Hey,

Got my hands on a Audison SR1D. Dont know the previous history but it came in with a blown psu section and someone had already tried to fix it with no results.
Psu had blown output fets and burned buffers. Since the pcb also had some damage i had to be a little innovative and used through hole pnp/npn for psu buffers. Got the psu up and running fine but output section was still faulty. I took off the IRS20124 and know the amp powers up fine. Output fets and buffers transistors all check out fine. Since theres chip shortage accross the world(atleast in the eu) i ordered 4pcs of IRS20124 from china. Now when i power up the amp im getting nice drive wave on the high side for the first 5 seconds, after that it goes silent. When i connect a load to the amp output to kick start it(10ohm resistor) the coils start whining and im getting a nasty signal on high side but still nothing on the low side, signal is there for around 10s seconds and after that goes silent again. Also the diode that feeds irs20124 with vcc gets really hot(was also burned out when the amp came in). The LM319M that feeds driver chip with pwm seems to works correctly and sends a nice small pwm signal that rides along close to negative rail to pin nr 1 of IRS20124. So pwm generation section with preamp seems to work well. Now only thing on my mind is that how possible is that i got fake IRS chips from china? I ordered 4pcs and all of them behave excactly the same. Or there is something that im missing here. Anyone else come across with similar problem?

I have gotten just about all the equipment needed for my home retirement lab. The last bit needed is a really good distortion analyzer. I understand the Audio Precision is the industry standard. Which would recommend? Considerations include not only robustness and distortion floor, but also the software interface and the interface between the instrument and the computer. We have a Sys 2 at work we use for audible noise measurements which seems to work OK, though the software interface is a PITA.

Hello all, it seems that most of the low noise, high gain through hole transistors are gone. The ones I like using when restoring old audio gear, like the 2SC2240BL and 2SA970BL. I of course use the KSC1845 and KSA992, but the available gain ratings are far lower.

I do keep on hand ZTX964B and ZTX795A devices, but I’ve read that while they are labeled low noise, they may not be as low as one would hope. Example being the 2SC945 and 2SA733 being lower noise. Would love to hear thoughts on the ZTX devices.

I’ve thought about going to SMT devices, I have a few hundred SMT adaptor/breakout boards and figured why not. Any suggestions as to what I should be looking at that would be a good replacement for the 2240 and 970? What about the 2SC2713-BL and 2SA1163-BL? Obviously they have lower power dissipation, but I’m looking to get as close as I can get.

Any other parts I should look at to replace long lost popular through hole parts?

Thank you,
Dan

Actually two of them and more to come.

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As a nubie to the realm of horns what are peoples opinions of the Lavoce DN10.142 it's response seems fairly benign (I'm not a bat so see no need of 15K+ hz) it's reasonably low cost and is presently available. So, what's not to like? If bad what's a better alternative?
Thanks for the advice.
https://en.toutlehautparleur.com/compression-driver-lavoce-dn10-142-8-ohm-1-0-inch.html

Interesting speaker that uses SB Acoustic drivers and Hypex DSP amps: https://6moons.com/audioreview_articles/noblenoble/

Starting here (#130)- https://www.diyaudio.com/community/threads/f-5-turbo-boards.233915/post-6960632
a member complained of no access one week, yet had access the next.. but nothing to do with the links was modified in that time or since 2013 when they were posted. Another member has just noted the same problem. I can access the files.

Hello
I’m selling this pass B1 bundle consisting of what’s shown in the pic.
Asking $109 shipped CONUS
Thanks for looking today

Hello, I have a BAT vk 150 stage and I am reviewing it and I want to change the electrolytic capacitors and I see that it is difficult to get them because they are so close to each other.
They are 270uf 400v 25x35mm and 1500uf 250v 35x40mm.
I would like you to help me find them.
Greetings

I would like to put a SOIC-8 IC into a board that has DIP-8 sockets. I can find the little adaptor PC boards, no problem. But I am having difficulty locating PINS to solder into the PC adaptor board that will then insert into the DIP-8 socket. Does anyone know where I can find these?

I am building a D1 stage but I dont know how I should biast it?
And any one have the service manual for it?
Attaching the schema..
I am going to use it with AD1862.

Hello! I have a pair of HiVi T20-8 tweeters I would like to use in a design, but I can't find any FRD/ZMA files or even CLIO files. Does anyone happen to have this information? Thanks!

Hello,
as the title suggest, can i use 5 watt zener diodes (reverse bias) to drop 100 or 150 volts for G2 supply?

I plan using 6550 tubes, g2 cannot exceed 450 volts, my B+ will be 500 VDC.

Many thanks

I thought multi chip NOS DACs were obsolete but here's a new one.
I can't find any reviews except in Russian, Google Translate isn't clear.



Looks like plenty of room for modding. You reckon it's got any potential?

I'm still looking for the chinese bargan.

New Release Finished L1543DAC 16X Sixteen Parallel TDA1543 HiFi Audio DAC

I'm cleaning out my place and I have an old box with diy gear that seems too good to throw away. Main value in there is two Soekris dam 1021 boards with Salas shunt regulators. The rest is a random assortment of parts. Shoot me a PM if you're interested. If there's a lot of interest I might try to charge a little bit for it, if not I'm giving it away as long as you cover shipping.

Hi all,
I have this cd player with issue like this:
IT starts up normally when loading it with cd. Then it reads TOC but when pressing play it spins up and laser moves step by step without playing anything. I assume laser is ok since it can read TOC very fast. I have opened it and found a loose part, see picture.
Could it be my cause to fault?
It sits in the lifting mechanism in front.
Thanks for any help in this matter.

This new diffuser??, is located behind the mid drivers of the new Borresen speakers.
Yet I've seen the same treatment by the new Yg acoustics Peaks series.
One design is ported the other is sealed.
... I'm confused...

Could someone explain the benefits of such a treatment?

Does anyone have a tip how to remove old hardened thermal paste? I was able to remove it from the heat sink with alcohol and PCB cleaner, but somehow this doesn't really work on the transistors.

*** November 9, 2013 - A new GB list has been started ***

Please see post #171 for an update.

If you are reading this thread for the first time, please DO visit at least the second link below. If you are interested in the boards, please post a one-line request. I have planned to make at least one small order in the next 2-3 weeks, so there does not have to be any minimum number of boards for a group buy, but it will be first-come-first-serve.

http://www.diyaudio.com/forums/power-supplies/51817-improving-capacitance-multiplier.html
http://www.diyaudio.com/forums/power-supplies/53359-finished-capacitance-multiplier.html

My thanks to Mr Evil for letting us use his thread to get the PCB off the ground and into production. The board in the pics below was designed from his schematic, with some minor modifications and options and for higher supply voltage than the original. My original goal was to use this PSU with Lazy Cat's VSSA as an alternative to switching supplies, and with through hole VSSA boards (see pics below).

The operating range is up to +/-50V output voltage, 5A peak current. The semiconductors and caps specified in the power supply are selected for up to 100W/channel, class A-B operation. This is not the maximum possible, but it is the limit for the components listed in the revision B BOM. The rectifier diodes and the large electrolytic capacitors should be selected for the intended use - there is no single formula that covers every possible application. Higher supply voltages require some component substitutions.

Key Features:

• Soft turn-on (to reduce amp turn-on thump and other audible noise)
• Adjustabe Dropout Voltage (for low and medium power applications)
• Higher efficiency than typical Capacitance Multiplier
• Lower noise than most Capacitance Multipliers (under 20mV, tested)
• Moderate component cost (under $25 plus cost of electrolytic caps)
• Capacity for 100 watt/channel Class A-B power amplifier

Documentation:

Schematic and BOM in PDF form are attached. Links to a Mouser BOM are below:

Key Components: https://www.mouser.com/ProjectManager/ProjectDetail.aspx?AccessID=2f2cddc696
Miscellaneous Components: https://www.mouser.com/ProjectManag...jectGUID=44bfeb06-a22a-4041-b761-bd9d71be3daf

I will post additional details and documentation as time allows, but there are already technical details and test results in the two threads referenced above. Posts specific to this board start here:

PCB discussion, testing, components, heatsinks, etc.

The PCB is in revision B. The boards are professionally fabricated, two layer, top and bottom solder mask, top silkscreen, plated holes.

Costs (Updated 22. August):

PCB, $10 each, plus shipping and Paypal fees.
Each board ships with two Jfets and two 3-mm LED's at no extra charge.

Typical cost incl. boards, padded envelope, shipping, and Paypal fee has been as follows:

US Domestic First Class, Large Envelope:

1 board: $13.50
2 boards: $23.75
3 boards: $34.50
4 boards: $45.25
6 boards: $66.75

Canada:

1 board $13.75
2 boards: $24.25
3 boards: $35.00
4 boards: $45.75
6 boards: $67.00

Europe and International:

1 board: $14.25
2 boards: $25.50
3 boards: $37.75
4 boards: $49.00
6 boards: $71.75

If requesting shipping via USPS International Parcel as merchandise, with customs declaration (and a very official looking label), please plan to add $6.50 to the cost above. In all other cases, boards are shipped by regular mail.

Hello:
I've been bothering you a lot the last few days. Sorry 🙏.
I finally settled on the Dallas II build for my Fostex FE206NVs. I would like to simulate Dallas II at Hornresp. Does anyone have the exact values? S1, S2, exp, etc?
Thank you very much.
Christian

A while back I got interested in the 6N6G tubes because they contain a direct-coupled driver and output stage within the bottle. The ~4 watts output is perfect for my efficient full range driver speakers. They don't need much gain on the input, so I decided to start with a type 27 indirectly heated triode before moving on to direct-heated type 30 and 26 triodes. FlaCharlie has been working with this tube as well, so some of my experiments will likely be close to his.

Here is a schematic of the first trial circuit that I've breadboarded. The 27s and 6N6Gs are AC-heated, all in parallel, using 0.56R/25W dropping resistors downstream of the 6N6Gs to get 2.5V for the 27s.

The 27s are currently running at about 172Vp, 11.5Vk, or ~160Vpk @ 5.75mA.

Rectifier is actually a 5R4GY.

The B+ is about 323V. For the 6N6Gs, after the OPTs there's about 315V on the output triode plate and about 305V on the input plate. There's supposed to be 300V on both triode plates, at least as I understand the datasheet, so I'll need to tweak that a bit. Unless that's supposed to be 300Vak as for a normal tube, but there's no way to get the cathode voltage because the resistor is inside the bottle. Either way, it is within the maximum operating point of the tube.

The OPTs are a bit odd: Tektron 3.5K with 6R and 10R secondaries. With my 15 ohm Lowthers on the 6R winding, that makes a reflected load impedance of 8.75K to the output triode plate. I've also connected the 10R secondary to a headphone jack, which with my 32 ohm cans will reflect a 11.2K load impedance to the output triode plate; I haven't listened to the headphones yet.

On speakers (Lowther PM6A in trapezoidal Onken, no filter), this version sounds like a typical SET amplifier; lots of detail and a lovely midrange, though on some recordings it can sound a bit strident. I did not put a cathode bypass cap on the 27 because I didn't need the gain. With the 100K volume pot turned up all the way and using Pandora on an old iPhone as source, it gets to the cusp of what I would consider uncomfortably loud. But the whole range of the pot is useful, which is nice.

I will also be experimenting with bypass caps for more gain and maybe even something like 6J5 or 6SN7 on input (maybe even as low gain cathode follower).

I've been given 2 humming dual 300B SE amps to fix. They are 2 of 4 identical units from a 2-way system.

I've attached my reverse-engineered schematic. The first stage appears to be a SRPP amplifier.

That's OK. But why the need for an inter-stage transformer? Why can't the blocking capacitor following the input stage feed directly to the grids of the parallel 6H8C/6SL7GT triodes?

You can see from the picture of the inside of the chassis, that the builder appears to have used an earth follows signal earth bus. Could be multi-stranded silver wire. It's just floating, or hanging when the chassis is the right way up. Very odd. Those I've seen before are a large solid core wire hard mounted on insulators. A lot of the solder joints on the earth bus look dodgy so I'll start there.

after about 150hrs break in they are now outstanding, very smooth and detailed bass, imaging is superb, vocals and instruments are spot on, depth of sound stage is excellent

Hi,
I am assembling my tone control module with bypass but have some doubts. Please see attached picture. I am using Latching push switch having six terminals. The stereo input signal from source will be on center pins when pushed the input signals will go directly to output. When in other posisiton the input will go to bottom pins > to tonearm module to > Output which will be connected to same pins as shown.

my questions is
When in position 2 Input goes straight to the output BUT it also has tone control output wires conneced (however input connection on tone control board will be OPEN )

Will that work ?
Because in reality when in bypass mode I will not only be supplying direct signal to output but also to out put of tonecontrol board. As shown in pic no. 2
Tonecontrol board will have power on contineously.



Thanks

Looking for a 230/240v primary, 2 x 18v secondary, 500va toroidal transformer, preferably in the UK

Using The Slide Rule In Electronic Technology


https://www.sliderulemuseum.com/Man...uleInElectronicTechnology_ECharlesAlvarez.pdf
24MB PDF

Dear all, I bought a board that is equipped with the aforementioned processor, but unfortunately, the sample rate is factory set at 96K. Since I have to load FIR filters into it, I would like to set the sample rate to 48K which would help me to use more TAPS. The fact is that changing the sample rate on these processors is not possible by software using for example sigmastudio, but the chip with embedded crosscore must be flashed directly, which unfortunately I cannot do. So I need someone who knows how to do it and who will help me with a step-by-step guide or in any other way. Thanks in advance to those who want to help me, I really need it. Greetings to everyone

The clear out continues.....I have have a very nice Nelson Pass (First Watt) F6 amp built into a DiyAudio 5U deluxe case.

The only thing you would need to complete is a 500vA transformer with 2 x 0-18v secondaries.

I have powered it up on the bench PSU and its working as it should:- bias is set to 0.6xx mV per channel with the offset less than 10mV.

It is a large chassis and by default with a Class A amp runs hot 45c - 50c

The chassis came from HiFi2000 via DIYaudio shop as did all the components inc the PSU, so all the jfets and are mosfets are matched.



right channel as we look at it.





left channel as we look at it.



As a bonus it also comes with a full set of F5turbo boards (without mosfets but inc the diodes) which you you would need to source then you can swap the F6 boards for these if you so wished. It runs of the same PSU 25vDC.



There is a load of info of over at DIYaudio and you would need some DIY skills to complete.

£500 the lot.

Cash on collection (Hampshire UK) I can ship but because of the weight 'would cost quite a bit'.

Hello everybody,

I try to find genuine AD1865 chips, but unsuccessful.
In Ebay only fakes. One remaining oportunity is Rochester. Prices are high, but there no more chanses to find genuine product elsewhere. Minimum order price is 250$ + 48$ shipping, that means minimum order quantity is 6 pcs of AD1865. I need only 2 pcs. If anyone want colaborate with me, please send me PM or email: tadas.dadurka@gmail.com

link: Analog Devices AD1865N-K

Best regards.

Hi, I want to build subwoofer amp using TDA7294 bridge application. My probem is that in datasheet is +-25V for 8 ohm load but is it voltage of transformer or voltage after rectification? Because now i dont know if i need to buy 18-0-18 trafo or 25-0-25 trafo. Thanks for help and sorry for my english.

Hello folks,
There are gazzilions of chipamp queries, adding some more. I recently built a chipamp and they sound good. I also took Pano's wonderful Speaker voltage tests. (LINK)

in my small room and I got 1V at speaker terminals for normal listening level. 2 to 3 V at maximum volume level. Nothing else to do and fooling around I measured current draw at Transformer secondary wire. Shown in Red Dots in attached picture. Results were.

At 1v on speaker Terminal = 66mA current
At 2v on speaker Terminal = 100mA current
At 3v on speaker Terminal = 140mA current
At 4v on speaker Terminal = 184mA current

So I will presume that even at 4 times the the volume level I listen I get around roughly 200mA. For Centertapped Dual +/-Ve supply I will presume current draw is aound 0.5A.

my questions are...
1) How low amperage rectifing diodes I can use safely ? Pease give few names.
2) The amp has separate PS Boards and transformers for each channel. I have few capacitors of 1000uf, 2200 uf and 4700uf and of suffecient voltages lying around. Will that be ok if used as shown in the picture ? I suppose having lower or higher value capacitance near amp board doesn't matter. Or Do they ?
3) My transformer wires (length of about 6 inches) coming out of secondary winding coil seems thin. If I cut them close to secondary winding and replace them with thick wires. Would that be of having any advantage ?
4) with Safety and probable future scenario in mind and given my current draw. What value fuses should I use and where ? My transformer is 18-0-18v. Basically I want fuses to blow if amp is driven hard or some mishap occures.
Thanks and regards.

My Jeff Rowland Model One is stuck in stand-by mode. Pushing the front button nothing happens (*).
Any suggestions to fix this issue?
I would also appreciate any suggestions for disassembling the unit, as this does not seems so easy.
Thank you very much.

(*) In a working unit, pushing the front button causes the passage to operating mode, and you can hear the click of a relay and see the indicator bulb increase in brightness

Synergized of course

Hey all. I have a 2011 Audi C6 A6 3.0T that i'm trying to find a good Aux Bluetooth Receiver to be able to play my own music from my phone in the car.
I've got an AMI MMI to 3.5mm Aux cable to plug into a bluetooth receiver, but i'm having a tough time trying to pick a decent receiver that has good sound quality.
I've already bought a the AUKEY BR-C8 because I saw it recommended on a list, but it doesn't seem to be the best quality. Treble seems to be too high on some songs, while others the songs seem to distort at even a slightly higher volume.
I've done a little research and came across "Hi-Fi", "DAC & aptX" receivers that are a lot more expensive, but i'm not even sure if these are up to the hype as reviews tend to be mixed.
Can anyone give any recommendations on good bluetooth receivers or explain what makes a good one and what to look out for?

I stopped by the local granite countertop place on the way back from dropping the kid off at college with his bicycle. Remnant madness sale the sign said. I purchased a pair of 12X12X1" finished blocks in white for $20. I'll do something with them...

Anyway they sell / install kitchen flooring as well. They had display panels the manufacturer had made up; looked like about 18" squares with 1/4" masonite backing the flooring surface, with 1/16" of some yellow colored stuff in between. Balancing it in the center on my finger, I gave it a tap; nothing. Quite dead. I wanted to bring a pair of those home too, but didnt ask...

Anyway, something to keep in mind. I wonder what the yellow stuff is?

Bàn xoay LP với 3 động cơ
Www.teela-audiophile.com

www.teela-audiophile.com

I have a 3 way speaker sitting on the sidelines and the mid and tweeter are on sleds so that I can individually position fore/aft. I have Omni Mic and DATS measurement tools. Is there a way I can align and make meaningful measurements with the tools I have? Im trying to learn about this and was thinking how does a manufacturer do it? Can I do something (even basic) to test this?

I had 10 Ship of Thesus Nimitz FE PCB's made for my Sony 2SK60 VFET amp build. Nimitz uses the daughter cards from the M2x project. I'm using only 2, so I have 4 pairs to sell. $5 a pair plus $5 shipping via USPS padded envelope, payment by PayPal Friends & Family only. PM me to purchase.

4x-150a Single end - YouTube

4x-150a single end Prototype - YouTube

I am researching drivers and I notice that SB woofers cost considerably more than a Peerless Tymphany woofer. Are the SB generally better drivers? I know the Sb are not made in Denmark so I would think their prices would be in line with Peerless. (At least they are cheaper than Scan Speak Lol)

Hello. I learned to use the Hornsteps. It's not hard and I simulate the Horns that I found for the Fostex FE206NV. There is very little information on the NV as it is relatively new. All the information there is for the Fostex FE206EN. I share the simulations and the Horns.

I’ve been wondering what other makes and models of PA speakers that uses the TAD 4002 compression drivers and 1601 woofer? I’m assuming other companies used TAD gear in the speakers

I tought quite efficient vented 12" subwoofer. I would use about 50-100W amp (AV-receiver zone2). I found SB34NRXL75-8 driver. 80 liters enclosure would make possible to use reasonable length 100mm diameter tube at about 20-25Hz tune. Looks like there is not many drivers like this. Is it so or should I search better?

Since the new software rollout I'm not receiving notifications anymore. Do we have to resubscribe?

As new, only few months 160 euro shipping in europe as i'm based in Italy.

Hi guys!!

Our new job! Amplifier for professionals (music mixing and sound studio)Very accurate measurements, the sound of the amplifier does not add color, everything sounds like in the original.Almost complete absence of the 2nd harmonic. It is possible to manufacture an amplifier 1000!!!! wat
by increasing the number of output transistors!I Сan remove feedback! The sound will be familiar to the common man but not true
In this case, the bet on sound quality! Quiescent current of output transistors 200mA. Lifetime warranty for first customers.Production is possible XLR input.

https://kdsdostup.wixsite.com/sarts/aplifier-sas

Hello,

Several years ago I acquired an LXmini variation made by Beanstalk Audio (mentioned about 1/4 way down this page). I am the second owner. They worked perfectly for a few years in a family member's system, and then were put in storage for at least a year. I am now wanting to use them in my own system but when I hooked everything up there was no audio coming out of the miniDSP 2x4HD. I have set them up successfully a few times in the past and I confirmed that all other parts of the signal path were working correctly.

While unsuccessfully trying to get music, I did poke the reset/control button a few times. I don't know what this did, as it's not drawn or described in the user manual, and is only labeled on the PCB drawing.

I've now downloaded the $10 plugin for the device but my macbook isn't seeing it to connect and I can't locate anywhere to download the config files for the LXmini. I also don't know how different the Beanstalk config would be to the stock LXmini.

Does anyone know what's going on with the miniDSP? I suppose it could have just gotten damaged somehow in storage. Any suggestions for the quickest way to use these speakers without too much monetary investment? Also, does anyone know how to contact Ben from Beanstalk/Ono? I had an email and phone number from 2016, but neither worked.

Hi all,
Some drivers I have are in a bit of trouble. The surround which is stuck to the cone is beginning to come off. What kind of glue should I use to stick it? Will a synthetic rubber based adhesive do or should it be the Loctite super glue kind of thing?

Thanks and regards,
Vivek

I have a really old device and I can only access the speaker wires of it. I want to setup a line level from the speaker so I can connect it to another device.

I used a very simple voltage divider (2 resistor like the image below) to bring down the voltage from the speaker to line level (close to 1v) - as many people suggest online. It works fine, however there is a noise/huming that bothers me when I connect this line level to another speaker (using pre amp). It's not very loud, but when there is no song playing it is very distracting.

Reading online, it appears that using cheap resistors to bring the voltage down may create lots of noise. So what do you recommend I should do? Is there any "non cheap" resistor which is "audio grade" so I can use it to make this voltage divider?

NOTE: in the old device's speaker, the sound is perfect, absolutelly no noise. So the sound coming from the speaker is clear of audible noise.

Hi

I have recently acquired a TacT MK2 Millennium Amplifier.

Unfortunately, it's a missing the remote control and I would really like to utilise the "max volume" and "display dim" features. There is no menu system to set this using the fascia buttons. I have a Lyngdorf branded multi remote, and unfortunately it does not control it.

It's a very old model now, so the chances of finding one second hand are slim... The max volume feature is of particular importance to me as it stops (little) people turning it up too loud if they play with the free spinning wheel. It's saved my speakers from excess volume / damage many a times when using a Lyngdorf model with this feature.

Are any former/current owners out there able to assist? I have a programmable IR blaster to hand, or failing that perhaps utilising the on board RS232 interface a possibility?

Thanks very much,

Dawson

Hello all,
First time here, but not new to the audio world. I have extensive experience with the 12-volt industry and mobile audio. I have made several bookshelf speakers in the past that sounded good. The standard tweeter on top and a mid-woofer right below set up seem to be the norm. But now I want something different. I was thinking about a cube design with the mid-woofer firing up and the tweeter firing at the listener. Will this design work?
I am using 1inch titanium dome tweeter; Crossover 3500Hz 12dB/octave
4 inch midbass woofer: Crossover 800-5000Hz 6dB/octave
All parts are from Dayton Audio.
Thanks for youe time.
Tom

Hi guys,

First of all, some info on this well-received driver. I have read over Zaph's Silver Flute design but wonder if there's a cheaper tweeter that mates well with it. As for the crossover, I want something simpler but adequate...how about a 1st order Butterworth?

Comments are appreciated.

Does anyone know what power supply fets and outputs this amp uses ?

As you can see someone tried repairing it before and put outputs in the power supply section .

So I’m not even sure if the outputs that are in the amp are correct .

What happens if I put a speaker of Fs: 45hrz in a horn tuned to 37 hrz? Am I going to have a problem? The horn must have the length of the wavelength of the Fs/4?

Thanks
Christian

Hi All!

My late 44 (s/n 034981) is hooked up through a 405.2 to a pair of cheap 4 Ohm speakers and I am having difficulty replicating the occasional sharp crack that I was getting more regularly through my Spendor LS3/5a speakers.

The 44 was last serviced by Quad in 1995. I carried out the 'Erratic input switching' mod and mistakenly used a 47uf cap instead of a 4.7uf cap. Later after use it stopped completely, and it is now working again after replacing the relay and blown zeners 404/5 and the 47uf switching mod cap.

I have been using the 405.2 regularly with a 33 and have had no trouble with it.

2 hours and not a crack in sight. Does any one have any idea what it may be. I want to sell them but don't have the confidence while I have this issue.

Many thanks
Enthusiastic and an amatuer

Good day. Can anyone help me please if you all have any info on what driver chip this amp carries. I have repaired these amps already, but only Powersupply section. One of the chip is dead and both are defaced as usual with SD amps, Board markings under the chip is FAN7xxx but im not finding any FAN soic 16pin chip that matches the pinouts. Any help is very much appreciated.

Pinouts:
4: COM
9: COM
10: LO
11: VCC
12: NC
13: NC
14: VS
15: HO
16: VB

Hello folks,

Does anyone have any experience in comparison between the Frugel-Horn Mk3 for Mark Audio Series 7 and the Lotus – Double Mouth MBVR for Mark Audio CHR-70 by Wooden Design/ Scott Lindgren regarding LF performance? Thank you very much!

Greetings Steve

I am looking for the setup numbers to test these tubes on my Hickock 6000 tester.

Hi,

I have an ATC PA75-314 Castle, it was a custom model for a Castle Acoustics subwoofer, it had a mis-aligned coil and has been re-coned by ATC in the past year.


Castle / ATC Subwoofer by Robert Seymour, on Flickr

Its in a ~35 Litre sealed cabinet, so I assume a big dose of EQ built into the plate amp. We are moving house, with a larger room, around 16ft square I was thinking of improving the sub from the basic sealed cabinet to maybe something built to go in the corner of the room.

With the specs below (direct measurement of the driver), with such a low Qts, could a horn/tapped horn be a good option?

Hello everybody.

I would like to build an Orange Crush 35RT clone. Well... in 35RT, 'R' stands for Reverb and 'T' for Tuner and I don't care much for those features, so let's say I want to build an Orange Crush 35 clone 😉

Yet, there is no way to find a schematic of this amp. I have found its little brother's schematic (CR20L) but I would like a little more power, and I am interested in an FX loop.

Since there is no schematic, and as I should be able to redraw a schematic from good quality pictures, I was wondering if anyone had those kind of "inside the beast" pics. Of course, if I find these kind of pics and draw a schematic from them, I would share it 😎

Can anyone help me ?

Thanks in advance!

Hello

I was wondering whether it would be possible to build a dual tl design.

I want to place 2 subs in the same tl design enclosure, in order to safe space and costs (yes, i know wood isn't that expensive, but i'm just cheap).

I went online and searched for hours, but i couldn't find anyone who had the same idea. But my dilemma is this: If i place 2 subs in the same tl, would the mouth then have to be the size of the area of both subs together, or would it have to the same size as if i was just using 1 sub?

Keep in mind that i'm not looking to make it tapered, nor push-push or push-pull. I want to mount both subs on the front baffle, right next to each other. This might not be be very efficient, which is why i would love to get some input as an newbie in the audio world.

- Sebastian A. (from Denmark)

So I'm trying to work through various builds, with a specific size requirements (need 12" wide, and tall enough to use as stands). This is my first sub build.

I prefer a tight bass. I plan on using it for mostly music and tv, with the odd movie thrown in. I don't need earth shattering 20hz thx level bass.

Right now I'm modeling the Dayton RSS265HF-4. I want to go sealed but I worry that it wont be sufficient in my moderately sized living room. I want to build the sub so that I can stuff a sock in the inside or outside opening of the port to go sealed, but have to option to run ported as well. This will be my only chance at building a box, as I will no longer have access to a shop in a few months.

Gonna use a minidsp 2x4hd and Crown XLS 1502.

PORTED
2 cu ft gross enclosure
3" x 20" port, tuned to 22hz
1.6cu ft net (port/driver volume)
Cone excursion and port velocity will require a filter -4db filter @20hz
After filter - Expected f3 28hz f6 23hz

SEALED
Sock on the outside: 1.85cu ft
QTC: 0.656 - 38.68 Fsc
F3 42hz
F6 31hz

Sock in the inside: 1.6cu ft
QTC: 0.680 - 46hz Fsc
F3 42hz
F6 31hz

1. Is a stupid idea?

2. I can't decide between the Dayton RSS265HF-4 or CSS SDX10, they model very similarly. The dayton has a little more sealed SPL, but the CSS has more excursion head room. The CSS also has 4m/s higher port velocity with a 3" x 15" port tuned to 26hz. The spl between the 2 drivers track identically in WINISD. I don't know which driver to pick 🙁

Thanks!!!

Добрый день всем. Представляю вашему вниманию серию межблочных кабелей "Призрак". Разработанная мной конструкция кабеля, минимизирующая его емкость и индуктивность, выполнена одножильной. Поэтому его влияние на путь минимально. Выбран наиболее удачный дизайн разъемов rca. Центральный штифт полый и изготовлен из меди. (так говорит производитель). На данный момент в серии 6 видов кабеля. 1. Оба проводника изготовлены из меди Клотц высокой чистоты. 2. Центральный проводник – монокристалл меди с серебряным покрытием. Заземлитель-медь. 3. Оба проводника выполнены из монокристаллической меди с серебряным покрытием. Есть два варианта разъемов rca. С золотым и серебряным покрытием. Другие варианты разъемов доступны по запросу. Стоимость продукта. 1 вариант. 58 долларов США. Вариант 2. 67 долларов США. 3 вариант. 79 долларов США. Наличие необходимо подтвердить. При отсутствии нужной опции срок изготовления до 3-х недель. Все кабели ручной работы. Используется серебряный припой с медью. Дает вам лучший звук.

Hi, I'm debating putting a small subwoofer - SVS 3000 micro in a piece of bespoke furniture

There are 3 options:

1/ Have the sub stand on the ground, furniture really only standing 'over' it:

It's a 2-way side firing sub, so two holes with grille cloth on the sides

2/ Have the sub near the ceiling like so, but standing on the furniture


3/ (crazy?) - suspend sub from my concrete block ceiling in a 'tray' and build the furniture around it, without touching

Apologies for terrible drawing but you get the idea perhaps, sub=red, non-touching furniture=green, tray(+ceiling) = black

My key question- will a sub standing in/on the furniture (option 2) will be terrible if the furniture is primarily holding clothes (shoes for outside) and books? Nothing that will really "rattle" like glassware or whatnot.

Hello
Attached are two documents. The first one is information on my experience repairing a Hafler 9505 amplifier and the second is a schematic.
Hopefully this information will help someone fix their amplifier
Engineer Ben

Upgraded from the CX 32400 I'm using 4 old passive 12s as my bass units but in smallish [ 36l] sealed boxes now and I'm wondering if I really need a block at 20Hz.
It's a rehash of my old stereo system but with the new XO unit.
Bass/Mid-Bass/Tops with no change to the drivers or the simple XO on the Vifa silk dome tweeter
They are cheap drivers in cheap boxes while saving [ still saving] for a pair of decent 15 or 18inch subs

hey Guys

Has anyone here any experience with the Hafler 9505? I got ahold of one for basically free and it's has a rather obnoxious turn off thump. I'm wired directly to sixteen 12 inch woofers in an all-active system and the thump is a bit like a shotgun going off due to the high sensitivity of everything. Even if I'm ready for it, it's a shocker. 😀

Anyway, I've had thump issues with other high current amps (B&K in particular) so it's not like a big surprise, but it's been with passive speakers witth sub-90db sensitivities. I went ahead and tried something to see if I could at least dampen it and added 1600uf caps in series with the driver arrays. The large uf was just to get below the driver rolloffs (4ohms at ~40hz) and it helped - it now sounds like a .22 at 30 feet. 😀

Here's what's interesting though. When I watch the drivers at power down, they move inward first now with the caps in the signal path and then seem to oscillate for a split second. Without the caps, they just move outward with a healthy bang. Is it possible to have some kind of negative DC going on here? I'm pretty much electrically illiterate, so my understanding of what's happening here is minimal.

Any thoughts? Anyone else with Hafler 9505 amps having turn off thumps? Should I have it serviced?

Thanks.

Hello,
based on an overview from an old forum thread, that is:

https://www.diyaudio.com/community/threads/tube-buffer-preamp-design.326689/

I was wondering if a schematic from the first picture I attached here would be a good choice for a low gain line preamp (or to call it "pseudo-buffer").
This arises from the need that a large gain is not needed and something like 6dB may be sufficient. Of course, since the two stages together amplify by 12 times globally, it is necessary, for example, a resistive divider at the input that attenuates the signal.

I took this simple circuit from audioxpress as a reference for the thing, adapting it to my tubes and operating characteristics.

https://audioxpress.com/article/you-can-diy-repurposing-an-old-preamp-for-line-level-duty

If there is any opinion about it ... thank you

Hello!

I've been playing around with R-2R attenuator board for my diy system. The attenuator will be controlled by the Arduino. The attached schematic is fairly standard. I have sketched two possibilities: with through hole and SMD resistors. I have not decided yet which way to go but am more inclined towards SMD version. I also decided to wire the relay coils off board via the pinheads. I've tried to follow the signal while routing the PCB but may have overlooked something. I am new to the PCB design.

Could some of the gurus advise me if either side of the PCB (through hole or SMD) have problems? Any input is highly appreciated!

OlegSh

Hi guys,

I got an ICE Power 1000ASP module all hooked up and running but I do not understand how to connect a 3.5mm 12volt trigger to it. I’m trying to get the amplifier to go into a standby mode triggered by my HT Pre.

The ICE Power modules already have this feature implemented however I cannot understand how to connect the 3.5mm 12volt trigger to it.

I have attached a diagram from the B&O manual of how the 12volt trigger is supposed to be connected to the module, could someone please translate it to me into lamers terms and help me get it working.

Your help is very much appreciated, thank you.

Hey guys
I'm being offered these tubes.
Any ideas if any would be useful for audio?

1x2b
1s2a
1AD2
1S2A
1RK231S2
2GK5
3ej7
2gk5
3AU6
3dk6
3cb6
3d-hh13
3d-hh12
4Mp12
4rhh2
4M-P12
4r-hh2
5m-hh3
5MK9
5r-ddh1
5aq5
6aw8
6aw8a
6dw4b
6bn8 (x2)
6rk19
6ehh8/6kn8
6ej7
6rhh2
6dk6
6Tuba
6al5
6mhh3
6ej7
6bx6
6bz6
6r-b11
6cs7 (x2)
6rhh15
6mhh3
6cb6
6UB
6R-HH15
6M-Hh3
6AR5
6AW8A
6AQ5
6AB8
6AV6
6BA6
60G8
6AB8
6GY6
7m-p18
7HGB
7DJ8
7DJ8
8B8
9r-a11
9aq8
10cw5
10d7m-p18e7
12gk17
12gk17 470
12bb14
12gk17
12BH7A
16A8 (x3)
18gv8
26k5

Click to expand...

Click to expand...

Hello to everyone,

I have a simple question: Can I replace NEC UPC4570 with OPA1642 at DAC output?

My new toy MiniDisc recorder deck SONY MDS-JE640 will get all new audio caps instead of JAMICON... so that's fun!

I removed yesterday all NEC UPC4570, original circuit from service manual shows M5218 opamps (Mitsubishi Electric), see page 41, components IC160 and IC260.
Service manual in pdf is here.

I think I could use OPA1642 also for IC390 as headphones opamp and IC350 as analog input opamp. Any thoughts about my plan please? 🙂

I appreciate your opinions, thank you very much!

Best wishes, Milan

New to fourm not new to car audio though I'd get some opinions an possibly some advice here. I bought a really nice dd zse that had let the magic smoke out and allot. I'd say more half the fet's on the power supply side self destructed and almost as Manny on the audio side my plan is to replace all of them so I have allready removed all the MOSFETs surprisingly the board and all the traces survived in great shape.both several gate resistors on the power suply burnt to a Crisp so I might as well replace them while I'm at it. Rightnow I am in the middle of sourcing 24 - IRFP064N power suply fet's and 24 FDA 24N40F MOSFETs for the audio side I usually buy component's from digikey but they want 9$ a piece for the irfp064N and even more for the audio side fet's so my questions are would it be smart to find compatible cheaper more avalible mosfet or if anyone knows a better more affordable place to order these components finally if I can't find anny more affordable MOSFETs is this amp worth me paying about 500$ just for fet's then probably more on the driver ic's resistors ext anny input appreciated

Hello all,
I often read that ESL efficiency is inversely proportional to the SQUARE of the distance between stators. How come? the ESL is effectively a plate capacitor (?), where the field strength equals V/d (Voltage difference between stators divided by the distance between them), and not V/d^2.
Looking forward to your (well reasoned) replies.

2x JRC MUSES01 OP AMPS
bought from Mouser


40€ + shipping

SOLD

Depeche Mode keyboardist Andy Fletcher has passed away.

https://www.bbc.com/news/entertainment-arts-61597992

RIP Andy Fletcher.

Hi

So I just disoldered 2 capacitors from my tube amplifier. I think I made a bit a mess, there is still solder residue on the copper traces of the PCB. The pump doesn't remove it.

Is there some trick?

Can I just solder the new capacitor anyway for the time being or?

Just read that Alan White of Yes has passed away. You were great Alan. Rest In Peace.

https://www.bbc.com/news/uk-england-tyne-61600583