FS: 5.25" midwoofers Audax HM130Z0, Eton 5-212, Aurum Cantus AC-130F1

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

DCM speaker recommendations for my older Yamaha receiver

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

Serial driven parametric equalizer

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.

Pocket Mic preamp

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

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Dodecahedron driver recommendation?

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? Measurements of CERMECH CS4398 DAC With NJM4580D

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.

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Anarchy 7 - Wavecor MTM Crossover

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.

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FS: Mirand Audio USB DAC V.1 AK4490 DSD direct diy

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

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Using REW for XO with regards to phase

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

Soft Start and Standby Functions for your Aleph Amplifier

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

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Facebook Users

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

Tweeter suggestion for monitor Satori MW16P

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

Lumin U1 Mini Upgrade power supply

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

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Sub Heatsink for 6 Zener Diodes in DO5 Outline for electric isolated Mounting

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.

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Help needed for unknown SEMELAB Power Zeners "8136 8215E"

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.

DIY Line array - Matching AMP power with the RAW speaker

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.

Tian Stability Plot at multiple points across the Output Swing

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:

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Perfecting loudspeaker design using novel polymer materials

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

audison av12

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.

Silent fan replacement in ART SLA-1

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??

BBC style thin wall enclosure - how thin can one go?

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 🙂

impedance question

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

Cheap solid state relays

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.

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Am I doing this right? Tuning gains on mono amp for bass

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).

FS: tribute choke, E182cc quad, Siemens sikorel 10000uf, jupiter vt caps and more

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

Software to design amplifier circuit

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.

Recommend a 6" long throw driver

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?

Low pass cut-off advice for the SB26NBACS45-8

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.

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Shigaclone mk2 black for sale

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

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Leaving voltage on the plate with a cold tube...

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.

JBL LSR4300

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

Tone arm replacement?

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.

So, where can one buy loudspeaker drivers these days?

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.

LT3751 Driven, +/-400V Shunt Regulated Supply

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

.

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Denon DCT-R1 No Audio No CD Eject

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.

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Laminated plywood cabinet Cantons for inspiration

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

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Seeking expert comments on this power amp topology

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.

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Aragon 8008bb cap upgrade

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

FF85wK + Anarchy 7 FAST monitor

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.

e0Oeomb.jpg

PAzxNQI.jpg

Need help checking LM27762 layout

I designed a power supply for headphone amp which take 5v from usb, use lm27313 to generate 5.4V then go to LM27762 to have +/-4.7V. It works at some extends as it generate +/-4.7V well but the LM27762 seem to upset LM27313, it oscillated and can clearly see at noise spectrum at 6k, 12k ... I Change LM27313 to LP5907 4.5V and it also has this problem, disconnect it from LM27762 and use resistor as load it work just fine, so the problem must come from lm27762. I also tried disable negative part of LM27762 and the ringing of pre-reg is also gone so must be the charge-pump inside LM27762 upsets pre-reg some how.
Here is picture of noise spectrum of pre-reg LP5907 4.5V when supply to LM27762:
Wh4o4MK.png

This is layout of the LM27762:
7TbRZSg.png

But it also strange that before i have made another LM27313 + LM27762 as this one but the two is very near each other and it works fine without oscillation
juIvPjx.png

Hope some one can help me check on this 🙁

Oakley headphone submini tube amplifier for headphones

Hi everyone I'm new to the forum, I had a question. About the Oatley sobmini headphone am kit. I have read on this forum that former incarnations of this headphone amp were used quite successfully as pre-amps for hi-fi. I was wanting to know is there anyway this kit could be.modified to be used as a bass guitar pre-amp? If so how exactly what parts would I change and how will it effect the sound ect... Also if I want to wire it up not using battery power can I just get a 3 volt wall wart and use it or do other things need doing? And one last question. Are there any eBay Chinese pre-amp kits that are capable of being used as is or modified for bass guitar pre-amp use?perhaps the 12ax7.and 12au7 type with hv supplies would be the closest thing? IDK noob obviously. ....thanks so much and nice to finally post

Which Dayton Audio 12" Subwoofer (HO-4 or HF-4) in old REL Q100E enclosure?

Hi

I'm going to upgrade my old REL Q100E!

Its been used for movies and will continue to be used for movies.

REL%20Q100.png

Enclosure: 50 litre (1.7 ft.³), sealed box, Dimensions: 400 x 415 x 400mm


I've got a 300W Class D Monacor SAM-300D/Yung SD300-6 plate amp I'm going to install.


I'm wondering whether I should put in a...

Dayton Audio RSS315HF-4 12"
or
Dayton Audio RSS315HO-4 12"

Any advice appreciated, thanks!

Help in repairing a vintage amp

Greetings



I have an old amplifier i would like to restore, but i have problems with pot values. The volume pot, which has a tap for loudness, is ok. Bass and treble pots are however bad and i would like to replace them. They have damaged carbon tracks inside, usually i open them up and clean them but i cant for these two.


Here is the tone control circuit and i would like to ask if this circuit could be modified for different values of potentiometers, by that i mean more standard values, beacuse here in slovenia i find it difficult to obtain even a 220 k lin stereo pot, but i simply cannot find a 22k one.


Any suggestions for modification🙂



s9+D+tja27Mtuaj2nU6d5+14h9Fav4PX20liIKsS5IAAAAASUVORK5CYII=

Second opinions needed on a Luxman L-215 mod.

Hi everyone. I am one of those guys who really wanted to lean electronics properly but never managed to get by the basics in school. I therefor need a second opinion about some alternations I have made to a Luxman L-215.

I really like the look and the sound of this little amplifier but the one I managed to pick up had the same problem with overheated zener diode as many other have had. Just take a look at the attached images of the heated area around the original zener D112 (HZ20-3) and the back of the board. I also attached a part of the Luxman L-215 schematic (purple = 24V pilot lamp, yellow = zener diode D112, red = resistor R153 and green = capacitor C133)

I followed the advice at this page and replaced the blown 24V pilot lamp with a LED but there are a couple of things I am not 100% certain about.

I measured 23.9V, 112.4 mA before removing the zener and original resistor R153 (300-3) and 44.3V, 15.6 mA when the zener was removed and the resistor R153 (300Ω 3W) was replaced by a 2.7kΩ 2W resistor. That was before inserting the LED (rated 2V 16mA) so I guess there is about 42V over the capacitor C133 (47µF 35V). The guide I was following state:

“When the light bulbs are replaced by leds (that I prefer), the zenerdiode D112 is obsolete and can be removed, the 300 Ohm resistor R153, must be replaced by a 1,5 to 5,6 KOhm 2W type as on the photo, depending on the type leds you use, and then you have the correct power design.”

The zener D112 is gone and the resistor R153 replace by a 2.7kΩ 2W resistor but the text does not mention the capacitor C133 rated at 35V. My guess is that it mainly serve as a stabilizer for the pilot lamp and that it is not really needed for the LED (but this is me guessing). So I desoldered it and the amplifier seems to work perfect without it and the LED also seems unaffected by the removal of the capacitor C133, but I really don't know if its good or bad to keep it or remove it from the circuit.

So this is really my question, should I put the capacitor back in and what about the 42V in that case? Or should I keep it removed and not worry about it? Or should I do something different like add a new zener diode but I guess I then have to replace the 2.7kΩ 2W resistor and put another resistor in series with the LED…

Any second opinions are welcome.

Thanks in advance / Rob

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Driver distortion curve shape

I al looking to understand the physics of why the distortion curve for drivers, any driver so ignore this example, has the same basic shape of the sharp knee. The only exceptions is a couple of tweeters I have measured. It does not seem related to x-max, impedance, loading or anything I can think of. The only papers I find on driver distortion focus on the shape of the field in the gap, underhung coils, suspensions etc.

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FT/FS: 1943 WWII Tubes kit new old stock

Hi everyone

I want to trade or sell my amp & radio us navy kit never used come from us destroyer Ship in Normandie, France 1943
For Panasonic RS-296US cassette deck working or not but complet
For sell best offer
I have all original box
Best regards

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2 way crossover / alsa / ecasound / mono speaker

Hy

It most likely has been discussed before but I probably used the wrong search term so I didn't find exactly what I was looking for.
I hope you don't mind if someone can help me to determine what I need to search for.

So I got an Pi with an two channel amp connected over i2c.
On CH0 there is the tweeter connected and on the CH1 a woofer.

Now whats the best way to:
  1. mix the Stereo sound to mono
  2. run a hipass Filter on this mono stream
  3. play this filtered mono stream only on CH0
  4. run a lowpass filter on the stereo mixed down to mono stream
  5. run this on the CH1 port

And maybe do some db adjustments on each channel.

I read some threads where you could achieve this with ecasound or alsa.
Currently the audio is played by a snapclient so alsa would probably be better but can alsa handle all the above points?


Any help is greatly appreciated
thx
Andy

Profire 2626 good latenzy-wise?

I can buy maudio profire 2626 very cheap. Im considering to put triggermics on my drumset and fill it with pillows, so i can play without disturbing my neighbors. I will listen through headphones via some synthesizer on my pc. I never tried this but I recon latenzy needs to be very low. I dont know much about soundcards so I would like to know if you could advise me if profire is suited. It has firewire.

Cheers!

Wide Band Speaker Crossover

Hi, i am new to designing a crossover. I currently have a TangBand W3 Wideband Speaker, Scanspeak D2904/60000 Silk Dome Tweeter, and a Hustler Audio Neo HT30 (I think it is similar to Fountek JP3) Ribbon Tweeter. I have designed 3 versions of the coilover via experimenting on XSim. Can someone help me to figure out which design is the best? Or maybe someone want to redesign my crossover? Any help is appreciated. Thanks!

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