Hi,

Recently acquired a Leak Stereo 30 plus with only one channel working and I find that 3 transistors are defective on the power amp board.

A resistor also looks suspect (burn stains around it) so I will be checking these too. Looking at the resistors I see that 5 look different from the other conventional axial lead soldered into the boards, these seem to have vertical metal tabs. Could they be wire wound? I would appreciate some advice on this please in case I need to renew some.

Also, does anyone know the type of resistors used on this board in addition to the ones already mentioned? The circuit diagram gives their value but not the wattage.

I’ve included some photos of the board which I hope will help.

Thanks,

I’m trying to understand woofer specs to choose a suitable woofer, it feels very confusing with all the parameters effecting each other.
My fixed variables are large sealed cabinet (200-280 Liters) 2 15” woofers in a MEH design built around the Klipsch large K402 horn, and only need woofers to go up to 600 hz.
Looking for lots of articulation and subtlety, not for ultimate low end extension.
I’m trying to understand the relationships between qts, cone mass, bl, xmas, etc.
Any perspective on how to choose a suitable woofer would be appreciated. Thank you

I’m building a very simple omnidirectional speaker with a bass/mid firing upwards and tweeter firing forwards. Its now time to take some measurements in order to model a crossover, but I can’t decide how best to achieve this. I can measure in the garden, either well away from surfaces or up against a wall to introduce 2 reflective surfaces, or in a room to include all surfaces. But, because of the omnidirectional nature of the sound waves, I can’t decide how best to capture them. How do people normally approach measuring omnidirectional loudspeakers?

How does one wire a balance control? Since I now know where to get a dual-gang log pot, I'm thinking of getting rid of the dual volume controls on my amp and having a volume and a balance control. Is a balance control done with a dual or a single gang pot and how do you wire one?

Hello everyone,
Here is the situation in a few words :

• I just want to have a slightly better sound when watching TV and being able to listen casually some music in Bluetooth
• I have been given 2 small speakers Yamaha NS-E7900 (40W - 6ohms) and a subwoofer Sony SS-WS53 (??W - 1.5ohm)
• I am not an audiophile, I just don't want pops and hisses
• I don't want to listen to music or TV loud, I don't particularly hate my neighbors and they don't particularly hate me either, so I would like this to continue
• I studied electronics, I have some equipment, but I have never played with audio before
• I live in Taiwan and I have easy access to Aliexpress, Taobao (equivalent to Aliexpress but for China only), Alibaba, etc

So putting all together, I have been searching for a solution for a 2.1 amp that would be compatible with my 1.5 ohm sub. Not easy.
According to my research, the TPA3116D2 and TPA3118D2 can drive a speaker of 1.6ohm in PBLT.

I have a few options :

• Sure/Wondom JAB2V2+JAB3 (+FreeUSBi if needed) = 62 USD with cables
• Sure/Wondom DSP board+Extension board + 1 stereo amp + 1 mono amp + 1 BT receiver (+FreeUSBi) = 40-50 USD
• Midiworx ADAU1701 with BT + 1 stereo amp + 1 mono amp (+FreeUSBi) = 30-40 USD
• Arylic Up2Stream 2.1 amp (+their software at 20USD ?) (but given for 2 ohms min) = 119 USD
• Tinysine TSA7500 (but no way to set the get an equalizer) = 65 USD

For the mono amplifiers, I have seen quite a few in TPA3116D2, such as :

• XH-M542 (100W mono) for 3 USD ?
• XH-M544 (150W mono) for 4.1 USD ? (no impedance noted)
• Unisian (150W mono) for 15 USD (4 ohm impedance min ?)
• Sanwu 2x50W that can be set in PBTL 100W for 12 USD

It is about the same for stereo amplifiers.

So here are my questions :

1. Which route would you go for ?
2. Is it as simple as putting the elements together ? I don't mind soldering etc, but if there is any passive components, I don't know how to pick them.

Thank you very much for reading all of it. Sorry if these questions look stupid, but I have already spent countless hours on this forum and others, reading everything that may be relevant including cryptic datasheets (some in Chinese for BT modules...) and I am still not sure of how to approach this.

As the title says, my first experience and wondering is this is normal.
This is an ebay amp, from China, so I wasn't expecting greatness, but so far the sound from it is pretty good to my old ears. Totally silent with not signal input too.
My questions,
1, Should the output filter coil get hot? After about 10 minutes of listening at fairly low volume, I'm sure less than 10 watts, the coil was around 130 degrees F. Is that normal or will the coil eventually fail, short or would it be ok?
2, I see about a 1 volt p-p sine wave across the speaker terminals, even with nothing playing. It is at the the switching frequency (i think 500khz), so way higher frequency than the speaker can produce and any normal human could hear, but would this cause unnecessary heating in the speaker voice coils?
3, It has a built in speaker protection relay but it doesn't turn off immediately when power is turned off, it continues to produce sound until the caps discharge a bit, then turns off. Sounds like poor design to me, but what do the experts think? It does delay turn on about 3 or 4 seconds after power applied, so that part is ok.
Thanks.
Glen.

I have a pair of Westra woofers KW-160-1314. Are they any good? I can't find any info anywhere or should I bin them.

FS, various mains transformers pulled from vintage amps etc, most are very good quality 70's Japanese jobbies with copper flux bands. I've tested them all under load and given figures are conservative.
1)35v 0v 35v 3A + 0v 24v 1A
2)0v 24v 2A + 0v 18v 1A
3)Tfmr off a MarantzPM143
4)20v 0v 20v 3A
5)Woden 30v 0v 30v 2A
6)0v 18v + 0v 28v 3A + 2.5v 0v 2.5v 300mA + 18v 0v 18v 1A
All five pounds each + £3.50 postage except # 6) = £6 est.
Drop me a PM if interested, Andy.

Hi all
Stetsom with 2 irs2092 Ic. Two channel input with one speaker terminal output.
One ic has 42% duty cycle and the other has 47% duty cycle. Will that make any problem for the amp to go into protect after playing a minute or less?

I'm getting ready to build a new workbench for the winter silly season of building madness and am in the process of digging out all of my test gear etc.. One item I restored and calibrated a few years ago is a really nice Tektronix 575 curve tracer, but it's approximately the size of a house and I would have to make a rather large space to accommodate it. I know we can static match Idss and such with a simple DVM and test jig, just wondering if a curve tracer would be of benefit for matching JFETS, MOSFETS and SITs (if I ever find any) .

Thanks all,

Cheers

Do you know any? I think I can go with KiCAD but anyway

Hello and welcome to the Jugs MK II. It's been 10 years since the first Jugs shocked the world. Super Store was once again the inspiration: there must be someone there looking out for me. Any way down to business. These speakers come as a complete system. Starting with an SMSL m7 DAC driving a Breeze Audio Linkwitz Riley 2 way 24dB octave 2KHz crossover and 2 Breeze Audio TPA3116 Texas Instruments Amps(Bi-AMPed). Power comes from a Phoenix Contact Trio 24VDC/10A power supply.

The speakers are built into a 7 liter jug with a 5cm x 20cm (2" PVC tube) port (60Hz). I'm using the a SB Acoustics 5" PolyProp speaker sb15mfc304 with an Eton 26 HD 3 tweeter.

So what's the big deal, I had to post this. Well the bass extension is down to 47Hz! and they don't seem to screw anything up. These babies are inviting the neighbors over to party. LOL I got everything at ebay, Solen, Amazon and Super Store ~$1100 Canadian

Tweak monkeys can swap the opAMPs, and adjust the supply voltage.
I would crack rebutter the TPA 3116s.

Have a nice day.

I have a Peerless 5" 8 ohm mid range that is made in Denmark. I purchased this in 1997.
I am looking for the specification sheet for it. The markings on it are as follows:
5445
69'98X u8

I also have a CTS 10" 8 ohm woofer that was purchased in 1997 as well.
I am looking for the specification sheet also. The markings on it are as follows:
10W14P
8 ohms
7628

Any help would be greatly appreciated.

I was wondering if anyone had any suggestions on what sub I should get for my Silverado single cab, around a 400$ For both of them. I already have a amp and I was planning on getting this box. The amp is a Skar SKv2-1500.1D and I was going to get this box with a Mounting Depth: 6.25", Volume: .85 cu.ft. Per sub. I was originally going to get two alpine R2 10” subs but I wanted to know if anyone had any other suggestions. I was already suggesting getting two audiopipe TXX-BDC3 10” or two Skar SVR 10” or two NVX VCW104V3.

​

Hi there, my marantz cd10 display problem , I insert cd disc total tracks can be displayed, can also be played ,only the cd dics total time cannot be displayed.As long as I turn off player and turn on player again ,after that can show the cd dics total time .what's happening to this problem . Hope someone can help. Thanks

I was suggested that if the subwoofer crossover was set to below 100Hz, there should be set the operation to mono mode. The stereo mode should be used if crossover frequency is above 100Hz.

What if I use two subwoofers but set crossover at 85 Hz? Should I use Mono or Stereo mode on these subs?

I love the new site and have promised myself to post more
I was fascinated by bass when my uncle played lily the pink on his philco gramophone in 1967 ,the bass notes made me dance to every ones amusement,I was 3 and my love of bass never went away
But this article proved a good point and I wanted to share
https://www.cell.com/current-biology/fulltext/S0960-9822(22)01535-4
Have fun

Those interested at getting these amplifier modules at $90 mono can show their interest here. Shipping is on average $20 world wide, actual cost will be communicated based on shipping address. You should have these in December 2022. I will email the actual schematic used for the module on request. PM me for mode of payment including PayPal.

Grant RIAA Phono with 12ax7/ecc83

I received this phono amp as a gift from a friend who had given up on trying to fix it. I was able to repair it and was surprised at the sound quality.

I have a power schematic that rates the B+ at 250 but the actual power supply in the amp delivers a solid 340 volts. It does appear to be all original too...

It uses 3 ecc83's per channel and has very nice sound despite the seemingly incorrect B+.

There is no gain problems, but a bit of humm when I use it with MC especially.

I was just about to adjust the 470 Ohm and 47K input resistors to match for cartridge impedance but would like someone else to look at the circuit first. I want to do this without changing the characteristics of the RIAA curve of course.

Thanks
soulemerchant

I thought I could say a few words regarding my initial impressions/experience with my new subs.
I bought these for my OB design, to replace the FaitalPro 15FH510. The Faitals were good drivers overall, yet having Fs at 35Hz they really needed some help to cover the frequency down to solid 30 Hz. So I needed 10'' sealed subs to be happy with the sound of my OB.
The goal was to get rid of the sealed subs. I started to look for 18'' drivers, with a decent Fs and a solid construction. After all I decided to go for well-regarded and expensive BMS 18N862 and I almost bought them... Then searching for them I accidently found the Biancos... They were suspiciously cheap (you could have 4 Biancos for the price of 1 BMS) but... They are manufactured by the pro division of SB Acoustics and I always regarded them as a reliable company. Next, they had everything I needed: low Fs, cast aluminium chassis, copper as winding material, decent Xmax of 11mm... relatively low power handling (450 AEs) didn't bother me as they were intended for home use.
So I decided to give them a chance and regret later...

Let's start with the looks: they are good looking, and I mean both sides which can be important for OB. The front side of the cone is uneven under the coating which is looking good, real-like, not a cheap plastic glossy.
Overall construction from the first looking/touching seems very solid, nothing alarming there.

Now the sound. First of all I don't listen very loud, max 90db at the listening spot, I think 100dB if you add peaks.They play in 50cm wide U-frame Open Baffle. The front pannel is 36mm plywood, the U-frame is 20cm deep. Their duty is to play up to 100Hz where they give over to Faitals 12PR300. They are driven actively (minidsp) with, obviously, a lot of eq. I wondered how hard I could push them only to find that... yes, you could be brutal and the Biancos didn't mind. Of course, every driver can be damaged if you try really hard... just saying that I had them pushed 24db at 25Hz and they didn't show any weird behaviour like suspicious noises, vibration, etc.
The sound is pretty much like I wanted to have. Substantially deeper then the previous 15'' Faitals so I got rid of the sealed subs.
And hey... they are still fresh, so after they break-in I'll be back to give you more info.

What are some good practices to use in calibrating one mic with another calibrated mic?
Assume mic sensitivity is not important, only frequency response is.
Some things I wonder about are:
Does it matter what kind of speaker you use to compare the mics?
How full range should the speaker used be?
Does gating matter?
Does stimulus type matter?
Any input is appreciated.

My Dual turntable has begun making an occasional mechanical clicking sound while the platter is spinning. The noise seems to only happen while the platter coming up to speed. I’ve noticed it happening shortly after turning it on and after using a dishwasher brush to gently clean a spinning 33. Any ideas?

What is this used for?

It has the look & feel of a vintage oil filled capacitor.

It appears to have an input side, and a separate output side.

Is it a capacitor, or a transformer?

What would it be used for?

Has anyone measured or got the specification for the ESR of the ASC X386s capacitors, I have asked the manufacturer and after 2 weeks of 'sorry we are taking so long, technical is busy' I thought I would ask here. I want this to confirm a PSUD2 simulation to select the sizes to purchase.

Thanks!

Hey guys

I am aware this has been covered before in a previous post,

http://www.diyaudio.com/forums/showthread.php?s=&threadid=126430&highlight=cw2108

but unfortunately I am not too clear on the final application as I am pretty new to pro audio.

Ive built countless sealed sub enclosures for car applications, so my woodwooking skills are not too bad, but I have only grasped the theory of advanced box design for hifi. I have been reading this forum for a long time.

So... in my possession I have 8, yes.. 8 of these cw2108 jaycar drivers. I would like some advice on what enclosure design would best suit this speaker, possible volume and port sizes etc. I plan on using them for home theatre hifi and music (well obviously) mainly electronica like infected mushroom etc.

I plan on buying some soft dome tweeters from Altronics, as they are relatively cheap


(hopefully not too nasty) but im mearly matching the quality of the woofers 🙂

Anyhow, i was looking at this design
[URL=http://www.humblehomemadehifi.com/LBS.html[/URL]
i like the look so long as these woofers can handle a bass reflex design. I am not an audiophile by any means, but I do appreciate good overall sound from a system. PLus this box looks easy to make.

Oh and ill be attempting my own crossovers too..any quick advice on that would be great also

Any help is greatly appreciated

Kon

What would cause these 0.1uf caps to burn like this ?

Also when this amp is hooked up in the vehicle it burns the ground shields inside the head unit

I tested for voltage on the rca shield grounds of the amp and get no voltage

Just found the review of the recently released Topping DM7 8-channel DAC on audiosciencereview.com:
https://www.audiosciencereview.com/forum/index.php?threads/topping-dm7-8-channel-dac-review.35661/

The performance level is very high. Output levels up to 5Vrms would pair nicely with PFFB class-D amps that need that kind of input level. Currently available for sale at $599.

This should be able to work under Linux and be used as a multichannel DSP crossover sink. I have not seen a confirmed report of this, and the recommended kernel version, but I am very optimistic about it. The only downside is a lack of input of any kind, however, you could use CamillDSP and another interface that is dedicated to analog or SPDIF input, or just use sources that are accessed via the computer (files, web streaming, etc.).

This is on my radar along with the MOTU Ultralite mk5 (priced similarly at $595), which was also reviewed at audiosciencereview.com but has been plagued with delays due to the AKM factory fire. Hopefully available this fall using ESS chips instead. The MOTU unit has 10 balanced output as well as analog and digital inputs, Overall the Ultralite mk5 is lower in performance, however, the difference is really down in the weeds IMO. Pick your "poison". 😀

I'm going to hunt for electronic stuffs in Singapore next month (I couldn't
yet figure out a cheap place/hotel to stay). May be I want to buy Lundahl
transformers or Lowther drivers or Seas Excel or something.

What is the place for hi-end electronics components in Singapore? In
Sim Lim Tower, where can I find such stuffs?

Hello,

im using CamillaDSP on my Raspberry PI for room correction for my Active Speakers that go down to around 40 HZ (-/+0db) and wanna consider buying a Subwoofer down the line to go down to around 20hz

my question is, would it be possible to buy a active studio type subwoofer with crossover built in (so you go with Stereo XLR into the sub, it handles the crossover and go out with XLR to the main speakers) so i can actually build a 2.1 system that is DSP corrected with just a 2 channel dac? or would it be far more beneficial to go with a multichannel dac so i can DSP the subwoofer seperately?

Here are three gain circuits. To put aside any references to different historic periods and schools of design they are implemented using abstract transconductance devices. I have cheated here: you can't put ideal current sources in series so keep in mind that they are real world devices like transistors or tubes.

A


B


C


They all are actively loaded gain cells. Their active loads works on the same principle: by maintaining constant voltage drop across sense (feedback) resistor(s). Circuit A is a classic CSS loaded gain cell. It works by maintaining the sum of the gain device G2 current and the load current constant. Circuit B is also a CSS loaded cell but in a more pure (?) form where the gain device G2 current is kept constant and G1 accomodates all the the load current swing. This is what is known as SRPP in the tube world. Circuit C shares the load current between G1 and G2 in a push-pull manner depending on the resistors ratio.

The question is how would you call this generalisation and those three special cases?

All sold.


About a year ago I bought from Jan the "New, upgraded Autoranger AR MKII V3 semi-kit" but never did anything with it. I opened the box but haven't done anything beyond that.

Accepting offers


Also, I offer an oscilloscope from red pitaya for 50 pounds.

Hi
I read somewhere that it would be beneficial to make lowpass for the tweeter.

I think the idea is to make it smoother sounding by reducing intermodulation distortion that can affect the frequency response down hearable range, and reduce tweeter range it has to play.

Any experience, good idea? Yes, no?
If one were to use it, how high it should be used to have effect on hearable range?
(reduce distortion)

My longtime favorite tube amp and one of my first builds is my SSE that I built in 2006? With the cooler weather setting in, I swapped out my summer Class-D amp for the SSE and it's been getting some heavy use when I've been working from home.

Yesterday I flipped the switch on the SSE and after a few moments the chassis gave off a strong hum and then popped it's 4A fuse. No smoke, just some short somewhere. So it's troubleshooting time!

Tubes and speakers check out OK. I'm guessing I'll check the transformers for shorts, and if nothing found there I'll have to remove the board and trace it out. I should have all the spares I need. Let the adventure begin...

Hi, would be posible to use lundahl 1671 IT like plate load ( 35H) for a d3a tube ( 1.7k plate resistance) and RC coupling to 300B?

https://www.madisoundspeakerstore.com/seas-soft-dome-tweeters/seas-excel-t35c-002-35mm-mid-tweeter/

Like the even more pricey Alnico magnet version, this one is rated down to 1500 Hz. Has anyone used it in a 2 way system and have comments on the performance?

Thanks

Looking for the above card for my 861

Thanks

I remember seeing some schematics for "two wire" active electronic chokes that can be "dropped right into" the choke position of a pi filter. But its an all electronic choke that runs in series like a regular choke. Tent labs makes a commercial one, so something similar to that I can make myself.

Well, I can't for the life of me find those schematics again. Does anyone have such a circuit they can share? 50 to 100 ma 150-400 V that can simulate 10H electronically is what I'm hoping to find. Thx.

- with many thanks for CAD work by TB46 (2D) and Pelanj (3D models), I present for examination 3D files for the popular Karlson type cabinet known as “The Dutch K12”, which was introduced In a June 1963 article titled “Karlson Luidsprekerkasten voor Kleinbehuisden”

https://www.diyaudio.com/forums/full-range/313227-dutch-karlson-12-a-2.html#post6473774

This cabinet’s front chamber resembles that of Karlson’s 1st K12 (introduced fall 1954) and rear chamber that of the 2nd K12 (fall 1956 plus featured in July 1958 Popular Mechanics.

It sports 3 horizontal slots as a distributed port.

I and other Karlson fans would be very grateful for a thorough Akabak3 examination of this cabinet. Items of interest would be 2pi frequency response on and off central axis, frequency response at some distance back and “up” from the cabinet’s central axis, input impedance, cone excursion, and group delay.

Drivers of interest = Fane’s twin whizzer 12-250TC and Eminence’s 12LTA.

Details of just the Eminence 12LTA would be plenty - I would like to see what 12-250TC does for peaking on the low end.

Also, it could be interesting to see what things look like with the port shut off.




Def_Driver ‘12-250TC’ | Fane 12” full range driver with extended highs, 3.5mm xmax
Sd=530.9cm2
Fs=50Hz
Mms=52g
Qms=7.6
Qes=0.72
Re=7.2
Le=0.156mH
Vas=78.06L


Def_Driver ‘12LTA’ | Eminence 12” whizzer cone speaker, xmax 3.2mm
Sd=532.4
Fs=45Hz
Mms=36g
Qms=6.44
Qes=0.55
Re=7.73
Le=0.83mH
Vas=135.3L

Ars Technica, incidental to a back-end revamp, is boasting of the age of their fine forum.

"Community is vital to Ars Technica
"When longtime Ars readers talk about how long they’ve been around they often point to their forum registration date (mine is June 8, 2001). It can be a badge of pride!...."

Don't we have some similarly long-term members here?

"In an era where many sites are closing their comment sections, and social media increasingly treats people like a commodity, we’ve chosen to refocus on how we can amplify the great contributions readers make here. To do that, we needed an entirely new forum and commenting system, and we’ve found it in XenForo, a modern forum system with a familiar feel."

It's going to be all sweetness and light at Ars Technica. 😉

G'day folks.

I have an interest in acquiring an Aikido line stage for preamp duty.I presently am using a Transcendent Sound Grounded Grid preamp,and I am very happy with it.It is being used in an otherwise entirely Solid State vinyl-based stereo system.

I was considering upgrades to the Grounded Grid.Research on the 'net yielded the result that I would be better-off purchasing an Aikido line stage.

Now here is the reason for my post here;I have no experience of construction(I had the Grouhded Grid constructed for me),nor do I understand the finer points of tube design theory/practice.Thus I will necessarily be getting someone to construct the Aikido for me.I am seeking advice here specifically as to which of the many Aikido options yield the highest sound quality.

I am not looking for an Aikido which will add a 'soothing' or 'warm' sound to the system.Nor do I seek euphonics.I am looking for a line stage which accurately reflects/represents the signal which is being fed into it.A 'High Resolution' quality is what I am seeking.Greater insight,both sonic and artistic,where the software provides both.

Which power supply options also support the best version of the Aikido?

Is there a version of the Aikido which comprehensively outdoes the others based on this criterion?

Hello all, recently picked up used Schiit Bifrost 2. DAC was well packaged but not in the OG box so it had room slide around a bit in the box and must have gotten tossed around pretty hard as the toggle power switch on the back too a good hit and is pretty finicky. It works but I don't really trust it.

Schiit said they can fix it for ~$100 out of warranty but if its just a damaged switch its probably something I can replace for $5 as I've built crossovers and have done a bit of through hole soldering. Unfortunately Schiit won't provide any support even to the extent of saying what switch they use, so I'm not exactly sure what I need. Its a right angle toggle switch with three legs so I think makes it a SPDT, on-on? I'm not sue what series though or how that even works?

Here is a picture of the inside of the Bifrost.



Digi-Key has a bunch of switches that look to be of the right type and the switch I'm looking at is E-Switch 100SP1T2B4M7QE (Its a right angle through hole vertical, 100 series SPDT) and looks to be identical but again, I'm not 100% on what I'm looking at. Am I on the right track here?

I am a final year high school student who spends all my free time listening to music. I genuinely listen to everything you would be hard pressed to find a genre which I do not enjoy. I have been listening on headphones and IEM's, however I have always wanted speakers and I now have a part time job to pay for them. I would like to build a pair of speakers of some sort probably with a full range driver because it seems the least complicated. They would be in a clutterred living room in front of a bookshelf and then probably in a dorm in a years time when I go to uni, so I probably shouldn't build something too big.
I dont listen to music extremely loud so volume isnt that big of a deal although bass quality is as I play both bass guitar and upright bass and I would like those instruments to sound rich and full.
I dont plan on buying a kit as I am a student and saving for uni and I dont mind a bit of woodworking as long as its nothing too crazy.
I have been considering the frugel horn mk3 although I am not sure which driver to use. Would this be the right build for me? If not what would you reccomend?

For this amplifier, I need a little bit help. I don't understand the meaning of Q12a. There might be even a misprint Who knows more? Maybe "X-PRO" ?

Newbie question.
I am running my TL2 (Troels Gravesen The Loudspeaker II) using Line Magnetic LM-216IA valve amp. Great amp, wonderful speakers... but!
Is there any sonic adventage/ difference/problem/risk connecting this 8ohm rated speakers to the 4ohm output?

Thanks, and if your start throwing tomatoes at me, please make sure thery are overripe 🙏🍅

I have these two working Sony units (1982?) and was thinking of replacing them.

Might it be a good time to replace them with something similar or just keep using them for another 20 years?

Can anyone recommend a reliable brand but not in the high price bracket? (< £300 )

I recently upgraded my Amp Camp to an F5 so I no longer need these parts. The amp boards I put into another project but am selling the PSU and transformer.

- 2 of Rudi Ratlos’ CapMX PSU boards (one per channel)

- 1 Antek AS-3222 transformer.

All parts were removed working perfectly. I just wanted more power from the F5 and decided to move on from these parts.

The transformer with these CapMX boards provide up to 28V and can be adjusted down to 25V if you do not have the heatsinks large enough.

Asking $100 and I’ll ship for free anywhere in the CONUS.

Just for interest,

What is the Universe Expanding Into?

And

http://preposterousuniverse.com/writings/cosmologyprimer/dark.html

A poll has been set and it is multiple choice the poll is on going...please read the thread before voting..

Regards
M. Gregg

I am looking a remote control with display to implement a Transformer Attenuator 24 step.

http://www.sacthailand.com/Transformer_Attenuator.html

Out of eight KT-120s (four old & four newer) one runs much hotter and lacks the blue inter-electrode glow of the others. The tube has been tried in four different locations (V1 - V4) in my Rogue Atlas. The bias remains about the same as the other, matched quad tubes, so that's not my problem. An IR meter was used to measure a few different spots on the plate and the temps are consistent for seven of the two, matched-quad, sets.

The amp sounds fine, with nothing unusual heard on the channel with the hot tube. Most of the tubes indicate about 280 degrees F. with the one at almost 400F. The lack of glow around the grids is the only other difference from the other KTs. Thanks for any help.

For sale are:

• Class D Audio SDS-258 stereo balanced audio amplifier (gain is 29dB based upon 2K resistors, which are plugged in)
• ConnexElectronic SMPS500R
• ConnexElectronic Speaker protection circuit

Please PM.

A few years ago I made a set of these regulator boards for my own projects. I have 8 complete and working boards left. These are used in my projects so I know they work. They are loaded with top quality parts, e.g. Nichicon FW(M) capacitors.
They have a huge filter bank of 18800uF.
They are set to fixed 10V (soldered the jumpers as seen on photos) but can be altered.

If you wish, I can give you also the Eagle and Gerber files.

How about 120€ for the lot or 20€/pcs + shipping. Can be shipped anywhere.

Photos: TPSreg - Google Drive

I have 6 dual LM3886 modules as of writing this
$60 per module shipped US or best offer

With VZaichenko's help I've been working on a modular design full featured preamp with the design goal being a very good quality preamp DIY option for experienced builders. The initial design vision is to include single ended and balanced analog inputs, optical and coaxial SPDIF inputs, optional USB input, single ended and balanced output an optional headphone amp. I'm looking at optional FM tuners, Sirius/XM, Bluetooth ect. Control will be open source Arduino based with options for control over Bluetooth, RF, Wifi, IR (any format really). A 2U chassis is the target size for the whole project.

I have a couple prototype boards running so far. The analog design is almost complete. The input board has a couple errors and I need to add some more internal inputs, so it will see at least one more spin. Volume control is done with a PGA2310.

The output buffer board is working very well. It has an onboard Jung regulator designed by Ostripper to clean up the analog input supplies. The output buffers are one of Valery's current drive designs. It has RCA outputs as well as a THAT1646 differential converters for XLR out

The SPDIF selector board is designed to stack on top of the analog section. I have a first round SPDIF board operating, but I want to add extra inputs for I2S selections. This board also acts as a back-plane for the DACS. Mono PCM1794 DACs with output I-V converters and buffers designed by Valery will stack on this back-plane. These boards contain power supply pre-regulators and regulators locally for all their circuits as needed.

I've designed all digital controls to accept multiple voltages to allow for control from more modern 3.3V microcontrollers.

I have power supplies designed to fit in a separate chamber/Faraday cage to the side of the preamp. The analog supply is a simple unregulated supply with CRC design, the Jung regulator on the output board feeds all analog power to the rest of the preamp. The digital supplies is a lot more involved. It has a control transformer that powers all switching and controls with an onboard microcontroller controlling the analog supply and monitoring it's voltage. It has 12V, 5V and 3V3 outputs that are switched by onboard relays for any digital control needs. It also has a second unregulated supply for the DAC and SPDIF boards.

A lot of hours (and dollars) have already gone into this design and there are a lot more to go. I haven't done any formal measurements on anything yet, but the input and output buffers do a wonderful job, not adding anything or taking anything away from the sound. Output noise is under 25uV, so it's dead silent. Ostripper's Jung Regulator design is delivering wonderful clean DC with ripple well under 500uV from no load up to 1A+. The SPDIF switch is performing perfectly. The board outputs I2S signal to the DAC boards with no issues. DAC designs have had a few bumps but are coming along well now.

I am offering for sale within USA a pair of Emotiva PA-1 amps in excellent cosmetic and working condition. They have auto-power-on/off, run cool, and have a small form factor. The protective plastic is still in place on the display.

Asking $250ea with free shipping.

These amps use the well-regarded IcePower 300ASC modules. They are rated at:

• 140 watts RMS into 8 Ohms at 1 kHz at 1% THD
• 300 watts RMS into 4 Ohms at 1 kHz at 1% THD
• 450 watts RMS into 2.7 Ohms at 1 kHz at 1% THD

Manufacturer page:
https://emotiva.com/products/pa-1

I am Looking to buy , a piece, a pair or more, of Seas P18rnx/p woofers... i need them as backup for my current diy speakers..
If you have anything available, please let me know..

must be in great condition, and able to ship to Greece..
thanks in advance!

I was wondering if I should seal the box housing the 1 inch compression driver + horn in a much larger speaker. I understand sealing the midwoofer box is a given, but any benefit in sealing the horn as well? since the CD is already sealed I don't see why I should do it.
luc

I have pair of it and I want to maximize its power available on Pp Monoblock Pentode mode or Triode or Pentode SE......

Can I ask what Raa for PP pentode and Triode mode.
What maximun power can I get withn 800v 1nd 1kv?

SE Pentode Stereo...What Raa and max power at 800v and 1Kv?

I'm no designer and no good on load lines..please need you help

Thanks ....

I bought a smps with output of +30V and -28 v for use with LM 3875 Peter Daniel kit.
Is this imbalance acceptable and will it affect the DC offset at output?

Hi Guys,

I just received a sampling of LU1014Ds (my first ones) and I can't believe these are the real deal, I mean, how can something this small have a Pdiss of 69W? These are only slightly bigger than a TO-92. Are they really this small?

Too funny.

Thanks all.

This amp also is not producing +-16v regulated voltage and instead has +-2.5v. Rail voltage is +-40v. The regulated voltage is produced from rail through two pairs of 160ohm 5W parallel resistors. Mid-step I measure +-26v, but on the side which connects to all other components such as opamps, diodes, and the gambit I'm only getting the +-2.5v. Just after the 5w resistors theres a couple unknown diodes possibly 16v zener I guess.


It would appear that this amp may be muting by way of regulated voltage drop down but I am not 100% sure. Theres an optocoupler mid-board next to several diodes near the rail caps. No small transistors, diodes, and other tested components are coming up as concern. The amp was re-capped and aldo BurrBrown converted for the 2 OpAmps near the speaker terminals.

What holds the regulated voltage down in this amp?

Looking for one of the bigger minidsp, my 2x4 balanced is acting up. I already own a umik.

Open to a unit with dirac too. Thanks for looking!

Plastic is cracked
ribbons are destroyed
I was thinking of replacing the ribbon
But it has some fancy type multilayer ribbon material

Can anyone post the complete schematics for P-100 and maybe P-10 too?

Hi All, have an ADCOM GFA-5503 where I am getting some strange "motorboating" sounds randomly video here: Login to view embedded media .

I isolated it to one of the channel amplifier boards and figured to toss some new electrolytics in there, however to get to them I need to remove the board from the heatsink, but the MOSFET's are really stuck and not wanting to budge from the tape.

Anybody have any tips on how to do this? Am I going about this the wrong way?

Hello Everyone,

Sorry to post what may be something of an opinion-poll type thread. I have decided to build a Push-Pull amp based on either 6L6GCs or El34s. I was pretty much set on building the slightly reworked Mullard 5-20 presented on the Lundahl transformer site (see below).

But then I found a schematic for the Ampex 6516 (see below). This amp uses 807s in the output stage, but I think it could easily be adapted to 6L6GCs--if needs be. I used to own a pair of these in the late 80s/early 90s and have always regretted letting them go.

I am hoping for ~20-30 watts @ 8ohms. Any advice concerning these schematics? I am thinking that the first 5879 on the Ampex schematic could be left off and start the circuit at the 250ohm pot (or leave the pot off and start just after).

Whilst not a polymer breakdown .........my 405 transformer is putting out 69v so not good. I have this tx which fits in the case ok from a Yamaha amp 35v secondaries, could I use it to get the 405 up and running for a while?

Many monoblock power amplifiers have two heatsinks, one to each side. This appeals to me: it could allow either more total heatsink area or two lower-profile heatsinks (instead of one tall one), or some combination of both.

I can see how this would be valuable for class A, or a sensible choice for bridged stereo AB. But for a straight mono AB amplifier, two opposing heatsinks would presumably mean quite some distance between push and pull output devices or output pairs... and I've read threads where having even short fly-leads between the amp's PCB and output devices was said to compromise the performance (or stability).

So of course I'm wondering: would this be a valid concern, do special measures need to be taken, or am I misunderstanding something?

Thanks, Kev.

Just found this and would like to share.

No matter how far you push it ... there is always a guy going one step further ... 👍

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I use linux on my living room PC that's connected to my active speakers. For a long time I used DRC room correction with a set of hacky scripts based around pulseaudio and ffmpeg. I had hardcoded my DRC settings, my mic and output gain and my input and output devices so that I could recalibrate by SSHing into my living room PC and starting my script.

Recently pulseaudio has been replaced by pipewire and I replaced my sound card. My scripts have therefore become non-functional. After running all the steps needed to set up DRC manually from the command line - with mixed results ("aargh the mic gain is too low again!") - I think it is once again time for some automation, I'm just not sure how I should go about it this time. I'm looking for some best practices, ideas and inspiration.

My question to all the DRC users is: How do you capture and process your sweeps and generate your filters?

Hello everybody, today i want to discuss a certain case i encountered in my work that left me wondering where could the problem be.
I bought an amplifier "The T.amp ta 2400 mkx professional" with a broken right output hoping to fix it, i found the 8 output power transistors of the right side broken along with one of the two drivers "A145" slot to be specific, i replaced the broken Amiercan driver "ca1837" with a chinese alternative "2sa1837", and replaced the output power transistors with new ones, just for the same problem to occur.
Both the new driver and the new output power transistors were broken again.
So i replaced the driver again, and removed the output power transistors complitly, and the amplifier worked properly (the green led lights up and rolly works), but the problem still priciest when i put new ones (power transistors)on.
I tried testing and these are the numbers:
Emiter & base -/+70v
Collectors 0 gnd
These numbers are correct according to the datasheet.
So i ran out of theories and so I'm here to ask you. What could the problem be in this case?

MiniDSP Umik-1 measurement mic BNIB.

$60. Plus Shipping.

Hello hello,

This is my first post here after spending a few late nights on the forums and imagining my first speaker build. Apologies in advance for any errors of diyAudio etiquette. Let me know if I should be moving this thread to another forum!

I'm an audio/music fan (but far from an expert or audiophile), and I'm planning a speaker build with my brother who is an artist and furniture designer. We'd like to make a (hopefully) simple pair of single-driver/full-range loudspeakers. We'd like them to sound good, with a decent frequency response, but we don't need them to sound exceptional. Better than a little Sonos unit, I'd hope, but no need to compete with £5000 audiophile speakers. HOWEVER, we'd like to get quite creative with the aesthetic design. And I'm struggling to find much info on how specific aesthetically-motivated changes will affect sound, so I thought I'd stick my neck out and ask the diyAudio experts!

I have loads to read and learn, especially if not following a pre-existing build plan. But before we go further, I have two big questions which will affect our approach:

1. What are the important considerations when fixing additional material to the outside of a speaker cabinet? For example, could we build a tried and tested speaker, and then glue/screw another empty box on top of it in order to change the physical proportions for aesthetic reasons? Another example: could we glue/screw little details onto the side, top, or bottom of a cabinet, such as a small carved wooden sculpture?

2. Are there any limitations to veneer materials, assuming an mdf enclosure? In particular, we are interested in using a thin aluminium veneer, as well as burr walnut and white melamine (not all together!). It would be great to know if there are any 'no-go' materials for veneers?

For what it's worth, my current plan is to use the Mark Audio Alpair 10p, which seems to be well-regarded. Depending on answers to the above, I'm imagining we'll use one of the build plans on the Mark Audio website (e.g. https://www.markaudio.com/wp-content/uploads/2022/08/Despina-Alpair-10.3-10P-RTL.png OR http://wodendesign.com/downloads/simpleReflex-103-10p-plan-100214.pdf), at least to give us a basic structure. As a bonus question, I'm wondering to what extent we could change the positioning of the driver and port holes on tried and tested transmission line and vented designs, as long as the volumes and circumferences remained the same? E.g. putting the driver in the middle of the box rather than towards the top.

Thanks in advance for your patience, and for any help you're able to offer!

Lewis

I love experimenting with loudspeakers. The big bugaboo is always the crossover expense and having the required devices on hand to experiment. I want to try some type of electronic crossover. I have a number of amplifiers available.
Currently I have a MiniDSP. Very complicated to program and the unit I have sometimes causes distortion that is not tolerable.
Dayton 408DSP which looks like a much easier to use device ($220 with USB dongle).....or just go analog with a Behringer CX-3400 crossover (On sale right now for $126 shipped from Sweetwater)

Is anyone using either of these units? Comments?

Thanks

Hi everyone/anyone, I am new here and glad to have found a possible source for help. My speakers and the sub-woofer/control module all work fine! It says 2002 on the bottom so I guess I've had them since at least then. I loved them while they worked well, but when the small control pod began to malfunction I had to disconnect them. This would have been about two to three years after I got them. What happened was that the bass control on the pod began to cut sound off altogether when I tried adjusting. It also introduced a lot of noise when turned at all. Sound would cut out altogether, would get louder or softer and have a lot of static too. On occasions when I was able to finally get things adjusted to where they seemed to be just right, volume level would soon self adjust up or down or off, accompanied by static. I had to remove the speakers. Of course, by this time they were no longer being made/sold and I could fine no help anywhere. Searched the web on a whim recently and found this site and am hoping someone can help me get them up and running right again. I have no electrical skills, although I can wield a soldering iron as a result of working in stained glass for a few years. I have looked inside the pod and have no idea what to do. I have shot up the switches inside with Micro Care contact cleaner a couple of times but to no avail. I'd be glad to include some pics if they would be helpful. Sorry this is so long, but I didn't want to forget anything. Thanks in advance for any help/suggestions. Dunolde

Four 866A's all tested at 600v in a full wave setup, all tested at 230-250mA with a 2k load, see pics.

£20 each plus postage estimated at £3.50. Please don't comment on the subject of mercury/safety/posting of. Drop us a PM if interested, cheers, Andy.

I'm spitballing a plan for adding midrange taps to a B52/QSC clone waveguide using a Faital HF10AK, with Faital 12PR320 as the woofer, direct radiating.
This will be used for PA service. I'm already happy with the sound of this cabinet but I want to take it to the next level.

I have some Celestion TF0410MR and I'd like to use them. I've read many, many posts about this driver, but I am still undecided about whether I should be using 2 or 4 of them in this design.
No doubt 4X would be great but is it overkill? Fitting them on the horn will be a challenge but 2X looks to be much simpler, and of course less holes in this lovely sounding horn.
Then again, they are only 1mm Xmax and won't be seeing any horn loading at their low end. I'm imagining a 350-400Hz XO, 4th order.

Also I want to make a bare-bones passive XO for the mid/high transition to conserve amp and DSP resources. Would that be a fairly simple task for this particular setup? I sheepishly admit I've never built a passive crossover before...

I am building a thin 3-way 24x24" wallspeaker, and the backplate can only be 1/4" (6mm) thick. Only 1/4" MDF acts as a drum and resonates violently (even with some internal stiffening construction) at these large dimensions for low frequencies, so what material/construction should I use ? I even considered cork, rubber or vinyl.

Any ideas ?

I'm currently experimenting with bi-amping setups. I use the a/d/s/ 642ix automotive electronic crossover as an active crossover. It has a feature which allows the subwoofer signal to be fed to the main speakers when played in 2.0 stereo mode in lieu of 2.1, that is why I called it “pseudo-subwoofer”. The subwoofer signal is filtered at 100 Hz with a slope of 24 dB/octave. The issue is that the main speakers are playing in stereo, but the subwoofer signal can be selected between stereo and mono. Which one should be used?

I’m repairing a NAD M3 which requires a full recap. I’ve replaced pretty much all of the caps and came to the main filters, pulled out the filter caps I bought about 6 months ago and…. They don’t fit. I really should have paid more attention to the physical measurements.

The filter caps that are in the amp, which are all quite buldged, are snap-in and 40mm in diameter and 83mm in height. They are 22,000uF 80v. The caps I purchased are 27,000uF 80v and are 40mm in diameter, but 105mm in height. I’m so bummed.

I’m having trouble finding 40mm dia snap in caps that are 22,000uF (or higher). I could use the ones I have until I find some that are 80-90mm in height, but being at 105mm I won’t be able to put the top on the amp.

Anyone that might be able to find a good quality cap that will work, I would be eternally grateful. I’m stuck on this project until I find some and I have no choice, they have to be replaced.

Thank you,
Dan

Purchased new and installed in my Tacoma in early 2021 for PE; removed to sell the truck.
Simple-to-use unit I used to control 6 speakers plus a subwoofer. Tuned using REW.
Includes the DSP-BT4.0 USB device to connect via phone app. Some scratches on the case during installation under the driver's seat.
Decided to go with a different amp/dsp for my new vehicle.

$125 plus shipping.