I am about to build something for my 15s and the VOTTS are rather large but what the hell... I find it hard to deside which design to go for. High efficiency and dynamics are pri 1.

Hi, appreciated for help with this... no joy searching internet.

I acquired this sub DOA and through testing, i have figured out the thermal fuse blew in this transformer. I would love to get it going again, but no idea how to get same transformer or at least equiv enough. This has been a learning process for me at each step and appreciated for some inputs from experienced here.

Marked:
Ten Pao
TP76u57E

Much appreciated! Al

Thought you guys might appreciate the aesthetics (not to mention the sound quality) of this one.

The components are tightly fitted into a beorecord 5500 housing. The components are:

+ Intel NUC D54250WYK Core i5 4th Gen Windows 10 Pro 120GB SSD 8GB RAM

+ 1080p touch screen

+ 12v 2amp power supply for display

+ 19v 5amp power supply for NUC

+ Firefly Cobalt USB DAC

+ Micro USB to USB and mini HDMI to HDMI cables for display connection (USB for touch control).

+ Custom DIN to firefly audio cable for connecting to the CD input of Beomaster 5500.

I have four 8200uF @ 50V caps.
I have one 15000uF @ 35V cap.

All test good and no physical deformities. Date code is 1993. I pulled them from a big unused power supply at work a few years ago.

I have two big inductors as well.

$10 for all plus a few dollars postage.

Two tube shield assemblies for sale.

$5 plus a few bucks postage.

I folks,

I'm not looking to open a can of worms on the supposed sonic advantages/disadvantages of mains conditioning.

Let me explain the situations: I moved to a new city in the last year, and since getting here every largish transformer I have hums. The toroid in my SS amp hums, an EL I'm using in a new amp hummed a bit when I tested it, I can hear the transformer in my Desktop computer hum, and the power amp for a home theater system hums, and there is now more background noise and a worse power off thump than there was before. These things are all in the same room, but the hum follows any of them around the house.

All of this humming is getting close to driving me insane. We also have a small aquarium pump elsewhere in the house that vibrates, so much so it has kept me awake some nights. I replaced one pump on warranty, thinking it was the pump, and then tried another brand, all of which were well regarded for being quite and smooth. Most of the time it is very quite, but sometimes it is extremely loud, I've noticed when it is being loud the Torioid in my SS amp hums worse. Both of them are loud right now in fact. CFL's seem to hum sometimes too.

My fiance hears the humming too, so I know I haven't just lost my mind. In fact, she though she was going crazy until she mentioned it and I told her I could hear it too.

So from some research I think that there is likely DC on the mains, quite a bit, or that there is some signal at higher than 60hz. Or both. Unfortunately I only have a DMM, so i'm not sure how to test for either of these. However, I'm going to be moving a lot over the next few years, so it occurred to me that I might as well just build something that deals with both.

I've found plenty of circuits for DC blockers, seems like some diodes and large capacitors in parallel is the way to go for that.

As for dealing with non-60hz signal that isn't into the RF range, I'm having trouble and looking for suggestions.

Additionally, the mains voltage is not very stable here, and rather high. Normal is 123, but I've seen it as high as 125 and as low as 118 when testing outlets. I've been getting more into vintage gear lately, so I was thinking I might want some a 117 or 115 outlets on my "power station". I may just buy a variac (which would probably hum too ), but what are some other solutions and ways of dealing with the unstable voltage, usually it will be go +/- 1v a few times a minute, with occasional big drops and spikes that aren't related to local draw.

Speaking of testing outlets, I've had to replace a few because of faulty grounds, I was thinking of incorporating some sort of fault detection circuit and indicator LEDs on my power station, any suggestions there as well?

I've got about 4x as many power bars as I actually need around here, so I have plenty of outlets, and appropriately rated switches and breakers to scavenge.

Sorry for the long rambly post- I didn't sleep well last night. Can you guess why?

I'm working on this marantz 510m and in one channel the DC goes really high on startup before stabilizing. It swings positive to around 30V. I'm still running it on the dim bulb tester with a 60W bulb. The other channel doesn't do this. There's no speaker protection, and it pins the meter, so it needs to start up better than this. It takes 20 or so seconds to stabilize. I haven't changed much on this board. The electrolytic caps and the emitter resistors. The outputs have all been changed to onsemis. I've swapped driver boards between channels as they disconnect from the outputs/drivers and the problem follows the driver board.
When it settles it plays fine.

I've never seen something swing this hard when powering up, how can I troubleshoot this?

I have the following drivers for sale. All were purchased brand new over the last 6 months and used very little.

SOLD ** Aurum Cantus 12” AC300/75C2C, $240/pr, qty 4 - Reduced price ** SOLD

Paypal included in price, shipping at buyers expense.

I have the following drivers for sale. All were purchased brand new over the last 6 months and used very little.

Mundorf AMT21CM2.1-C, $230 , qty 1

SOLD** Mundorf AMT25CM1.1-R, $620/pr , qty 2 **SOLD

Paypal included in price, shipping at buyers expense.

I have the following drivers for sale. All were purchased brand new over the last 6 months and used very little.

Audax Aeroget 5.25” HM130Z0, $80/pair, qty 2 available (1 pair SOLD, 2nd pair still available)

Eton 5.25” 5-212/C8/25 HEX Symphony II, $90, qty 1

SOLD ** Aurum Cantus 5.25” AC-130F1, $70/pr, qty 4 ** SOLD

Paypal included in price, shipping at buyers expense. Drivers shipping from Michigan, USA

hi , all

I would like to make Aleph 5 amplifier for myself .

can you advise me if it is possible to make a stereo amplifier with only one transformer?

also i have a question about a 2.2mH coil in power supply . I can do it with aircore or metal core ?
Which will be better ?

Regards !!!

Howdy,

I have a circa 1988 Yamaha RX-700 natural sound receiver I purchased brand new in High School. I've been using a pair of vintage Altec Lansing 83 (100 watt, 8 ohm) bookshelf speakers in my 13' by 16' living room. Not great sound, for sure. I'm trying to decide which of two options I should chose, both are used DCM speakers which seem to be highly regarded, especially the TF-600.

But, is my amp too under-powered for the TF-600s? Should I go for the CX-27s instead? Thought I'd ask the experts!

My Yamaha receiver has the following specs:

Power output: 65 watts/channel into 8 ohms stereo
75 watts/channel into 6 ohms
Speaker load impedance: 6 ohms to 16 ohms
frequency response: 20Hz to 20kHz

Option 1:

DCM TimeFrame 600:
recommended amp power: 10 - 250 watts
max power handling: 250 watts RMS peak
6 ohm nominal
frequency response: 30 Hz to 20kHz

or option 2:

DCM CX-27
recommended amp power: 10 watts to 150 watts
max power handling: 150 watts RMS peak program
6 ohms nominal
frequency response: 35Hz to 20kHz

Good morning,

I'm looking how to achieve parametric EQ driven by serial commands (issued by an Arduino).

I wouldn't like to process the audio in the Arduino because I want it real time and high quality, something that I think, Arduino can't perform.

At this time, I know the TDA7317 for graphical EQ with serial commands but it is not parametric.

I found the LC75281E but didn't found any example schematic and I didn't found where to buy it (discontinued product?)

Is there any chip or DIY kit allowing me to add parametric EQ into my circuit and allow my Arduino to drive it?

Thanks in advance.

Hi
Where can I get repair schematics for a Sunfire HRS-12 who sounds like a ”humming” bird right now ☹️??
Best regards
Michael

Hey guys!

My friend got himself a new microphone, a Sennheiser e935.
While he loves that mic, he wants to connect it to his iPhone, or laptop via jack.

I want to build him a preamp, which amplifies the signal coming from his mic to the maximum of the phones/laptops input.. Using batteries.

I was wondering if there is any op amps which I could use with a single 9V battery (Or maybe 2 AA batteries (3V)?)

I have found a schematic on Elliots page (attached)
Do you think this could be enough for this case? (Of course with variable gain [R6 = pot])
How could one limit the maximum voltage output for not destroying the phones mic input?

Thanks for your help
Daniel

Hi all,

Thinking about build one of these, a 12 faced omni.

First driver that comes to mind is 3FE25,
because I already have 4, and 8 more would only cost me another hundred dollars.

I'd like to get reasonably flat freq response from 100Hz, to as high as possible, without excessive low end boost.

For any of you folks who have contemplated a dodec, any driver recommendations come to mind ?

And did you consider porting them?

thx 🙂

What Is Wrong With This DAC? There is significant distortion and it measures far worse than the LJM CS4398.

Attached Picture: Measurements of CIRMECH CS4398 DAC With NJM4580D.


Does anyone else have this DAC? Has anyone else measured it? FYI: I remeasured my ES9028Q2M to make sure I did not have a problem with my ADC.

I'm having great results with the Renditions; can listen to them for hours on end and they always make everything sound just a bit more interesting.
That said, wanted to try the Wavecor tweeter version, and at the same time PE started supplying Wavecor.
Well all good, and had plenty of supplies to make a pair of MTM's with front port/BB boxes; similar to the Renditions with the larger Wavecor tweeter.

Now the stumbling block, no xo schematic.

Any ideas folks?


TW030WA11_12
[TWO30WA11-01]
Anarchy 7 inch woofer by Denovo Audio

**Boxes shown, no wires, xo, etc.

Closed

For sell euro 600,00 with shipment

MIRAND AUDIO DAC VERS 1. AK4490 V1
Dac Sounds exceptional and it's done as follow: SEE PICTURES
many pmlcaps in dac and shield pcbs.
n. 2 transformers, 1, RCORE 30 W & EI for XMOS separate supply
n. 4 separate supplies respectively for Xmos , Dac, Clock, with ultralow noise regulators, 2 x LT3045 ( Ivanov) , 1 KoSa (LT3042 with pmlcaps ) 2 x Mvralica, one for Raw another for Xmos
all snubberized with Quasimodo.
Modified Ground path.
New Ultra precision Crystal Clock NDK SDA ( the original quartz were " normal")
Please note n. 8 Mundorf Mlytic 10kuF 25 V
Dac SOUNDS DSD Direct (Original PCB can't) with Arduino soldered near Xmos ( see pictures) Arduino is programmed for modifies Xmos firmware.
nextgen rca Output wired with pure silver 24 awg
All AC and DC wire are Neotech UPOCC 18 awg copper wire

X250 recently develop hum problem, from the amp itself, not from the speakers. It only happens if running for more than 2 hr. If turn on, but in idle, nothing happens. Thanks for any advice.

Hi all

I got an old klipsch ksw10 subwoofer today. It is not working so i opened it up. The problem was quite clear quickly: tehre seems to have been a little burnout, and two parts have been removed. I can not find the schematic online, so i wa shoping someone can help me with identifying these parts:



I hope someone can help!

No longer for sale

Only used for some testing so as good as new, decided to go with subwoofer modules instead of seperate amp & filter

2*IRS400SMPS amplifiers with integrated power supply

New price was about 275 euros for the modules and additional tax. Which by itself is a bargain for 2*400 watt amps with power supplies

Hey,

I have a couple of questions with regards to phase and doing XO simulations with REW measurements.

Using a calibrated USB mic and the "acoustic timing reference" option turned on in REW - will I be able to accurately use the phase data in the exported FRD file?

If not, then I reckon I can at least use it to measure the time delay between each driver? Like so: Driver time alignment

Hi,
I would like to ask how to match JFET’s like UJN1208k for using it in parallel as output devices ?

I compiled differents desings and added my own to create a nice little Soft Start and Standby circuit that can be usefull in building your Aleph.

Here the features:
The circuit is turn on by a main AC switch, possibly on the back of the amp then the softstart activate.
The softstart is the Elliot Project 39 version. A nice feature is that a small rating external switch can be used to turn on/off the amp from the front, it connects instead of a jumper on JP1.

Two nice additions are a safety feature of the soft start, a thermal cut off fuse, that will be mounted between the power resistors. It prevents any catastrophic failure.

The circuit can also power two 12Vdc fans. Their speed can be reduced by adjusting the value of R10. The Fans can be turn on/off automaticly by the standby mode or on continuously using JP2

Then working on the same 24V supply is the standby circuit. It is operated from a front mounted switch/led assembly or by remote 12V trig on the back. It provides these features:
-Auto-reset at start-up, standby mode activated, led inside power-on switch is flashing.
-Two DPDT relays can be used to provide the standby functions. I'm planning to short the inputs and select the lowest channel's bias setting in standby. The JP1 jumper can select the relays state in standby, On or Off.
-Press the SW1 switch, and the amp turn On full bias and ready. The SW1 led turn on continuously.
The momentary switch is well debounced and don't produce any false trigger.
-A 12V remote trigger on the back can activate the power-on mode remotely.
-A 12V alarm relay option. In case on an alarm inside the amp,
an external 12V will activate a rapidly flashing led.

The over-temperature cut off can be implemented using thermostat directly mounted on each channel heatsink, in serie with the main power switch and fuse, just before the soft start PCB. The digikey part number for the cut off is: 317-1085-ND
Thermostat, 75 DegC, Normally-Closed

I created a specific group for amplifier repairmen and those who are seriously learning on Facebook. I'm going to try and get it filled with knowledgeable people and make it a place where someone can ask questions without being made to feel like an idiot for trying.

That being said, anyone who comes in with a blown amp and just says "what's wrong" won't be staying long.

Also hoping to create a directory of repairmen so if you have someone who doesn't want to ship, they can be directed to someone in their area.

Car Audio Amplifier Repairmen

Hi all

Power supply mosfets blew in the amp. It has two transformers. Each transformer has 8 mosfets in all i.e. 4x4. So total of 16 mosfets. It has pnp transistor that drives them blow also. And I cant see the value of it. Can anybody suggest good driver pnp transistor?

Hi


This TSL 100 I am working on has a very high plate voltage. Without any power tubes in, the plate voltage reads around 535V. With the tubes in, the voltage drops to approx 505V. Is this plate voltage acceptable. How can I bring down the plate voltage. Please assist.


Thanks

Hi all
Would like to build solid and high quality monitors. Just for every day background listening. I run my main towers when I need higher spl and more bass.

I have heard pretty good about Satori MW16P midrange and decided to use these.
I am openminded what tweeter should be very good match to these midranges.

I prefer tweeter which is:
*price range up to 250usd
*musical
*not fatiguing
*warm
*lively

Some suggest directly TW29DN - but maybe anything else that fits to my criterias?

Midrnage: Satori MW16P Black Egyptian Reed Cone Woofer

Hi. An other little project of mine. I have a very nice Lumi U1 mini music server. The only real difference between the U1 mini and the full U1 is a less fancy case and the use of a little 12V switching power supply instead of a full discrete one into the bigger U1.

So there is an easy way to reach for the full U1 performance, replace the switching power supply... There are a few commercial offering out there, but they are rather expensive. I made my own little version, that fit into an Hammond enclosure. It uses the same LDO voltage regulator as the Lumin external power supply.

My version use a standard rectifier, or like I will do, use a 'perfect Bridge' active rectifier, then a CLC filter, the the LDO 12V regulator. There is provision on the PCB for an external power on switch and front ON led.

The original Lumin SMPS supply is a 12V, 0.7A. Mine will be limited/protected at 12V, 1A.

There is provision on the board to use a small split core transformer from Triad, simply because I had one in stock, but you can always wire an external toroidal transformer if you wish. No need for anything fancy, any 12V/1A transfo will do. The PCB supports dual primaries 115/230V transfo.

Anyway I'll have a few left over pcb from my prototype. If interested they will be 25U$ each + Shipping + 3%Paypal fees.

I'll test my prototype first, then I'll will confirm the parts list and schematic.

Naturally you will be responsible to install your supply with your own Lumin, and I cannot be responsible for any damage you can do in the process. Thanks for your understanding...
SB

Hello,

I plan to build a custom enclosure for a dac-streamer.
I have a few questions:
The PSU is a SMPS: how can I isolate the dac part from the PSU: should they be on the same horizontal plane? One above the other? Should I put a copper separation between them ?
Thank you!

I am looking for a possibility of isolated mounting of 6 pcs DO-5 zener diodes one the same heat sink.
The diodes looks like this versions:
1N3309B Z- DIODE 10V 50W DO-5 | Capcomp Shop
NTE Elektronik nte5247ak Zener Diode - 6.8v 50w do-5 5% Cathode Case | eBay
Actually there should be heat sinks for it with one surface accordingly TO247 and one surface with a hole of 5mm Ø

The reason for that is the follow:
In a preamp with shunt regulated power supply there must replace high power zener diodes in an electrical isolated outline like that one from this rectifier:
KBPC3510FP pdf, KBPC3510FP description, KBPC3510FP datasheets, KBPC3510FP view ::: ALLDATASHEET :::
go to the first attachment.

The replacement parts of this zeners are only available in an electrical unisolated DO-5 outline, but I want to fix five or six of this electrical unisolated devices of this zeners on the same heatsink (the last image shows only a temporary solution, which I don't like).

Thanks for an advice.

How many amps does my power supply transformer need to be to power a pair of the $1.99 LM1875 kits form China? I will be powering the amp with 24 volts.

I want to know a replacement for the above mentioned zener diodes. I don't know the naming of the associated outline, but it looks similar to those under
VS-GBPC2508W | Vishay VS-GBPC2508W, Bridge Rectifier, 25A 800V, 4-Pin GBPC-W | RS Components
but with only two connectors.
The power zeners (7 pcs) are in use in a voltage regulator for creating the anode voltage of a diy tube pre-amplifier with ECL-86
Thanks for posting a URL for a data sheet.

Good morning,

I'm looking to design and build some DIY line array active speakers for small live use (200-300 peoples, indoor).

I think starting with 10 inch raw speakers, and to put two of them on each cabinet, with one compression driver.

But my problem is all raw speakers in my country doesn't have a precise documentation (mostly china stuffs), so I don't know its effective RMS power, effective frequency range, ...

How can I proceed to evaluate the best amplifier circuit power I can use to achieve my need? As we will use it mainly for rock/prog metal, I wish to achieve the maximum quality.

Thanks in advance.

OK, I think I've made this work. Multiple Tian stability plots across the signal swing. Thanks to jcx and fas42 for assistance.

I have a 250W CFP output stage I'm working on. I wanted to break the CFP local loop to check GM & PM at several points on the output swing, from -80V to +80V. Here's what I did.

Nested .step sweeps:
.param dcin=0 prb=0
.ac dec 100 1 1e9
.step param prb list -1 1 ; Tian loopbreak probe V1 and I1; set prb=0 to turn off probe
.step param dcin list -78 -40 0 40 78 ; run Tian loopbreak at each of these voltages

One .func in the plot.defs file for each of the dcin values:
.func stb1() -1/(1-1/(2*(I(VI)@1*V(OUT)@2-V(OUT)@1*I(VI)@2)+V(OUT)@1+I(VI)@2))

.func stb2() -1/(1-1/(2*(I(VI)@3*V(OUT)@4-V(OUT)@3*I(VI)@4)+V(OUT)@3+I(VI)@4))

.func stb3() -1/(1-1/(2*(I(VI)@5*V(OUT)@6-V(OUT)@5*I(VI)@6)+V(OUT)@5+I(VI)@6))

.func stb4() -1/(1-1/(2*(I(VI)@7*V(OUT)@8-V(OUT)@7*I(VI)@8)+V(OUT)@7+I(VI)@8))

.func stb5() -1/(1-1/(2*(I(VI)@9*V(OUT)@10-V(OUT)@9*I(VI)@10)+V(OUT)@9+I(VI)@10))

I think I'll start a thread on this, so others can see it, cause it's useful.
Here's the schematic and plots for your viewing pleasure:

Hello!

New forum member here who is in the process of building my first loudspeaker pair, separate thread regarding the build found here: Studio 3-way reference monitor build, need help choosing drivers

I have been reading a lot on the subject in recent weeks/months and I have been sharing this new found interest with my brother who has responded in kind and now we are 2 really interested persons who would like to really get serious when it comes to loudspeaker design. I am currently studying to become a medical doctor, which is not really applicable to loudspeaker design (if you're not counting human hearing, maybe there is a future for me in studying and advancing our knowledge of human perception of sound?? Any input/thoughts/available paths forward regarding this would be greatly appreciated).

My brother has finished his phd in chemical engineering/material design. His graduating work (not sure what you call this in english speaking countries? Graduate work/project?) was concerned with synthetisizing novel polymers based on a set of wanted characteristics.

We have now developed a vision of using his knowledge/skill to develop new materials for loudspeaker drivers and loudspeaker enclosures, materials tailor-made to the needs of the frequency range in which the driver/enclosure operates.

Imagine a midrange driver that utilizes a tailor-made membrane-material for its specific frequency range which results in perfectly matched characteristics resulting in frequency response linearity and extremely low levels of distortion. Then imagine using this same material for the enclosure for this driver. Then imagine using this same methodology for all drivers in the design of a complete/full range loudspeaker. Maybe there is a possibility of creating something great sounding and economical?? I can specify what (modern) techniques of polymer synthetization we are planning on utilizing if there is an interest in knowing more about the potential of polymer materials.

I would be extremely grateful for all input/ideas/information pertaining to our quest. What is the function of the membrane of a loudspeaker? What is the source of its inherent structural instability (break-up etc.)? How is this instability related to the self-oscillating frequency? How is this related to the molecular make-up of the material? What would be the ideal material characteristics of a membrane for a specific frequency range of a loudspeaker driver?

Any sources (books, links) will be gladly accepted and researched, any insight/input/ideas regarding the topic is extremely welcome!

What would be the ideal loudspeaker membrane/enclosure material? Discuss

I have an audison AV12 in a very small, 18l vs 20 reccomended.


heres the TS parameters i pulled w dATS


Re 3.66
fs 39.4
vas 93.09
Qes .74
Qms 3.55
Qts .61
Le 1.47
EBP is 57


Im running about 220w into it in the box and its fat below 100hz to 20 hz in my honda Accord


Thinking of trying it in IB sice according to hornresp i would gain about 13db on the same power and still have excursion to spare.


Can anyone recomend something else? space available is 32"w x 15"h x 16"d gross


Priority is low frequency extension so i dont mind a large box since hoffman says so!


I built the little shoebox so icould get more tha the 6x9s in the rear deck.

I have an ART SLA-1 (stereo class AB power amp) and the stock fan is noisy. I want to replace it. I'm not an engineer, but have replaced many noisy fans in computers. Apparently it is a 12v 40mm x 20 mm fan. Should this one work?

Silenx

Here is the original.

Thoughts??

P.S. I just took out the original fan; it's made by Bi-Sonic, and is a DC brushless fan, model SP402012H, operating voltage 12V (10.2 - 13.8), current draw 0.16A; power consumption 1.92w. The Silenx specs are: operating voltage 8-14v; current draw 0.03A; power consumption 0.36w, so that all seems fine. What concerns me is the Bi-Sonic is 7000 RPM with a Flow CFM of 8.53, and the Silenx is 3000RPM with a Flow CFM of 6. I don't drive this amp hard at all, so I don't expect it to ever get that hot; will this "quiet" fan be strong enough??

I seem to remember someone coming up with some reason not to use steel for hi-fi audio enclosures. Does this ring any bells with anybody?

I have a pretty nice steel box from the junkyard but I wouldn't want to do anything counterproductive towards sound quality.

Thanks

Bam

I am about to order plywood for my speaker project, a subwoofer assisted two way speaker, with BBC-style thin wall enclosure. When researching the subject I found that as far as panel thickness goes Harbeth/Spendor/Rogers (so BBC contractors) used from 8mm in two way monitors to 12 mm plywood for larger boxes.

Now, from my local supply I can order only 7 mm plywood, even though its just 1 mm thinner than BBC spec, its as much as 12,5% difference from 8 mm panels used in commercial designs. So how thin can I go? I know that reducing panel thickness will lower the resonance frequency of the panel, which is a good thing according to BBC's approach, but there has to be some limitation, otherwise people would be using 3-5 mm panels to push the resonance below speaker's passband, which I haven't really seen in forums.

My two way design will cross over to sub, with Satori MW13P-8 in a bass reflex alignment tuned to around 70 Hz. Given relatively high tuning for this driver and some 5-5,5l net internal volume, simulations showed that I can use 2nd order BW highpass at some 130 Hz to land at -6 db at 80-85 Hz, where sub will take over.

It would a be a floorstanding design simply because my wife doesn't approve speaker stands. It will be 108 cm tall by 22 cm wide by 13 cm deep, but speakers will only use top 33 cm, so this subenclosure will also act as bracing at around 1/3 panel height. I plan to use 8 mm of alubutyl (2x 4 mm Silent Coat mat equivalent) damping on the inside to lower the amplitude of panel resonances. Front and back baffles would be mounted by screws, along BBC's design principles.

Your input would be much appreciated as I wanted to have panels cut this week to work on them during Christmas brake 🙂

here is one impedance question

Suppose we have one amplifier class AB that is specified to 200w @ 8R
suppose that we load this amplifier with a load that is 64 R ( 8 units of 8R in series )
wiring will be very short
units are relatively small and equal so theoretically 200w of power will be equally distributed to the nod and each unit will handle 1/8 of the power .

So electrically that sounds ok
Question is what will happen soundwise and this type of load effect in the performance of the amplifier
--Will slew rate change ?
--Will damping factor change
--Will frequency response change ?
--Is there a chance that amplifier will oscillate due to load is out of specs ?
--is there anything else that might go wrong with such an arrangement ?

kindest regards
Sakis

I knew these knock off solid state relays were under rated current wise but the common 40 amp models have a triac inside rated for only 16 amps!

It lasted a few years doing intermittent duty in my coffee roaster before shorting closed. There doesn't seem to be a middle of the road price point on these. Legit models are like $40 and fakes are $6.

Sold

Hi,

Looking for the Alps part number or equivalent of the push-button power switch of a Linn LK140 power amplifier? Linn no longer stocks it.

TIA

Vic

Hello smart folks!
I'm building a clone of the Audionote L3 Phono stage with tube rectifier and can't seem to find the needed wattage rating for the transformer or the the specs on the choke. Henrys, mA, resistance.
ANK Audiokits - L3 Phono Stage Mk2 Tube Regulated and Tube Output

Thanks!
Benjamin

Looking for understanding and making sure I'm doing this correctly. I've got a Pioneer GM-D9601 and 2 Pioneer TS-SW3002S4 Bass speakers, that I took out of my truck before selling it to a dealership. I will be hooking them up to my pc at home and powering it with an extra atx 500w power supply I had laying around. The speakers are 400w nominal power and nominal impedance is 4 ohms each. The speakers are in a closed box so I cant see how they are connected, but I believe they are connected in parallels because I get a 2 ohm reading when using my voltmeter on the two speaker wires coming out of the box, is this correct in how I figured this? and does this mean I treat it like 1 800w 2 ohm speaker? Or do I treat it like 1 400w 2 ohm speaker?

According to the amp manual the amp can output 800w at 2 ohms.

So following the formula I multiplied 800x2=1600
then the square root of 1600=40v, is this right?

Next, with speaker wire disconnected I will be rotating the gain dial clockwise until my voltmeter reads 40v. Is this right?

I will be testing with a 50Hz 0dB audio file from my computer and routing a rca cable from the 3.5 speaker out jack on the pc to the rca in on the mentioned amplifier. Let me know if there is a reason I shouldn't do this.

Also, I wasn't sure if I will need it, as I'm not sure how the amp will respond to the signal coming from the pc. But I have a LC2i that came out of the truck as well. Would it be better to put this in between the pc and the mono amp?

Thanks for anyone's help on this. Would hate to blow anything up. this bass sounded amazing in the truck, just want to put these to use until I have a vehicle to put them in (wont fit in the car).

IMG-0255 — ImgBB
IMG-0256 — ImgBB
IMG-0257 — ImgBB
IMG-0258 — ImgBB
IMG-0259 — ImgBB
https://ibb.co/q1pJchY
https://ibb.co/mFV2nxj
https://ibb.co/vVc6P29
https://ibb.co/gjfj29K
https://ibb.co/hd049HZ

for sale:
quad philips e182cc
tribute 20h potted CHOKE
jupiter VT 15uf 100v capcitors
quad of NOS Sylvania 6b4g tubes
6szt Siemens Sikorel 10000uf 63v
10 pairs of Elna Silmic ARS 100uf /50v capacitor (good on cathode)


make me an offer, 20-30% less than ebay prices.
I want to get rid of it quickly.
I live in EU

I just got a MC for my TT and now need a SUT. How do I design the one that will fit my system best? My phono pre is a DIY Hagerman octal Coronet with 43db gain and the new cart is the Denon DL-110.

Good morning,

I'm looking to design an amplifier with some digital based filters stuffs like driving TDA7317 EQ with Arduino Nano.

I usually run with Proteus to design & simulate electronic stuffs, but Proteus seems to not have a lot of audio stuffs. For example, I don't have TDA7294 chips for amplifying, TDA7317 for EQ, LC75281 for parametric EQ, ...

Is there any good software to design amplifiers / digital filters / ... other than Proteus, or is there any Proteus library to import most common audio chips in simulation?

Thanks in advance.

I am planning to build an open baffle "subwoofer" to complement my existing electrostatic speakers. The goal is to cover 30Hz to 100 Hz. Sensitivity can be as low as 86dB/1m. Each unit could have four drivers (space limit, one driver could be 6" diameter at most, they will be in line).
That means fs should be around 30Hz and Qts should be 0.7 to 1.2 or so. I think long throw is the most important requirement for an open baffle subwoofer.
What products shall I consider? (EU source preferred). Could any car audio drivers usable for the purpose?

Hi!

Is it possible to power signal relays from dual +V/-V rails instead of +V/gnd?
I think it should be possible, adding a resistor to the rail that switches it on or off. I use omron g5v1 and g5v2 series. the supply rails will be +/-16,5v.

¡Merry christmas!

Jay x

Hi,


WHat would ou advice as an electrical low pass cut-off for this driver, please ?


Mine is the NBAC but the NAC is similar. The H5 between around 1k and 2 k hz is worying me. My Due to the mid I wanted a 550 to 700 hz LP 6DB electrical, but I surmise the slope not to be stiff enough ? LR12 electrical instead perhaps, where according to you ?


Many thanks for your "poll" 🙂


The distortion measurment is from HifiCompass, I attached the 5.2V capture.
The filter will be passive with a zobel to flat the impedance.

Hello

For sale is a shigaclone mk2 black high grade version.. it has tentlabs xo, zfoil output resistors, tibis regulator on v3 and v4. This board was assembled by tibi. It will come with the sanyo sfp101 that was modified by tibi. Will come with 8v power supply and transformer, aluminum puck, and remote. The remote control is a little beat up but works..

You will need 5v power supply for v1 and v2. You will also need a capacitor for the c8 position (.1 uf brown cap in the pic is not included)

Asking $250.00 .. this has not been used for about 2 yrs since i started streaming.

Buyer pays shipping and PayPal fees

Thanks

i have a Precision Acoustics low power active sub that makes a sporadic noise (potato chips crunch like).
It seems to be an old model with the speaker to the floor and just a vent on front, maybe 100 watts.
i am looking some expert cues to start repairing.

Wears the tube out prematurely.

I had read about plate voltage leading to stripping/poisoning of the cathode only applying to voltages higher than about 600V. Not the case with my phono stage. All tubes had 280V on them without heat. After about 6 months, the tubes were "worn out". Where I expected 2 or 3 volts (cathode resistor), I got only 0.8V.

Maybe there is something to keeping HV off the tubes unless they are hot or warming after all.

SOLD, thank you for your interest.

Hi Gents and possible Ladies?

Have a desire to try reprogramming the firmware on my JBL LSR 4300 speakers. The digital pcb display at a quick glance receiver and A-D-A converter capable of 24/192 PCM, but somehow, and I guess it is in the software controlling the speaker, there are limitations to 24/96 PCM.

Is there anyone here in this huge community of knowhow, who actually know how it all fits together, or even know how to "cure" this on purpose limited performance.

I tried the JBL expert support. They told me this software is JBL intellectual property. I agreed on property, but made my reservations clear for the other statement.

I am electro-engineer for high power distribution networks (MW and TW), so my insights in this micro-world is nothing worth mentioning. Any help is highly appreciated.

Thanks in advance!

Stefan from Sweden

I bought a used turntable off ebay and when I got it there was damage to it. I got refunded almost all of my money with the offer to keep the table for $20.00 so I took the offer thinking I might find a different tone arm for it.

If there somewhere a person can pick up a tonearm at a reasonable price? It there a correct distance from the center of the platter it needs to be installed? I guess a site where I can find all the info I need?

It has a really nice direct drive platter but a cheap tonearm.

I haven't had to buy drivers in a long time. I see a bunch of stuff at Parts Express, and I see Madisound is still around. Speaker City seems out of business and Zalytron shows almost nothing.

I'm looking for a 12" woofer which will bass-ically 😉 run open baffle in a wall with an understairs closet behind. Ideally the woofer would have a top end die-off to cross over to a horn.* No sweet spot listening, more like whole-house sound, an EQ may well gently massage the sound. Not wanting to spend hundreds but the cheapies at Parts Express don't look too damped.

A grille to cover all this is also needed, perforated metal pre-made, I'm not making wooden frames for grill cloth.

*No I haven't decided which. I really want to use the Dayton 10" waveguide just cuz it's so cheap and cool but don't know what driver or tweeter I would mount to that.

I am not a tube guy. So I do not have a high voltage lab supply lying around on the bench. Only a pair with max. 30V 5A. But recently I want to experiment with a solid state amp for electrostatic headphones. So I thought a lab supply capable of +/- 400V 60mA, regulated, and with adjustable current limit would be handy.

To reduce costs, I want to use my low voltage supplies I already have, and use a switcher to convert it to the required high voltage, low current. After quite a bit of searching on the net, the not-so-obvious LT3751 actually fits the requirements best. The standard circuit on the datasheet is supposed to be capable of 500V 170mA. And all the components, including the transformer, is readily available. Apart from my specific application, I thought this might also be rather useful for tube fanatics not willing to compromise on their choice of Car Hi-Fi gear.

The schematics attached are as built successfully. They largely follow those on pages 26 & 34 of the datasheet. The negative version is not listed on the datasheet. It requires reversing the primary of the transformer, as well as the usual polarity changes after the secondary. Because the built-in “regulator” only accepts positive voltage, the output feedback voltage has to be inverted by an additional inverter using a LT1006.

I had quite a bit of trouble getting the converter to start without triggering the voltage limits which then turned the converter off. It could of course be due to the high current draw at start-up, and the current limit of the upstream lab supply. In the end, after a lot of trial and error, I managed to get a stable set up by using a 1k-4.7µF de-bounce at the charge pin. It also helped to lower the supply voltage to 22V. And I also found the inclusion of C6 (10nF) necessary.

To allow a coarse selection of output voltage, the feedback series resistor is split into 8x 49.9k. This, together with a 6-pole rotary switch, gives 6 output voltage steps between 170V and 420V.


Patrick

.

Some data on in this case 3 processors (x-over filters PEQ's All-pass filters and some other craziness).

Processors: “Interim report”: Lake LM26 vs APEX Intelli-X2 vs Linea Research ASC48 | Timo's World all around the globe

I got this Denon DCT-R1 for around $250 in hope I could repair it. It has audio signal out of the RCAs, but not out of the high level output. It has a HA13150A for the "amp" and it appears to me that pin 2 is grounded (or not getting its 3.5+ volts) and is in standby mode.

I have traced Pin 2 as best I can. It goes (from the amp backwards) to a small capacitor (I assume to smooth out voltage ripples) and also through a 000 SMD resistor, which leads to a small SMD device with the marking MB. That device has one leg on a pad that leads to nothing, so I'm assuming its used to secure it, another leg connected through the 000 resistor, and the last leg going out to a few resistors (which have their other side on a ground circuit) and another unknown device with the marking 13(28 sideways).

The 13-28 device has 5V on its one leg, which passes through to the other leg on the same side. The leg on the opposite side is the one that goes through to the resistors and MB smd device. If I jump across it, giving 5 volts to the MB device and resistors, I get audio output.

I have found 3 other 13-28 devices. 2 of them have 5 volts on the same legs and nothing on the opposite leg. 1 of them has 12 volts on the leg that has 5v on the other devices, but that one allows the 12 volts to travel across the device and it does not jump from leg to leg on the same side.

I'm sorry for the poor description, but I don't know what the devices are so I can't number the legs appropriately. I've included a picture that shows the pin 2 travel (red), as well as where ground (black dot) is, and where my 5v is (green).

The cd not ejecting seems to be a belt, so I have one ordered, but I'd really like to get the audio working...even though I will probably use it through the RCAs regardless.

Not mine but I had to share this brilliant rebuild of a pair of Cantons using laminated plywood panels, in an untraditional method. I know how my next pair is going to look....

Pair speakers based Canton Fonum 301 DC | eBay

While I would love a pair of 604, or EV, University or other vintage coax, It's not in the wallet any time soon. Are the Eminence any good? Looking at 12 or 15 inch with threaded center pole for Eminence comp driver? Anyone try them?

Just curious for the hardcore experts here. Besides *size* is there any advantage either sonically or in "theory" that a sealed sysem (infinite baffle) beats a TL in the 100Hz-20Hz range??????

Not looking to start a war either way, just asking for either "scientific" or "subjective" thoughts.......

Thanks!

When I was in college in the 1980's, I built a SWEET sounding amplifier kit by Mark V electronics called the TA-1000. It was supposed to be in class A operation for low level and moved to class B at high power... It was touted as a 100 watt unit into 8 ohms with exceptional noise and distortion performance. I had unlimited access to as many caps as I wanted, so I stuffed in 120,000uF caps on each power supply rail. I brought it to a high-end audio store in the day and sounded as good as ANY high end amp on the demo shelf. I recently pulled it out again and it sounds as good as I remember.

Sorry, but I do not have immediate access to the part values. I can get them, but it will be many months till I get back to the place where I left them. If I recall correctly, the output transistors Q9,10,11 and 12 are 2n3055(?) and MJ2955 (?). Q7 and Q8 are the TIP 41c and TIP 42c.

I dug up a schematic of the unit and wondered what made it sound so good. Perhaps I can get some comments from the group on its design, layout and whether it was anything fancy or just plain-Jane average. Let me know what I have here.

Aragon 8008bb.
amp works fine and I just installed new main psu caps ultra low ESL
I’m trying to get the amp to have more jump , faster transients
The tone is pretty neutral and I am thinking of bypass caps on main psu caps.
But I do see some amps use local driver board caps.
all I see on drover boards is 2 100uf caps
I’m no way am I saying the amp is bad I have had them many years.
my speakers are demanding. nom 4 ohms that goes down to 1.7 in upper Mids
Infinity IRS v are a handful.
anyone have any thoughts please advise I’m willing to try anything.
My main amps are ML 33 amd now I’m buying a krell FPB700 cx too.
I’m working on ML AMPS finishing the last of replacing caps.
So this amp will be back in for a couple of months
I have set bias to 20 mv amd will Listen and increase to max 30 mv
Even if I need a fan lol.
any ideas are very welcome.
The 4004mkii had 4 caps on driver boards per channel.
Advice please and please no bashing of good or bad amp ideals.
Al D

Hello anybody.

Do you have an servicemanual for Rega Exon 3 monoblock amplifier?

I will be very pleased and thanksfull if some off you could help me getting one.

Best regards
Kim

I've been working on a design for my desk that will get down to 35hz, but hopefully still have the great imaging and coherence of full range speakers.
I've done a pretty minimal 1st order crossover with just an inductor and zobel for the low pass, and a single cap with a few resistors for the high pass. The simulated response is less flat than it could be, but I'd rather keep the fewest number of components, especially capacitors, in the signal path as possible. The modeled box response for the Anarchy 7" has an f3 of 35hz in a 25L ported enclosure. I know the bass won't be detailed, but I just miss having it there at all.
I don't think I really understand the phase plots, is there something else I need to be doing for coherence? I think the voice coils will be aligned in the enclosure, but may have to tinker once the drivers arrive.
It seems like the next step is to get the drivers into the cabinets and start measuring. This is my first design after having built a few designs by others, I've done lots of reading, and some things are still over my head so please let me know if I've made any glaring errors.