suppose interstate define 2 : 3.5 current of Primary is about 35ma voltage of 200 (7VA)

Can I use main transformer that I have on hands which primary of 220V and secondary of 380V - 0 - 380 200mA?

it is almost the same ratio 220V primary : 385V secondary (close to 380V).

Does anyone know anything about this woofer. It is double spider Numbers on it are 117V and 050324.

Is there anything other than basic best practices to consider when making power cables? Just want to make sure I don't start a fire due to overlooking something. Thanks.


Here are the steps I took (no fire yet lol):


I used 2 X 18 awg stranded hookup wire for each conductor.
Twisted and braided.
Two wraps of PTFE tape.
A wrap of foil tape.
Braided shield.
Two wraps of PTFE tape.
Braided outer sleeve.
The braided shield is grounded at wall receptacle end.
I used Marinco connectors on both ends.

I’ve wanted to do a Line stage preamp for a long time that would allow one to use various tubes of similar operation, with a topology that would be suitable for any tube inserted, provided they had the same tube base. So I came up with this idea after a line stage protoboard I built. The 9-pin tubes have a heater switch that will allow for series or parallel operation from the same supply. The load resistors to the second triode can be adjusted for any particular load line.

The tubes shown in pic are a pair of 6N6P tubes, that I prototyped. A very nice sounding tube.

Hi Gents,
I know it is not the correct way to do things, but can anyone give me a method to enter an approximate value in the tweeter delay field of x sim if the tweeter actually measures 1/2inch forward of the woofer on the baffle. I am measuring from the top of the tweeter dome to the top of the domed woofer dust cap.
I realize that this is not as accurate as the "interferece" method, but hope that there is a general rule of thumb which can be used for someone who is able to use some of the features of X Sim but has not been able to understand and apply any of the more sophisticated ways of determining delay.
I have designed two different 7L two way speakers which both sound quite good and measure plus or minus 3 db from 1K to 12K using a .5 inch setting in the tweeter delay field, but maybe I've just been a little lucky. Gentle, constructive input would be greatly appreciated, I am but a beginner after all.

Best,
Jay

I am experimenting, from as design point of view, not sure if I will actually try to build it, with the idea of a Para-UL, Parafeed configuration for a 12L6 power tube with a Bogen OT. I have lots of these inexpensive OTs and was thinking I might be able to boost the performance of the 12L6 family of tubes using this OT.

This is more of a MidFi experiment so don't rain on my parade, the object is to improve the specs if I can. This is in line with typical mass produced radios and portable turntables used in the day. The Bogen T72510 is actually much better than the cheap OTs they used back then.

I'm looking at about 3W 50-20K. THD TBD, running the 12L6 at 188V with a 5k:8 Ohm OT tap. (How realistic that is, is questionable, but that is the specs from Bogen and the 12L6).

T72510:
https://www.bogen.com/products/pdfs/specialelectronicspdfs/WMT1As.pdf

12L6:
https://frank.pocnet.net/sheets/093/2/25L6GT.pdf

Anyways, I appreciate any comments on this design. The values I have are my first shot attempt so I expect they need some tweaking. My theory is not all that solid and I have very little experience with MOSFETs, but for you all I bet this is a fairly simple circuit mod.

I was cooking tonight and my options for music were either a Lenovo Smart Display on my counter, or the Alpair 11ms Nostromo's in my living room 20ft away (via my dining room, which connects the two as the bottom of the U). I've been researching multi-sub options for the Nostromo's (like the bucket sub), when I had an idea.

Chromecast (which I have throughout my house) supports groups of speakers. Speakers can be in multiple groups, and each can have delay within the group.

I'm thinking of building and placing a few subs in the dining and living rooms, powered by a single amp, sourced by a chromecast with an LPF. This chromecast would be a shared member of both the 'kitchen' group, and the 'living room' group, filling out the bottom end of each.

Other than the obvious gap in lower migrange left between the smart display and the subs, I think it might nicely round out the sound of both rooms.

Has anyone tried something like this, or have any ideas or criticism?

Hey Guys,

I'm looking at building a few PA systems. I have a friend that's a cabinet maker with CNC machines ect and I have access to drivers/horns/Powersoft amp modules ect.

I was just wandering if anyone has any really good designs that they can share.

Ultimately, I'd love a 15" coaxial FOH speaker box on top of a 18" sub for small weddings gigs. but open to building anything.

Thanks!

I have made a little portable music system and powered it up with four Lithium battery by making a 2S battery pack. It should give 8.4v when fully charged. Everything is fine but I found it very difficult to charge this pack fully. I like to make a charging system with full charge indication led. Can anyone help?

My Yamaha RX-V3000 AV receiver (around 2001) does not keep the settings in the memory and it is a pain to reenter them whenever the power goes off. I found that there is a memory backup capacitor "super capacitor" (C662) which is 0.047 F 5.5V (see photos). I located this component but it is on a circuit board that looks like it would be a major production to remove and I fear that I could cause damage trying to get that board out so that I could desolder it from underneath and then install a replacement. Could someone kindly answer the following:

1. Other than not being aesthetically pleasing, would it be OK if I removed the memory capacitor by snipping the solder tabs on the top side of the board that is more accessible, and then solder the leads of the replacement part to the remainder of the tabs that go through the board? (Or I could attach the replacement part with short jumper wires to these tabs if necessary?)

2. I am not familiar with this type of capacitor and to me it looks like 2 coin cell batteries back to back. It is my understanding that this capacitor slowly discharges and can retain the memory for a few days and then gets recharged when the power is back on (and thus it is not actually a battery at all.) Is there any possibility that when replacing this memory capacitor that damage could be done to the memory chips and are there any precautions that should be taken. I am assuming that I would receive the replacement capacitor in the discharged state, but should I discharge it by shorting its 2 leads to be on the safe side?

I want to be extra careful because I do not want to kill this receiver. For a short term solution I have the receiver plugged into an uninterruptible power supply that helps keep the settings during short losses of power, but the UPS battery seems to get depleted in a matter of hours and sometimes I like to unplug the unit for longer than that during times of thunderstorms. Also the UPS probably adds noise since it is not a clean sine wave. Thanks in advance for any advice.

Any suggestions on what to do a pair of energy pro 22 speakers. Rubber surrounds compromised, tweeters likely dried out. Should I turf or replace with new drivers.
Thanks

Dear all,

I am working in a project to convert the acoustic energy aegis three speakers into 3 way active dsp speakers.
https://www.listeninn.com/products/Acoustic-Energy-Aegis-3-1343-B.jpg

I opened the midwoofer just to check the interior and I saw a piece of hardware connected to the tweeter, with nothing written on it.

Of course, one of the critical part of the project is having the tweeter protection cap in place. I wonder if this piece of hardware is actually a tweeter protection cap, so i don't need to calculate and buy a capacitor.

• ¿Do you think i could stay safe with that "capacitor"?

Just for your information,
I attach a close measurement from tweeter, mid woofer, woofer and woofer vent.
I see much overlap between the woofer and the mid-woofer, and I pretend to increase the signal into the woofer in order to extend to lower hz and made some equalisation for response correction.
I already made some tests with standard biamp capabilities of the speaker (still with the passive XO in place)

Thank you all for the advise

Hello all, selling my excellent DAC that has been the cornerstone of my system for about 5 years. A couple of superficial scratches on the powdercoated top, see pictures.

Dual mono and Differential design; even the usb interface has it's own dedicated power supply. Accepts USB up to 24/192 PCM, optical 24/96. Really really nice output stage and dead quiet on even the most sensitive horn systems.

This one has the Lundahl LL1527XL line transformers to convert the native differential output to single ended.

Please note the USB is compatible with Windows and Linux systems; it is not compatible with the current Mac OS! You have to roll back your system to Mac OS 10.7 (i think) for a compatible driver. Or you can swap out the otherwise really nice hiface usb interface for something else.

$1200 OR BEST OFFER+ shipping to USA. I am willing to sell to europe but shipping will be at the cost of the buyer.

Hey everybody!

I have built a couple of guitar amps in the past, but the SSE is my first foray into HiFi amp building.

I started the build back in March. When I ordered the transformers from Edcor, I had them shipped to Sumas WA, just across the border from me (I'm a Canuck). Unfortunately, they arrived a few days after COVID shut down the border... The project went on the shelf as I not-so-patiently waited for the border to reopen. And waited...

Eventually, I gave up and managed to find a cross-border shipping company/broker to bring the transformers across the border.

Finally, I was able to throw it all together for a test run (a proper enclosure will follow). There were no issues that I noticed upon initial power-up, and the amp sounds great! I am currently running the amp in triode mode with no feedback.

However, I did notice that my power tube screen grids are glowing (EH 6CA7EH). Not an even glow across the whole grid, but only on a few of the grid filaments. Is this possibly a sign of faulty tubes, or due to the fact that the tubes are running quite close to their max dissipation? I don't see any signs of red-plating.

Vk=38V Rk=560ohm Ik=67.9mA Vak=377V (Total dissipation=25.6W)

The 100ohm grid resistor is dropping 0.95V for 9.5mA grid current, which works out to 3.57W of grid dissipation (which is safely below the 8W rated for this tube).

Specs:
Edcor XPWR002 720V Power Transformer
Edcor CXSE25-8-5K Output Transformers
Edcor CXC100-5H-200mA Choke
90uF polypropylene aux capacitor
Sovtek 5AR4
EH 12AT7EH
EH 6CA7EH

Hi all. After many months of learning about DIY from the nice folks here, I ordered one Amiga MT tower kit and used it as a template for the 2nd matching speaker. I've got a small woodshop that allows me to do that w/o a real issue; it was just a matter of learning the process.

Personal opinion on the Amiga MT: clean and clear, great for music when paired with a sub. I really like them - alot. Serious thanks to Paul Carmody for his work in the DIY community.

Comparison to my B&W 684 S1's: the Amiga's blow them out of the water for clarity, and that doesn't even cover the reduction in harshness. I examined the crossovers in the 684s and no wonder... there's just no serious attention given to them (imo). I dunno, I'm sure they sound like they want them to sound.

Next: My goal is to complete 4 more builds before I order measurement equipment and begin to design my own. I've planned the following:

• C-notes (being shipped now, for my son's 16th b-day)
• Paul Carmody's Sunflower Center (to match the Amigas)
• Dayton Ultimax 12" Sub
• TBD Bookshelf

So, what bookshelf would the community recommend I build to take DIY to the next level?
What speaker would open up the soundstage more and make things three dimensional while working really well with a sub? I considered the X-LS Encore's. Anything else?

Thanks - looking forward to being around here for a long time.

Hi,

I am designing my first sub. I was thinking of making it a cube in shape but elongated box would be ok too. I am using WinISD for the design work.

The woofer is Scan-Speak 26W/8867T00. It is rated for 80W RMS and 200W max. Linear excursion is 9mm and max mechanical excursion is 14mm. On its datasheet the recommendations are V=70litres, fb=25Hz, f(-3dB)=28Hz. I put the recommended volume and tuning frequency into WinISD and changed input power to see what I would get from the plots.

The transfer function magnitude had
0dB at 97.71Hz
-3dB at 27.84

I looked at cone excursion.
At 200W:
*Max mechanical excursion is 14.834mm at 36.91Hz
At 80W:
*Max mechanical excursion is 9.353mm at 36.91Hz
Something doesn't seem right to me. I need to lower the volume to 56litres to not have the driver excursion go over the ratings. Are Scan-Speak recommendations off?

I looked at port velocity.
At 200W:
*23.494m/s at 21.66Hz
At 80W:
*14.812m/s at 21.77Hz
Is that velocity too much? I chose 1 circular port with a diameter of 10.2cm. The vent length is 48.42cm, which is longer than my external cube dimensions. Would there be a problem if the tube has a bend in it? Does the bend angle and arc length make a difference? I had a look at making the port diameter smaller to make the tube length shorter but the velocity jumps up to 36.353m/s at 200W and 22.92m/s at 80W. Is that too high?

The plate amp I was thinking of using is either Hypex FA252 which can do 150W RMS @ 8Ohm or 300W RMS @ 8Ohm. Would it be better to run the plate amp at 150W or 300W? I don't want to blow the woofer, and those excursion numbers look too high even at 80W.

Would someone be able to assist in the design to make sure that I don't damage the woofer?

Thanks

Copper magnet wire appears to be more readily available in required quantities as opposed to PVC insulated wire (without buying in bulk minimum quantities) and is already used in step up transformers.

Would magnet wire be suitable to make stretched wire stators from ?

Would there be any drawbacks (cracked insulation from stretching, arcing, vibration buzz, etc.) ?

As for calculating the open/closed area, more of the "closed" area would be copper versus insulation. The same AWG/gauge wire would have a smaller OD providing more physically open area restricting less air flow.

Any thoughts ?

TIA

Hi everyone ,

looking for 2 pair of those , send me your offer 😉

Regards

Fabrice

How much information is lost when music files are being compressed?


Here are (3) short 10sec samples - in WAV (1411kbps, CD quality), in 320kbps and in 185kbps.

I converted all samples to mp4 files (320kbps) so I could directly attached them for quick listening.

I did attached the master files as zip for more detailed comparison.



You can take a listen and judge for yourself...

-

Hey,
i recently got myself a pair of Dayton Nd105-4 drivers, and now im trying to measure the impedance curve with a crude self-build circuit and REW/Arta.



The cable with the yellow connector is connected to the output of my behringer u-controll UAC222, the red rca is connected to the right input and used as the refference, the silver one is used as the main probe.


I tested the Nd105-4 with Arta and Limp, and from both programms i got pretty similar results, but they got some differences compared to the datasheet provided by Dayton.



This above is the impedance i measured.



And this is how the impedance curve should look like.



This above are both curves overlayed, the yellow one is from Dayton, and the red one is from my own measurements.

My main problem is that the phase curve is nowhere near the datasheet. Besides that, the impedance rises as the frequency goes down. Above 3khz there is exact the opposide problem, the impedance does not rise as mentioned in the datasheet.

I dont know what is going on with my measurement, and already tried some things, for example to switch the rca cables (the reference and the main probe).
I tested both speakers and both times got the same problems

Thank you in advance for any help.

Looking for a simple and good circuit design for an opamp preamp to go with my ACA that uses the dual "Burson Audio V5i Hybrid Opamp" that just became available on the site. It will need to use the same 24V single rail power supply as the ACA. Volume control not needed as I have that already with my source. Any suggestions? A project with available bare boards would be ideal, but not required. Thanks!
And... a simple and good design for a preamp using the same opamp with a differential/balanced input and the usual V+/V- supply. Thanks x2!
I've ordered the opamps already, cause, why not, and also got a number of ne5532's from digikey as guinea pigs.

I have no idea where else to post this so...

Do any of you guys happen to have a copy of IEC 60268-21? I need to understand the portion on max SPL testing (I believe this is Chapter 16.2) but I can't swing the $350 to purchase it. If someone can help me out, it would be appreciated. Feel free to email me directly at hardisj at gmail dot com.

Thanks,
Erin

Hi,

At the moment, I use a Windows 10 PC to perform room correction using Equalizer APO. It applies an FIR filter (generated with DRCDesigner) to all audio on the computer, including an SPDIF input coming from the TV (I simply configure Windows to "listen" to the SPDIF as if it were a microphone). Audio is then sent to a DAC with SPDIF. This works very nicely, as anything hooked up to the TV gets corrected and sounds great.

I'd like to remove the PC from the equation as it feels massively overkill for what is essentially a DSP unit sitting between TV and DAC. I ordered a Raspberry Pi 3 B+ and the Hifiberry Digi+ I/O (this has SPDIF in and out) as I figured there must be a way to do the same but on a smaller, linux-based scale.

However, I don't really know what I'm doing with it! Some software recommendations would be great. I need some way to play any audio received through the digital input, apply an FIR filter, and send to the digital output.

Any help would be greatly appreciated!

Hi, i'm Facundo from Argentina.
I'm trying to make a small guitar head using a tpa3118 sanwu module, using a simple circuit as a preamp.

I've already tested the module with other sources of sound like differents guitar stompboxes or floor multieffects (like line 6 hd500, fractal ax8, axe fx rack unit, etc). All theese units worked flawless

But when i use an analog preamp, like a fetzervalve from runoffgroove if i hit hard the strings of my guitar, the class d module gets into protection (it makes a hard and loud "click" per second)
http://www.runoffgroove.com/fetzervalve.html

i'm thinking that may be there is a problem with the input signal of the class d module. So, i've removed one SMD resistor, to let the input gain in 20db. It worked a little bit better, but still have the "protection" issue.

i'm using the same power source, a notebook charger, 24v 4A for the preamp and class d module.

What i am doing bad?

The preamp sounds gorgeous, i love it, but i cant trust on it if i have to "play softly"

hello guys ... i have a problem on my marantz pm50. Turned back on after some time ... I connect two 6ohm speakers ... but I hear some bangs / noises coming from the speakers. I turn off turning on same story again after a while. At some point absolute silence. The amplifier now turns on but the protection relays on the speakers (normally open I think) do not close (no click) and the amplifier obviously remains silent. No audio ending in short (measured dual +/- 50v on all 4). No sign of burns. Where would it make more sense to start from? from the annoying integrated skt3062 or from the relays themselves? I believe that the relays do not close because they see something upstream before it malfunctions and therefore remain open. After being completely dumbfounded, he also left for a few seconds but only after a long time on. Can those relays have a timing circuit that is moving on to a better life? I would like to put it back together in an aesthetic condition, as if new. someone help me or have the wiring diagram. Thanks in advance greetings Mino

I will be building a My_Ref Fremen edtion LM3886 later when the new boards come in from the current group buy. I will also need a linestage, which I want to DIY, and wondered if something like this will match up decently:

DIY kit 2SK246/J103 FET input PER AMP board Imitation JC 2 Preamplifier Class A Dual differential|jc-2 preamplifier|class a preamplifierclass preamplifier - AliExpress

I thought about a passive but am not sure if that is the way to go, I have read about bass degradation with them but no experience. It would be the simplest to build. I was a licensed repair tech back in the day and can pretty much build anything from a schematic.

I have a Shiit Loki so I don't need tone controls, just 3 inputs, volume control and output.

Any suggestions?

I am trying to repair my Linsley Hood designed Class A symetrically driven headphone amp section of my pre-amp that I use as a high level output to my Power amp.
I am guessing that the output transistors are faulty(after over 10 years of use) so have removed them.These are the TIP 41C and TIP 42C(higher rated than the original design which shows TIP 41B and TIP 42B). My Question is,is it important for these output devices to be matched to have close hfe values,particularly as they get quite warm and I assume they would last longer if they shared the output current evenly.If this is important where can I get matched pairs from?
Alternatively I have a lot of quite closely matched(eg-197 hfe PNP/170 hfe NPN) MJE 15034 and MJE 15035 transistors) to hand which have similar specs to the TIP 41C and TIP 42C but slightly lower maximum current and Power ratings(4 Amps,350V,50 Watts as opposed to 6 Amps,100V, 65 Watts) according to the data sheets.Would these be a better alternative?
I have attached the schematic that came with the kit for reference.
Any advice much appreciated.

My Infinite Line Source project

Brief history - I have built a line array (LA) with the same drivers in the past - Halair Column - my line array build (20 FR drivers)

My main goals this time is to improve sound quality, by increasing numbers of drivers from 20 to 24 and making a "extreme" cabinet 🙂
The outside will be conventional with a rectangular box but the driver volume will be elliptical and the "unused" volume will be filled with "epoxy granite - EG" which is simply epoxy and sand in this case.

EG is often used for machine bases (CNC) as they are easy to cast, are dimensionally stable and also act as a mass damping device. Both attributes come in handy for my intended application.
Speaker weight is estimated to about 80+kg/side.

With 24 drivers per speaker I will group them into two lines of 12 speakers each => I need 2 amps per side. My current LA is connected to a 5x125W amp
but utilize only two of them => I have 3 channels that are unused.

With a 20% cone area increase and 2x available power I expect improved system capacity + a much improved cabinet should help even further on sound quality 😛
Fullrange LA require EQ which I dont have solids plan for yet, but it wont be my old analogue EQ I currently use.

Updates:

• Link - Front baffle design finalized
• Link - CNC'ing the front baffles
• Link - Cabinets constructed and standing, awaiting to be filled with sand mixed with epoxy
• Link - Casting process has begun, 50kg per cabinet will be used
• Link - First line is playing
• Link - December 9th, second cabinet is playing.
• Both speakers are operational, currently tweaking the EQ/DSP to optimize it 🙂

Hello everyone,

I recently bought this music box from amazon for 40€ to test it and amazingly I was very impressed by its sound quality. I wanted to take a look inside and what IC's it uses and I was wondering how they fit inside such a small pcb a DSP. But when I opened it, I saw no signal processors at all. I found some IC's but about one IC I could not find anything on the internet even tho it has a brand and serial number on it.

About the music box:

Brand: ENACFIRE
Model: SoundBar

Found IC's:
[Blue Sky
TK0577E
BJ45]

[AS19AP1Y221-5C4]

[2SES
01NG
024003]

Some pictures:






I couldn't find anything about the Blue Sky IC.

Only something about the TK series:

Could anyone help me finding the Blue Sky Datasheet or similar amp ic's ?
And how is it possible to achieve such clean sound without any DSP ?

Thanks in advance
sG

I am trying to choose the right midrange driver for my project. The driver will have to be capable of at least 110db/1m peaks Without audible distortion or compression. The passband will be around 300Hz to 2500Hz with up to 6th order filters.

For example the SB12MNRX2 will in theory be able to do this driven with around 100w, and crossed the 300 Hz the excursion shouldn't be an issue. Max Power handling is 100w, so that should also be okay.

Can I be confident that this driver will do the trick, or is it something else I should consider?

Hello I want to buy a pair of Sowter transformers to use as I/V I need Sowter 8347, 1465, 9545 , feel free to contact me with offers.

So on a preamp when you mount the pot to the faceplate, whichs how it is most of the time, the chassis has to become a ground plane inevitably because the casing of the pot has to be grounded also.

My question is would it be better to somehow isolate the pot from the chassis (i can think of several examples) so that the chassis can be an earth shield instead?

2nd question regarding the pot's casing being grounded- for a true mono mono psu how would this be configured if i want the ground between L and R completely separate? The pot's casing is usually one piece.

Looked fo this one and can't find it.



So, looking a the circuit diagrams of a few CD players I've found some, have differing sized filter caps after the rectifier diodes and before the regulators in the +/- supplies.


Can anyone shed any light on this, i.e. why a manufacturer would use two different sizes?


My guess is this is mostly because of rail loading but also to keep costs down.


Attached are the PSUs from two cd players that are very similar:
The DCD620 has one 2200µF cap on each rail.
The DCD820 has the same 2200µF cap on the negative rail but a 3300µF on the positive rail. The DCD820 has four additional +5v IC's one for volume control and three for de-glitch (sample and hold)

Wasn't sure where to post this but here goes. I'm trying to use an SMPS made for tube applications. Specs-
(Input voltage: 12VDC
Output high voltage: 150V-420VDC, 1.25V-12V DC filament voltage regulator is adjustable. (Chip voltage regulation, there is a little pressure drop.)
When I connect to preamp,(load), it drops to ~170VDC after being set to output 240VDC. The low voltage 6.3VDC is fine. Attached is pictures of setup:
I'm using an 12VDC/800mA wall wart for SMPS input. Have never used an SMPS before so hoping for an idea as to why?

So on a preamp when you mount the pot to the faceplate, whichs how it is most of the time, the chassis has to become a ground plane inevitably because the casing of the pot has to be grounded also.

My question is would it be better to somehow isolate the pot from the chassis (i can think of several examples) so that the chassis can be an earth shield instead?

2nd question regarding the pot's casing being grounded- for a true mono mono psu how would this be configured if i want the ground between L and R completely separate? The pot's casing is usually one piece.

Can’t seem to figure out why both 12 volt regulators are not working on only getting 0.4 volts on the output leg . Black probe on middle leg .


If you need more pics I can take some .

Any ideas ?

hi all,

i have the this amplifier, it is protection. I tested all the psu fets and output fets, all test good. when i remove the driver board the amp comes out of protection. I replaced the driver transistors (Q5, Q6, Q9, Q12) but it is still in protection. It also comes out of protection when i remove the inductor.

driver board

I had spare parts to stuff a pair of F5 boards and I am not going to move forward with building the amp. The only thing not included with the boards are LEDS and JFETS. I will also include the IRFP9240 and IRFP240 MOSFETS (not matched, but not needed). These boards are UNTESTED.

Asking $80 SHIPPED Conus Only.

I am selling great speakers. Suitable for tube amps (94dB efficiency).

Making top quality !!

High quality material on the crossover - Z-Silver capacitors, silver plated wire for internal wiring ...

Practically unused - max 100 hours.

Price 1.500€

Hi
I've just built a valve preamp from a kit I got on Ebay. When I turn it on, I checked the output from the preamp and over a few seconds I see a high AC voltage of 140v which then quickly goes to zero as the amp warms up. After that it all operates fine according to tests I've done using an oscilloscope at around 2v. I am just somewhat concerned about the sudden high voltage appearing on the outputs to power amp as I switch it on. Is this normal?

I've wired all the grounds to 3 on the diagram.

Thanks very much in advance for your help

Phill

Hello again, I have this kicker zx1500.1 the problem I have is that I get a sound in the output similar to a tone of 900hz piiiiiiiii and it mixes with the audio that I introduce, the audio sounds good but that sound is mixed if I remove it the knob card still persists only when I remove the drive card nothing sounds anymore I have good voltages +90 -90 -12 +12 +5 does anyone have any idea what it will be?

Hi all,
Apologies if this is better suited for the Software Tools forum, but it's specific to vacuum tubes.

Can anyone provide or point me to an example of how to set up a circuit in LTSpice to generate the composite curves for two tubes in push-pull? I can generate the curves just fine for SE circuits, but I just can't figure out how to do it for PP circuits.

I've looked around for examples, and the only one I could find was by posted 15 years ago by John Podesta. Unfortunately, his example is for command-line Spice 3, so there's no schematic. I've tried reading his netlist, but I'm having a hard time identifying some of the components and how they are connected to each other.

Hi
After messing around with 12 and 24v boards, l'd like to step up and try some higher voltage boards. Have power hungry speakers that could take it and more.
I see tas 5630 and tda7498 mentioned a lot, but these seem to be a bit long in the tooth by 2020.
Is there a newer better alternative around, still in the cheap camp? No hypex budget, but would like something a bit reliable.
Thanks for your time.

Does anyone know what the smaller IC in this picture is?

Hello Everyone,

I just bought a 100m reel of RG-59 cables marked as "mini" (⌀4mm), that I was going to use for CCTV. Unfortunately the external diameter is smaller than what my BNC plugs could accept (⌀5.35mm).

What would be the best solution:
1. Buying some BNC crimp connectors for ⌀4mm coax and use the RG-59 for the video?
2. Buying a larger diameter coax for the BNC crimp connectors and keep the RG-59 for a later project: the audio signal from the cameras? Is the RG-59 good for this type of audio application?

Many thanks in advance.

First post so please be gentle 😀 and apologies as it is a little long. Please bare with me.

Been into Hifi for a while working through a number of systems -

1980's Sevenoaks pick n mix - Rotel CD, Sansui amp, Mission 737
Proper System (sold 🙁) - Technics 777 CD, Quad 44/405-2, Kef 104/2 (AKA the Wardrobes by Significant Other)
Current AV - Denon BT2500, 3808, B&W FPM6/4/M1
Current Office - PC, Fostex A3 Dac, 2x Rotel RB850 (bridged), B&W CDM1SE

Also have built a Kit car and restored classics so am reasonably OK with tools etc.

Anyway, looking for a future project and have had a few ideas that I would like to see if I am completely barking mad or not - All comments gratefully received.

Idea -
Looking to build some floor standing monitor speakers i.e. flat response. I always liked the Kef 104 mid range and the sound of both my CDM1SE and my Son's Yamaha H7's, which are pretty neutral and really show off good recordings and show up bad ones.

Doing a bit of lateral thinking and too many hours on the web I thing the following setup maybe / possibly work at a sensible cost (approx £500 per pair)

Drivers -
Monacor DT-107 1" soft dome tweeter (80W)
Monacor SPH-145HQ 5.5" Mid (50W)
Monacor SPH-8M 8" Woofer (100W)

If you get the frequency/dB plots off the Moncore website and overlay them it looks like they all have a pretty flat response and with cross overs at approx 300hz and 3Khz the composite curve looks pretty good (I know this does not take into account enclose effects and is rough and ready but a start). I can also get the drivers for less than £150 per speaker.

In order to keep the inherent flat response I am looking at a sealed box design for the mid and woofer and reducing any internal reflections or box flexure. Using the Monacor data and the MH-audio closed box calculator for a total Q of 0.65, the Mid volume should be about 7.5l and the woofer about 29l. Comments on these volumes please and use of total Q = 0.65.

I have looked at various speaker designs and like the organic shapes and reading about the nautilus shell / helix / spiral speaker performance I think this is what I will be looking into.

For the Woofer I am assuming the box shape is less important so will be something like a water melon shape i.e. no sharp edges and for the mid a nautilus shell logarithmic spiral shape. I can do designs on CAD and scale to get the internal volumes correct (see above). The tweeter only needs a cavity to put it in, no volume, correct?.

There are many ways of manufacturing this but I will be looking to mould the shapes into a fibreglass half shell (think jelly mould) using the CAD model to provide profiles that are stacked up in wood to make the melon/shell shapes. The fibreglass shell will be backed filled with flexible polyurethane foam to provide some rigidity and also damping (self expanding, similar to memory foam matresses without the memory), these will then be bonded together and encased in a more traditional looking 1" MDF enclosure, leaving space at the bottom to mount some active components.

I also like the idea of a quasi active set up so as I already have the rotel power amps I am looking to do the following -

1x RB850 running in stereo for the Tweeter and Mid (could expand to two bridged in future)
1x RB bridged running the Woofer
(need to get 2 more Rotel Amps). RB850 is rated at stereo 50w RMS into 8 Ohms, or bridged 150w RMS into 8 Ohms.

Both amps will be fed by a 3 way mono active crossover like the Behringer CX2310 (£70) so I can set the individual driver gain and low/high cross over points.

You still with me?

In summary - Semi active, floor standing full range (ish) monitor speaker -
Behringer CX2310 active crossover (x2, one per speaker)
Rotel RB power amps - initially 2 per speaker, 1 stereo for Tweeter/Mid and 1 bridged for Woofer
Sealed box design per driver - Woofer in elipsoid shape and Mid in Log Spiral shape made from fibreglass shell, back filled by flexible damping foam and in 1" MDF enclosure.

So, as already said, am I mad, is this feasible, does it have a chance of providing what I am after and thoughts on the Monacor drivers (don't seem to be used in UK much) or potential other alternatives for similar price (Dayton Audio RS Paper range ?).

Thanks.

Hi folks,
I'm brand new here, so I may ask you to be gentle...

I've owned a much-loved DH-200 for 35 years, powering a pair of DQ-10's and was not the original owner. So I was not the person that built her. The past few years she's been getting very warm on the right channel, but still sounding fine. I'm of course concerned that something is wrong after all these years. Reading through the posts on the forum here I feel I'm far beyond the knowledge to really dig in to the details of where to begin, though. I don't want to damage the amp, but I do think it needs help.
My question is, where do I start? I want to leave it a stock DH-200, so is there a kit or good source that discusses the process of fixing my unit?
I'm an engineer, so I know which end of a soldering iron is hot, but getting too much into the details of the amp may lose me fast unfortunately. Replacing parts, easy. Care to hold my hand and help a guy out? 😀

Thanks!
Ed

Hello there,
Has anyone heard of or tried this phono kit from AM Audio?
it's a good price by the looks of it but wondering if others have listened to it, built it etc. does anyone have a schematic for it?

RIAA – JFET Phono Preamplifier Kit – AM audio

Thanks a bunch,
J

Hi,

My raw voltage is 640 VDC, from a 440 Volt secondary with a bridge (8 x HER308 (1000V, 3 A), and a 1000 uF capacitor into a MOSFET follower (with 40 VDC drop) giving 600 VDC for my final tubes.

On this 600 VDC I measure approx. 375 mV RMS, measured using a 2 uF capacitor and a 100 kOhm resistor in series. The AC voltage is measured across the resistor. I take this measurement with a 600 VDC @ 120 mA load (72 Watt). I also take measurements across the same 100kOhm resistor with a spectrum analyser, using a Steinberg UR242 USB adapter.

As I am looking into some hum issues I need some common sense advice whether this is a good value or not. As you can see the spectrum is filled with lots of even harmonics (100 - 200 - 300 Hz., etc.).

I tried extra filtering (capacitance) on several positions in, before and after the MOSFET follower, but nothing seems to improve the spectral image.

What do you think is happening?

Regards, Gerrit

Clearing out some stuff that's been on the shelf for a while and I'm not likely to use.
Doing this cheap so I'm not getting into a detailed inventory or any sales pitching, I'd just like to see them get to someone that can get some use out of them.

$45.00 via paypal, shipped in a USPS Medium Flat Rate Box which is CONUS only.

I built the Mullard 2 valve preamp but whenever the power amp is on and I
try to this connect the audio cable from the preamp or the power amp (Mullard5-20) it provides a nasty shock. Mullard did not mention this; but Stern built the same preamp and clearly stated that there will be an electric shock from audio cable when the power amp is on due to return current via the audio cable shield.The return current to the power amp is via the audio cable shield. Is there another way to the send the returning current to the power amp? For example, could I use the umbilical power cord, and how may do this. I am a novice;no complicated solution please.

Im only getting rail voltage on half of the outputs .

Q2011,2014,2008,2006 have no tail voltage on any of the legs .

Any ideas ?

Hello together, I hope i found the correct topic for that.

I'm currently working on my own AV-Receiver (6 channels => 5.1). In order to apply the method divide and conquer, I split the whole project into 6 subgroups, e.g. Power-Supply, Front-End, Power-Amplifiere, DAC, etc. As the PCBs for the Power-Amplifier are ordered right now and have to wait for approximately 3 weeks until they arrive, I started with the front-end in parallel.

The plan for the Front-End is to use SPDIF from my TV (and later on split the HDMI-Signals via an ADV7612 Chip). Therefore, I work on a evaluation board to get used with several Chips (CS4816, DIX4192 and the STM32H750). All of them are capable to decode AES-3, but not AC3; (I want to try different Chips to see which one works better for me). And that is the point where my struggle begins. And the question is simple, how works AES-3 and AC3 together and where is the difference to Dolby-Digital (maybe encryption?).

In order to check, whether my TV is sending something, which i can receive, i already tested a receiver and had a look on my oscilloscope, saying we have a datarate of approximately 6 MBit/s. However, as I understand it correctly, AES-3 transmitts only stereo-data divided into blocks/Subframes/Channel (A/B). Even with 24 Bit and 44KBits the 6 MBit via SPDIF is way more than AES-3 would require to transmit only stereo data (maybe I'm something missing). However, the next thing is, the manual of my TV says only 5.1 data is transmitted via SPDIF, which should be AES-3, right? As far as i understood it correctly, the AC3 data is transmitted via AES-3 but i didn't found more details on how they do that, the DIX4192 for instance is capable to detect that AC3 data is received, but once more I'm confused how AES-3/AC3 works together or how the synchronization is done to the video signal of the TV.

Furthermore, I read alot of Dolby-Digital and most of time i read that it's "only" AC3 and nothing more. Other websites say it is something complete different to each other and others are also claiming Dolby-Digital is equal to AC3 and DTS, thus I'm sitting here with a big question mark over my head 😀.

It would great if somebody can shed some light into the dark (maybe with references, so I can read more about it). Sorry for my stupid questions, right no I feel pretty dumb about it...

Thought I check out the car audio forum to see if anyone built their own power amp.
But I cant find any any one have a link to diy poweramps ,class AB or class D.

Hi,

Looking for some guidance to replace the Red power indicator lamp on the front panel of a late grey model Quad 405-2 with a Blue one, possibly an LED. Having searched for component values and/or a wiring diagram of installation to modify to Blue there appears to be little information. Maybe other 405-2 owners have successfully fitted different coloured lamps and could offer their advice.

Many thanks,

David.

Hi,

I'm looking for a balanced input, 24dB/oct infrabass (cca. 20Hz) HP filter to protect the vented subwoofer under the operation freq.

Is there any available to buy somewhere?

Or a schematic to start with?
I found some subsonic filters, and LR filters or balanced ones, but NONE that have ALL, in one solution.

Passive or active, no problem.
Thanks for any advise

I managed to pick up a TCWA9ES at a flea market recently and now getting around to servicing it. Prior to doing so, the A deck door was stuck closed.

After first observing, it looks like the reel motor is not working at all. I broke out the volt meter and I am not getting any reading from either the working and non-working reel motor solder connections. When the open button on either deck is pressed, the capstan motor turns both flywheels.

I have replaced both belts on each transport, with the B transport functioning as normal.

I tried resoldering the capacitors, connections and motor plugs to no avail. The capstan motor still turns on both when the working is pressed, but not te other way around.

Parasound "C/DP 1000" (CDP1000 C/DP1000 CDP) CEC 2100 3100 Service Manual wanted

I am looking to a service manual of those associated CD Player model, where the here showed servo/pcm decoder PCB from Sanyo Optronics is in use:
???? - ????????????? ???????-??????, ?????????? ? ?????????? ? ???????.

Only schematic diagram of this PCB I have found by post #7 and #8 about
http://www.diyaudio.com/forums/digital-source/163081-cec-tl51x-cd-transport.html

There are a lot of other brands, where this PCB is in use. I have attached some pics and listed some examples by post #5 about
http://www.diyaudio.com/forums/digi...a-classe-cdp-3-roksan-caspian-main-board.html

The there mentioned models (Sharp CD S600X and CEC 780CD/880CD), from that I have found service manuals, are helpful, but not perfect. Therefore I want to have a service manual of those cd player device or hifi system, for which this PCB originally was developed and used. The following identifier numbers are to read:
1) on the PCB: "TK-T71 94V-O" and "4B10012700C"
2) on the associated schematic: Sanyo Optronics CO., LTD

My experience has shown, that there are more detailed adjustment and troubleshooting instructions.

Who know the associated model ?

A set of Printed Circuit Boards and hard to find IC's for the Elektor Electronics construction project "DAC 2000".

Full set of pcb's and the programed GAL and the 2 x 1704's.

Unused and all in great condition.

Price is £25 or $34 + Postage



Contact me if interested.

This isn't specifically about a subwoofer but it's about bass so I thought this might be the best sub to put it in. I'm nearly done with a two way system I'm building. It uses two 8" woofers in separate enclosures. The woofer on the left works perfectly, outputs bass accurately without distortion. But the one on the right, has this port noise affect? I know bass is omni directional so I'm not sure how accurate I am when I say this, but it sounds like it's coming from the woofer and not from the port, which is why I'm not sure it's port noise. It also seems to be there at all volume levels. When I plug the port though, the noise goes away. So, what's my issue here? Could there be a woofer issue, or is my right port not sealed to the enclosure properly somehow?

Hi all,
My Martin Logan Dynamo 500 subwoofer only has an "auto on" switch.
I would like to add a dedicated on switch.I have the schematic.
Thanks much

I'm wanting to build a microsub with solid bass extension keeping the form factor as small as possible while getting near the 30hz range -3db.

Driver choice:
W5-1138SMF

Passive Radiator
Wavecor PR182BD02 7" Black Aluminum Cone Passive Radiator with 70g added mass

I'm modeling three sizes assuming 1/2" stock
8.5" cube (~6.91 l)
9" cube (~8.4 l)
9.5" cube (10.09 l)

F3
8.5" ~ 34.75hz
9" ~ 32hz
9.5" ~ 30hz

Knowing that I'll lose some volume I'm thinking the 9" or 9.5" cube is the smart choice.

Considering powering with Lepai LP210PA plate amp.

Do my winisd calculations look correct? Any better choices for a small form factor subwoofer for driver and passive radiator to get down near 30hz without chuffing?

I don't need to win an SPL competition, I have UXL-18's for handling the heavy work. I need something I can discreetly place in a room and garner WAF.

Anything I'm missing?

LME49720

The data seems identical to LM4562..is there any difference?

Hello everyone,

I wonder if somebody would be able to help with the schematics/service manual (all expenses will be reimbursed, please specify) for the following power amplifiers :

Inkel MA-620; MA-910

Jeil BST JMA 600N, JMA 900

Furthermore, I'm looking for the schematic for TOA ZM-103 Impedance meter

Kind regards, JF (P.M. = J.Franken@Telenet.be)
Thank you for replying.

I've tried Moode and Volumio so far. Each has run me round the track chasing my tail a few times now; Moode works best so far - but wont show my album artwork. (I've got a thread going over at their support forum)

I had Volumio all set and working - album artwork showing - until I tried to add the graphic eq, which then killed the signal to my AMP2. Removing the graphic eq "plug in", in an attempt to go back to a previously working system resulted in the file directories for the ALSA soft volume not being found.

A flash card rebuild and start from the beginning resulted in it claiming my samba share was off line... When on the previous fresh build / startup, it found it immediately and connected perfectly with no additional input text details from me. Scratching head, I quit it at that point and went back to Moode...

Can these MicroSD card resident systems somehow store NV information on the pi itself? The Moode player "remembered" a login name I'd previously typed - even after a full sd card reflash_and_start_over. I suspect the inconsistent behavior from Volumio regarding the samba share connection between "flashes" could be related to this.

So, what's a player that "just works", when using -

- A Web page interface for volume control - and everything else
- A pi 3B
- A HifiBerry AMP2
- An active graphic or parametric EQ?
- A samba share mounted via wireless (to a Netgear R6300V2)

I'll start off by guessing ALL these players have such problems and there's no such thing. Is there something that needs to take place that would otherwise prevent, say, being able to simply swap different players in/out using different MicroSD cards?

Thanks!

The 6DQ6B is a tube that pops up time to time on this forum (usually in threads praising the virtues of TV tubes) but I've yet to come across many examples of projects built around this tube. On that note, I would like to present my latest completed project: a 20WPC stereo amp that uses the 6DQ6 in push-pull triode mode.

The goal of this project was to make a reasonably powerful stereo amplifier that made use of a power trafo and two HH Scott OPTs that I'd been trying unfruitfully to find an application for. The OPTs are 8K a-a with 4, 8, and 16 ohm taps; originally paired with EL84 tubes. I also had a bunch of 6DQ6Bs lying around from a previous failed project. In my experimentation, I found that using 8 ohms across the 16 ohm tap provided a 4K load that a pair of triode-mode 6DQ6Bs seemed to like. Despite warnings about screen grid max voltage ratings, these tubes seem to play nice with only 300V B+. At a quiescent OP of 50mA per tube, the bias is upwards of -50V and the plate dissipation is 15 Watts.

I don't have the means to test the distortion or frequency response, but I can say that this amp sounds quite good to my ears. Then again, nothing sounds better than an amp you built yourself 😀 For those interested I've attached the LTSpice sims and some more explicit schematics via PDF. Hopefully one day it might be of use to someone who also has interest in this tube.

Hi,

Not sure how to call that in English: a hole that is not going all the way through.
I would like to insert a LED in such hole in order to have some indicator that the power is ON. The panel where the LED is supposed to fit is made of black plexi (8mm thick from toroidy.pl). Wondering if the light of the LED (12V model) will be visible by leaving few mm of plexi in front of it.
Has anyone tried that? How much plexi should remain in front of the LED (1-2-3mm?)?

I have four Kendiel screw top capacitors for sale.

£60 plus shipping and paypal gift please.

I am thinking of making my own speaker

Basically the key here is dimension

2x2x1(LxHxW)

Drivers are initially 6.5" full range and 8" full range

6.5 fullrange covers tweeter and upper midrange and will be sealed in top portion half way.

8" will be lower midrange and bass >30hz and with passive reflector in halfway.

Back half of speaker will be Transmission line and vented at bottom of speaker

Transmission line portion need some work in design so its in phase with front woofer.

My idea is instead of venting with boom let passive radiator take some of work.

Also when when air moves with ported there will be differential pressure inside. With passive radiator air will be in equilibrium so no distortion.

Let me know speaker experts think

First half box is speaker box. Second half is transmission line.

Selling
Dual Mono ES9038Q2M DAC + ESS Controller + ESS Controller Extension Cable + IV OPA board
original price is 171, Asking US105 + Shipment
The output transformer of dac is from
Output transformers for DACs
already with Vishay Foil Resistor, have RCA and XLR output
original price is $170, asking at 110 + shipment
Location: Hong Kong

Please PM

So i’ve been pondering fundamentals of mixing and how the process interacts with the working space acoustics and directivity. Modern fullrange drivers leave one thing on the table,......the inevitable poor off axis response......

.....which i have been considering a blessing for nearfield use in a ‘not so ideal’ listening space......reduced smearing and early first reflections. All that would be left to augment focused wide range in axis response would be the low end.....a larger driver that works well in a sealed enclosure with a fast impulse response and response to 35hz......I need to hear HP filter applications on drums and bass guitar.

Thoughts?..........

Anyone familiar with the FFA200 amplifier as published in the Tech/Elektor electronics book 'Build your own High-end audio equipment'

I'd like to give to my lenco 75 an isolation by four pneumatic springs ,
I'm from Italy, and I've only found on the RS catalogue the "FABREKA isolation feet " catalogue number is 688- 486 . Those pmeumatic springs could work, but the load is 45kg for 1 feet . My Lenco weighs 20kg . My worry is that with such load , bass extension could suffer a bit . I'm not deep in pneumatic isolations and related questions. Could anyone advise me what springs could be the better solution for my LENCO ? What could be the ideal load for my purpose ?

I'm sorry for my little english

I started my DAC project for the Raspberry Pi. The first version runs as an I2S slave device and already works very well. On-chip PLL automatically syncs to different clock frequencies. Analog power is supplied by an additional low-noise voltage regulator.

HiFiBerry Mini | Crazy Audio

I will do more measurements next week.

Version 2 is in design phase. It will be a bit more complex:
- onboard oscillator, runs as I2S master
- DAC chip with I2C control (volume control, sample rate, minimal DSP postprocessing)

Regards
Daniel

Hi Gents,
Anyone here happen to know the specs on the above ?

Thanks

This thread is for discussions about everything to do with the many possible Burning Amplifier configurations.In general, there are two output board types. BA-1 and BA-2

Articles:

• Burning Amplifier 1
• Burning Amplifier 2
• Burning Amplifier 3

Other Materials and Guides:

• Burning Amplifier Configuration Infographic
• Board Mounting Specification

Discussion Threads

• Burning Amplifier 1 Discussion Thread
• Burning Amplifier 2 Discussion Thread
• Burning Amplifier 3 Discussion Thread
• Burning Amplifier General Discussion Thread

hi -

can anyone tell me the relationship between the diy audio store and first watt? Is the online shop the only place where I can buy first watt boards? I have had some bad experiences with their quality control and i would like to buy from a store whose staff are knowledgable with electronics if possible.

thank you very much

Philip

Selling 8pcs new 10,000uF 63V DNM 4TTN capacitors for a colleague who has no diyaudio acc.
Please PM if you are interested.