I bought one of these SMSL M300 dacs, and it came with a split dac cable
(one side for power and the other for data).

Now, what's the point of that if you're going to plug both ends in a PC? lol.

Hi All,
We've been cooped up in our house here for weeks due to the covid-19 thing so I figured it was time to do something about some old speaker cabinets I have. After doing some initial internet research, I've come to the conclusion that the only way I'm going to get satisfactory results is with a little help before I jump in.

Please take pity on this noob and thanks in advance for any direction you can provide.

At last! I tamed the beast! After a lot of effort, troubleshooting and back and forth got it to work. It turns out that the main issue, I believe, was that I had not installed R23 and C4 in the circuit, which apparently that option is for the big output transistors. Maybe cleaning all the flux, going over a few suspect connections and rewiring everything, had an effect also. With my FW F4, it was working perfectly right nevertheless without any anomalies whatsoever. There is a big 220uf cap in its input circuit, so I guess it has to do with it working.

With my Pass XA25 it turns out that it was responding in its protection mode. This is apparent because it responds with very low gain and does not get hot. It turns out that after installing R23 and C4 the offset output had gone up to almost 1v. Dialed these down to “0” v and everything was ok.

The LS even without break-in sounds very refined, smooth, transparent as hell, soundstage is huge and all the instruments are very palpable. Gain is a little less than with the ba-3, where my attenuator position was usually at the 9-10 o’clock now it is at 11-12. Even with the F4 its position for equivalent output volume is at the 2-3 o'clock position.

But the big surprise was its synergy with the F4. If you want to know how this linestage really sings you have to listen to it thru the First Watt F4. It is really that good, both are that good, a revelation. There is an effortlessness quality that is very special and musical. It does not have the punch and dynamics of the XA but its presentation is kind of delicate or I could say ethereal. I hope that the tribulations addressed above help future builders. Thanks to Wayne for this outstanding design, and I wonder how it would compare with a PL XP-12.

hi everybody,
i do some FR test on my 2425h (with horn) and i found that it fall about 5KHz.(see pic)
the measure taken from listening position (not 1m from the horn)
i looking for super tweeter for about 80$.
i buy the fostex ft17, but it start to rise from 5KHz, so its not fit.
i interesting in something like jbl 2405 (but chip). the directivity issue interesting me.
i found the Selenium St320, but only one pice.
Beyma CP21 is little expensive.
Would appreciate help in finding tweeter that suits me.
thanks

Hello everybody
I have an idea like this.

By giving a single button pulse with a cmos ring counter (cd4017). Do I have problems if I make the input selector by applying a relay with the transistor at the output?

If I combine the sample schemes for the counter and the relay stage, if I do this with double contact relays and use the chassis of all inputs, does the loop, etc., do any of those have done before?


As the third stage, how do you think if I combine a digital volume control integrated with the volume of 2 buttons and mute and gather on a single board?

Hello everyone,


I have found this paper by TI http://www.tij.co.jp/jp/lit/an/slyt299/slyt299.pdf and designed an active crossover in this way.
It gives a linear phase response and avoids coupling capacitors. I prefer DC coupled designs and avoid coupling capacitors whenever I can. For compensating the low frequency loss in open baffle or dipole speakers I have added a low freq. boost. It can also be useful with closed subwoofers.
I use 2 of these crossovers in my active speakers one for dipole bass F.A.S.T and the other one in my studio monitors and I'm very pleased by the results.

Hi, have a pair of Eikona 2 drivers slightly used over 2 years. What should be a fair value to ask for selling?
Have no reference, sincerely.

First the usual amateur, stupid question, etc. apology.
Then the question - and if there isn´t a fixed rule, if it´s topology dependent or otherwise, than this pertains push pull tube amps. So I´ve built two, el84 push pull triode strapped no feedback amps. And on both I have connected the speaker minus to the star grounding point which is then grounded to the chassis. And the amps has given me both pride and joy, so they are working well, but recently in a video somebody said that you connect the output transformer minus (black) only to the speaker jack, not to ground/chassis. And as I really don´t trust myself I have to check and double check. Looking at schematics, some are marked with the ground/earth symbol, and some are not.
What´s right and wrong here, and have I done something potentially dangerous? Thankful for input.

Hi,

I need a smps module for my Keysight scope (warranty expired) and Keysight says I have to send the scope for them for maintenance, 600 miles away from my city.

The problem is already determined and I just need the module. Does someone know if there is a supplier for these parts?

I can´t find suppliers browsing by Google.

Regards and tks in advance,

Last year, I build my girlfriend a system. First was an Akitika GT-102 and pair of Klipsch RP600M using a Douk Audio Bluetooth tube pre-amp. Cost was a consideration, and she was just getting her feet wet. This seemed like a nice compromise.

There's a ton of brass and vocals in her favorite music. Think Herb Alpert and Billie Holiday. This combination was a little harsh sometimes. I wanted to soften it up, so I built a preamp using the Glassware Aikido 12vac.

Though there's a TON of gain, the little Aikido produced the effect I was hoping for. Reproduction is smooth and velvety. We both like her system quite a bit - especially at the price point.

Skip ahead... I was looking for a quarantine project, and I've been wanted to experience a Pass amp for a long time. I set out to build an F6, but ended up building an Aleph J because I can't currently source the F6 input transformers. The Aleph J is almost done. I need to sort out an issue with one of the channels.

The working channel is sounding pretty darn good! I think this is the best solid state amp I've ever heard. My main system uses an MC275 to Fried G3's. It's difficult for me to tell in mono, but I think there's depth between the instruments the Mac doesn't quite produce. I'll need much more stereo listening to develop my opinion; but - so far I'm very impressed.

I have another set of speakers in my work area. They're the same Klipsch RP600M's I bought for my better half. I typically drive them with a Tubelab SE 300B I built a few years ago. Except for the bottom end dropping off way too soon, it's enjoyable.

Testing with the Aleph J, the Klipsch's seemed a little shouty. Maybe it's an insult to use an amp of this caliber with $550 speakers... But, it got me thinking of the improvement that Aikido pre made in the other system.

Is anyone using any Glassware line stages with their Aleph J? I'd like to hear your experience. I'd also like to have a discussion about Glassware input buffers with the Aleph J (considering the pre I built had so much gain). Lastly, I'd like to know if anyone has experienced that 12vac kit as well as an Octal kit. I was wondering what differences they experienced.

I'd be happy to start another thread about the Glassware comparisons if this is too much in one place.

I tried, but a day later it went right back to the way it was:

Hi All,

I am planning on building the O2 Amp and will be ordering PCB's from JLCPCB in China. If I order 10 boards looks like the total cost with shipping will be around $ 30.00

If anyone wants these boards I can ship them to you and thus split the cost. I am guessing within the US shipping would be probably $4/board so maybe the rough cost would be $ 8.00/board (including priority mail shipping - I am leaving some room in case shipping turns out to be more etc). If all 9 boards are spoken for obviously the cost will probably go down even more...

Let me know if anyone else is interested.

(I am based in the US so will only ship to US addresses to keep shipping simple
Also payments would have to be via paypal to avoid any additional costs)

Hello

I am repairing a JL AUDIO 1000/1. I have noticed that the amp has a idle current, oscillate of 6 and 7 amps. When I disconnect remote, the amplifier does not turn off, it takes about 10-15 seconds to turn off and it makes a loud click on the speaker.

What could be happening? There is no short film anywhere.

Regards.

Hi, I am hoping for some help.
I am new to all of this.
I have started with a Pi and Ian Canada stuff. Fifopi, Transporter Pi and also a Khadas Tone Board (KTB)


I got a second hand Ian Canada LifePO4 LPSU.

I have had some trouble making it all work and assumed it was my inexperience, but have realised that the LPSU might not be right, so turned my attention to that.

The symptoms seemed to keep changing.
One of the things is that if I power the KTB from the 5v usb the music is crackly.
But if I power it from an old phone charger, it is fine.




I started off using the 3.3v rail J2 as it seemed to be a better source.
But it has deteriorated. It now jumps about and gives between 0 and 2.98v
Then the whole thing would shutdown almost straight away if I used it saying 'short protection'
However, in the manual it says:

In which conditions the power supply will turn off automatically
(1). If run time is up, the power supply will turn off automatically to prevent battery form possible over discharge.
(2). If any output voltage at J1 or J2 is lower than 3.3V, the power supply will turn off automatically to prevent
battery form over discharge.
(3). If there is short circuit to J1 or J2 output, or the output current is too high, the power supply will go back to
power off shortly after it was turned on.

So I assume it is down to it not giving 3.3v


Also, All but two cells give 3.65v when I test them in situ.
Apart from two. One gives 3.51v and another 2.98v


Oh, another thing. The 3.3v rail J1 gives 3.65v is that normal?
Shouldn't it be 3.3v?

Sorry it is so long, but I am not sure where to start.
Thanks.

My Teac X1000R reel to reel player has a problem with its right hand capstan/drive system. The capstan breaks a photogate when it falls signalling the motor controller to increase its speed. Unfortunately something is FUBAR and instead of providing smooth control it "jumps" too far up and them drops all the way down signalling the player to stop. I can get it running if i carefully spin the right reel but that is so frustrating...

I wonder if anyone has any experience with these players and maybe knows if it's a blown transistor somewhere. The other reel works great, and it sounds great, so I would love to get this thing working properly.

Can I get it professionally repaired this day and age?

Thanks a lot.

Tade

For sale is a vintage Chicago PHC-200A high voltage plate and filament power transformer. It's a fairly rare hermetically sealed transformer and has been painted with several coats of hammertone paint. It now has a high gloss finish with swirls and patterns of superficial hammertone. It's ready to be mounted to a chassis and built into an amp.

It's used but in great shape, as you can see the leads will be easy to solder and are all intact. These units were popular for military applications and have a reputation for being very robust and quality transformers. Plus, I personally find the rounded corners and sides to be very aesthetic. I built a pair of mono-bloc 2A3 amplifiers with a smaller pair and was very pleased with both their looks and performance.

Here is some more information about the construction and the Mil-T-27 requirements involved in their design: http://www.bunkerofdoom.com/xfm/chicago1953/004.jpg

Here is the listing for the unit on the Bunker of doom website: http://www.bunkerofdoom.com/xfm/chicago1953/005.jpg

It is 450-0-450 volts at 200ma for the plate supply- 900VCT; 5 volts at 2 amps for the tube rectifier; a pair of 6.3 volt filament supplies at 4 amps; and a 6.3 volt supply at .6 amp. The unit weighs 12 lbs.

The dust on the unit is minor and exaggerated by the flash and will wipe right off (or not even be visible in normal viewing)

I had intended on building a 300B amp with it. But due to health reasons my amp building activities (all activities actually) have been drastically curtailed. So it's time to let someone else enjoy it.

Asking $60 plus shipping.

It will fit inside a USPS medium flat rate box and shipping will be $14.00 to the continental United States only (CONUS). The total will then be $74.00 shipped plus Paypal fees.

Thanks for looking at my ad!

Hello everyone,
I'm looking for a dwg file of the Eminence Alpha-15A. Unfortunately I'm not able to find a pdf file and the manufacturer does not reply to my emails. Can anyone help me?

I recently aquired a TA-377A Pre amp.

For those not familiar with the pre amp it consists of a regulated power supply, a line stage and a phone stage. The line stage and phono stage are complementary and symmetrical FET designs.

It sounds like it could be very good and I am presently improving the capacitors to try and make it even better.

However I would like some information if anyone can help.

1) Does anyone know of any articles or threads on this pre amp. I have searched this forum and google but did not find any.

2) the fets are listed as 2n3268 (J40) and 2n3269 (K81). I can not find any specifications for those. Does anyone know these fets?

Any help appreciated.

Don

Hello,

I have a Hypex Fusion plate amplifier that covers digital crossover and EQ duties. It can only apply IIR filters.

This works out well, as I wish to only use IIR filters as it avoids 'Pre -ringing' that occurs in FIR filters when you apply large amounts of EQ.

Here is an example of what pre-ringing sounds like:
This is the sound of 4 drum hits with no pre-ringing followed by 4 with pre-ringing. (I assume this is huge amounts of pre-ringing to make it so audiable)
ShortTest.flac - Google Drive

My application requires large amounts of EQ. (horn speaker).

I have set the crossover up, and EQed it. It sounds quite good.



For fun, I would next like to try and correct the phase of the speaker, to see what it does to the sound but without using FIR filters. (again due to the pre-ringing effect).

I appreciate that many will feel the phase will be in-audiable, but I would like to try anyway

I have read somewhere that this can be done by adding 'all pass' filters, which delays the signal so phase is correct. Can anyone link to or explain how this is done/calculated?

I can apply all pass filters in the Hypex fusion, or I can use any PC software you suggest.

Thanks!

Hi everybody,

This is my first post. Please consider me as an amateur with very basic knowledge about electronics and circuits.

After searching/reading this amazing forum for some time, I decided to start with TDA2050! And I built an stereo chip amp with two TDA2050. This is my first project.

I know that my chips are not authentic for sure (I used what was available). My caps do not seem to be authentic too. But anyway, I used what was available.

The power amp works just fine. No clipping, no distortion at all (dual 12V). The sound is good and powerful enough with my bookshelf Denon 6-Ohm speakers. The only point is that the sound is not as crystal clear as one expects!! The bass is fine but the high frequencies are missing.

I would be very thankful if you guys could help me improve the sound quality of my first project.

I have added both the schematic and a photo of the board. I should admit that the schematic is not mine, I just found it on the net and changed it a bit (decoupling caps).

Regards

Hi all,

I'm going to build this BHL (attached). And there are few matter I dont know how to solve.
1. How to calculate dimension of each piece of MDF basing on this schematic? Or if you built it, could you provide me exactly what happened?

2. Polywood and MDF, what's the best choice in this case? 20mm or 25mm, what's better?

3. How about the hole 67mm rite on front side, it's to hang on a treble or it's a part of enclosure?

That's it!
Rgds,

Cominup

This morning, I powered up the UPL as I do every morning, but was greeted with "Keyboard error or no keyboard present" and it's stuck there.

I don't have a keyboard connected to the UPL, but am getting the error suddenly.

Has anyone encountered this and found a workaround?

I posted some time ago about this preamp. It had some open caps when I received it. These have been replaced. My problem is the classic , " can't find anything wrong", but not working. Looking for some information on it. I have none.

I'm having another project cull...

Any interest in a pair of MoFo PCBs?



These were purchased from the DIY Audio shop where more information is available.

MoFo – diyAudio Store

Brand new, never been near a soldering iron. Offered at around 33% discount.

£10 plus postage and paypal fee

I have an exceptionally simple linear power supply used by a stereo LM3886 based amplifier I built a few months ago. Occasionally, I hear moderately load pops on the speakers and telltale sounds giving the impression a neighbour is using an electric drill. I know there is a specific filter for this, but I want to avoid using a 'death capacitor'. The usual filter consists of a voltage-dependent-resistor, VDR, with a voltage/current characteristic similar to a stretched 'N'. Two other capacitors are used but they are grounded at one end and the other two remaining ends connect to the mains' N and L terminals.

Can I effectively use a somewhat inefficient filter with resistors instead of two capacitors with one of them connected like the dreaded 'death capacitor'? I am attaching the circuit. My questions is about resistors R1, R2 and U1.

Still in original boxes. Also will include the following:

- (2) signal cables
- (1) power cable to match one SMPS600 to two NC400 modules
- (2) XLR jacks

Retail from Hypex, this would end up close to $800. I'll take $700 including shipping to you via priority mail. I take paypal and venmo. You take care of the paypal fees. Strongly prefer US buyer. You can pick up too if you're in the SF Bay area.

Built this circuit with 30-0-30 supply, driving a 17.5 ohm center tapped load. Scoped from center tap of the load to output of primary amplifier has very nice output, but the other inverted amplifier output is lacking resolution and decreased power. I do have some TL-072 chips that I could possibly employ to resolve the asymmetry issue, but would rather put those to use in a high power solid state amp. Any suggestions from knowledgable experts frequenting this forum shedding some light on what measures can be taken to resolve this issue are greatly appreciated.
Thanks, and happy DIYing! 🙂

Need help on Switch Mode Power Supply.
I have a general schematic but but its noisy. I know you can make them very quiet for tubes but i'm not sure how. I know it is going to have to do with frequency filtering.
Does anyone have any experience with SMPs and powering Tube preamps/amps?
Here is a schematic for a SMP running a preamp example. Ideally I would like to get this SMP to output 200v and have it quieter....I just am not sure how we get there.

good morning mates, its been very interesting and fun being here in this group, although i am not a well experienced audiotechnician since i was in industrial electronics in my job. I had experienced building design and DIY intergrated amps in my college days. I would like to ask you if you can just share your working complete design of a 100watt to 150 watt Class A integrated amp from PCB layout to discrete components list of parts or any Class type that brings out clarity Hi-fi audio with balance high and low frequency response, i can hook up in my Pioneer Equalizer as well. I have been an enthusiast and love audio amps. You can send me the actual picture of your amp as my guide. I will appreciate it much. Thank you very much in advance.

Ed Soriano
Dubai Audio addict.

I am looking to practise some karaoke/singing at home, so nothing very big.

I was recommended the following:

-Alto TX8 100$
-Yamaha MG10XU 200$
-Mic PG48, although he recomments the SM58, better option. 50$/100$
-2 x Jack to Jack cable. 10$

Now, the cheapest place I found selling them all, and believe me I searched lo. was a total 415 quid for all 4.

My question is, is there any cheaper alternatives ?
The most expensive piece of equipment is the Yamaha, I was wondering, maybe I buy the other stuff, and there could be cheaper alternatives to the Mixer ?

Much appreciated.

Here is a matched pair of Ken-Rad branded 307A tubes. These are directly heated pentodes and have large plates. I have used this type in triode mode with a Tubelab SE and they sound great. These are the versuions with the smoked glass- carbon coating. $75 plus shipping.

These will ship from Vienna, Austria. Payment with Paypal friends and family please.

Thanks!

FS: a pair of NOS testing ST shape 45 tubes. One is a Silvertone and the other is a National Union. These have both been tested and they test above the limit for a new tube. I have also tested these in my Tubelab SE and they sound great.

The Silvertone has a sell date of 10-10-1938 written on the tube. 82 years old!!

85 euro plus shipping. Paypal friends and family please.

Shipping is from Vienna, Austria. Shipping may take a week or so as we are currently on Quarantine because of a few sick people in our building...

Thanks -Mac

I am looking for a CD clamper for my CD10. Mine is broken beyond repair, part no. 4822 526 20174. Perhaps someone has this lying around as a donor part? I'd be happy to take it off your hand so I can restore my player. I'd be happy to pay for it or return the favour 🙂

We offer our customers a Buffer for the Hypex NC1200 module in kit form, so that the most expert users who already have the Hypex NC1200 power modules, can install them thus improving the sound quality. This Buffer includes SIL994 Enh Ticha operational amplifiers from Sonic Imagery. These operational amplifiers are characterized in that they operate in class A, providing a very warm sound similar to vacuum valves. The buffer card is ready to be able to insert other operational amplifiers, such as Sonic SIL990 or Sparkoslabs SS2590, used in professional audio and recording studios. The JRC MUSE series, AD and OPA series of instrumentation and discrete operational amplifiers can also be used. When carrying a socket, they can be exchanged so that the sound differences between them can be audibly compared. Only dual operational amplifiers (dual amp op) can be inserted into the socket. Also includes Sparkoslabs ULN regulators.



The printed circuit board of the buffer has been developed in such a way that it adapts physically to the NC1200 module of Hypex, mounting in the form of a turret so that it does not take up more physical space inside the amplifier, only a few millimeters of elevation. This board is only valid for the V4 and following of the NC1200 module (currently V6).






Info here: Buffer Hypex NC1200 | atm-audio.com


More specifications: Input Buffer for Hypex NC1200 | atm-audio.com

I am trying to interface the balanced line out of a PA system to a camcorder that has only an unbalanced, microphone-level audio input.

I have attached a schematic diagram of my first-cut design. It has a hum problem. I'd like your suggestions on a fix.

the PA system: Very low hum in PA applications. Output used is balanced, but not floating (it is two op-amps, each driving one of the phases, one op-amp is inverting, the other is non-inverting; on a Tascam LM-8ST).

Hum does not change as the attenuator in my interface box changes. Hum goes away completely when the camcorder is battery-powered.

Hypothesis: Camcorder DC power supply has a lot of common-mode 60 Hz component. The transformers in my interface box are from a Shure M67 microphone mixer; I guessed at the impedances. But I am driving the hi-Z side which is opposite of their intended use. Hence, the CMRR of my interface box may not be good (1% resistors are not great either).

Maybe ground the center of RL in the schematic (to camcorder ground)? Maybe add transformers on the line level inputs to improve CMRR? (I do have triad A67Js available). I wish I could put a common-mode choke on the Camcorder DC power supply . . .

Any suggestions appreciated. I suppose the easiest is to just use the battery power, but I'd like to figure out another solution if possible . . .

Tom

I have found a 375 watt mosfet FQA90N15.

I reckon I can get 300WRMS out of a pair of these with +/- 55 volt rails.

They have quite a high gate capacitance but I think I can drive that ok with 100R gate resistors.

Hi there!

I've now tried so many different DAC's and I have quite a collection.

Now I need to try the famous PCM1704.

Any advice?

Thank you in advance.

/Lithium 675

Hi there,

Having built several large PA rigs over the years I decided to try a lockdown 'bookshelf' speaker project. First time using winISd etc.

Parts currently in possession of / on order:

-2no. Faital Faital Pro 5 FE 120 4ohm.
-1.2 x 1.8mm 12mm birch ply
-https://zoudio.com/ AIO4CH amplifier

Looking to build a pair of almost as close to full range speakers as possible.

Anythoughts . comments would be great.

So far I have 2 designs a 6L and a 9.1L enclosure.

project - Album on Imgur

Hi, i have an old smartphone and i want to build a full range system (as the speaker of the smartphone died)

I have a few full range (and old) CSS FR125S and i want to build a stereo system. Plus i have many LM3886 amps.

Want to know if will be OK to connect directly to the headphone jack or will be safe if use bluetooth.

Plus will be great if someone know some good designs of small systems like the one that i want to build!

Thanks

Hello everyone,
I'm thinking of making a project with the scan speak 18w8545-01
I have a doubt on tw
candidates are:
http://www.scan-speak.dk/datasheet/pdf/d2905-950000.pdf
http://www.scan-speak.dk/datasheet/pdf/d2608-913000.pdf

the D9500 costs double the D9130, this price is justified?
9500 seems to be less sensitive with a impedance curve worse.
however, has a lower fs
9500 looks worse than 9130
anyone compared them?
I would like your advice
thanks

Hi all.

I am having a massive clean out and will have many old triodes and some other tubes for sale shortly.

First on the list is my stock of 45. I have 24 x good testing or new in box valves as per the attached list photo. I tested everything on a calibrated I-177 tester. Micromhos values are in the second columns.

There are 5 very strong matched pairs from the used bits. I'm not going to take the 7 NIB ones out to test. (Note, I have one more JAN45 NIB not on the list).

I'm shipping from NZ. Not so keen on sending individual tubes. Bulk buys appreciated and I'll probably work with you a bit on price if you want more than a pair.

If you have a lot of posts on diyaudio, I'm happy to guarantee them. If you don't, I won't guarantee. I've been burned in the past for a pair of 71A by a runner and I won't do it again. TRAN HUU THUAN, was the dude if anyone knows him.

If you have helped me out on any of my posts in the past, send me a PM and I'll hook you up with a sweet deal. Otherwise, prices are: $125 for premium pairs (Gm ~ 2600), $110 for strong pairs (Gm ~ 2400), $85 for good pairs (Gm ~ 2100). If you want the NIB ones, they can go for $85 a piece or $150 a pair. All prices in USD. If you wanted the lot, $700 would take it home and I'd throw in a Covid19 shortage-inspired role of toilette paper.

You pay shipping and PayPal fees.

Next up will be 01a, 4p1l and some random old UX4 numbers.

Thanks for the community guys.

Best regards and stay safe with the Covid19!

Hello,
I was having troubles with building a rat clone as you can see here:
Proco RAT Clone doesn't work
The problem was fake LM308.
So I rebuild the circuit with what I had and I made some mods. I'm pretty sure all these mods have been done by others too.


So I am posting the schematic!

FWIW I figure 3/4 cubic foot would be enough volume - dunno if 9mm BB with a few braces would be stiff enough or not.


for helper tweeter I've an ST200 or maybe the old slot ST324

could RJ vent it

Purchased a few years ago, but currently unused, I have the following for sale:

• 2x Universal Filament Regulators (V3.2) ($20 each)
• Maida Reg 1.0 ($40)

$70 for the lot.

Shipping from Australia.

I found a large bag of mpsa42g in my parts bin. I used to do a lot with tubes, so they were probably for a ccs or something. Are they usefull for a preamp or buffer of some type? Does anyone have a proven schematic?

Thanks,
Chris

Greetings,


I was looking for someone to build a CMoy modified to be suitable for low impedance and low sensitivity headphones or another DIY amp that would be suitable. No other requirements (though I'd prefer it use regular batteries like AA or other cells, 9volt would be okay).


Thank you for looking and specifically, these would be for a 7th Generation iPod Classic & Audeze Sine headphones. Headphone specs are below:


Specifications
Style


On-ear, closed-back


Transducer type


Planar Magnetic


Magnetic structure


Fluxor™ magnet array


Phase management


Fazor


Magnet type


Neodymium N50


Diaphragm type


Ultra-thin Uniforce™


Transducer size


80x70 mm


Maximum power handling


1W RMS


Maximum SPL


>130dB


Frequency response


10Hz - 50kHz


THD


<0.2% @ 100dB


Impedance


18 ohms


Sensitivity


97 dB/1mW (at Drum Reference Point)


Minimum power requirement


>100mW


Weight


320g

Is VS1003/VS1053 suitable as a DSP/Codec controlled by Arduino Nano

Hi,

I would like to implement the following logic in DSP/Codec

1) Use a microcontroller (Arduino Nano) to control VLSI DSP using SPI or I2C or UART.
2) Use ADC with sampling frequency of 8Khz for ADC/DAC and DSP processing.
3) Reverb with initial delay of about 50ms.
4) 3 PEQ filters. Separate PEQ settings for each channel.
5) Change filters of both the channels at run time while system is running
Two independent channels. Means:- reverb delay (3) and PEQ (4) unique to each channel.

Can VS1003/VS1053 be used as a DSP/Codec for above purpose?
If yes, what documentation and where should I start reading?

Thanks,
WA

Any idea on what to check in this amp ?

With just power and ground it powers up .

Not sure if it’s a diode transistor or 1 of the networks

Earlier this spring I purchased a DAT unit at a local garage sale for $5. Finally having some time to mess around with it a bit more, i've determined that its defective, at least the dat mechanism part which constantly eats tapes. Now i'm trying to decide about what I'm actually going to do with the unit. First off, even if I decide to just totally junk the thing, it is completely massive (at least 35lbs) and should have some very nice parts.

So I guess right now I'm just debating whether or not I should try and fix the thing, or junk most of the insides and use the very heavy duty copper plated case to house my first chip amp project. I don't really have a use for a dat machine *right now* but this is sony's FIRST ever dat machine, so I feel as somehow fixing it might be worth it. Anyone know where I could get schematics for the thing or better yet a repair manual?

If I were to put a chip amp in there, I think I'd try Chipamp.com's 3875 kit, unless anyone can recommend something that is significantly better, i've never made one of these before. But in the case that I do that, I'm wondering if the heatsink will be big enough, dimension wise the sink is: 3x2.5x1.5 inches, the case being 17x12x3 inches, a bit low if I want to fit a torroid transformer in this thing right? maybe the built in transformer will work? I havent tested its specs yet.

Any recommendations or suggestions would be greatly appreciated, Attached are some pics of this beautiful unit:

Let us consider the typical two-way design of two speakers. The drivers are identical for speaker A and B. They are the same crossover point used. Speaker A uses Q at 0.707 on both drivers, the other uses Q at 0.49. Both speakers are measured flat frequency response. Will they have the different in sound?

Collecting components for a passive preamp, is it possible to parallel RCA outs on the rear and use the second set as line level subwoofer inputs? Would this cause any adverse effects?



Source: RPI DAC TBD
Speakers: 8ohm paradigm signature S3

Subwoofer: SVS SB-3000

After three years of collecting parts and working on a chassis, I finally have all the parts I need to finish this thing. I'll start wiring this week....I hope.

Finally found time today to start the assemble process. I have just a few more things to do then I can start wiring this thing. Man is it heave.

Hello all,

I have reached the end of a 300 hour build of a (mono) Le Cleach type front loaded horn just over 4ft in width with a mouth exit curve of 112 degrees. It has both back and front chambers, and as a prototype, I consider it a relative success - for now.

It was modelled in Hornresp around a 6.5in Visaton BG17 (full range with a whizzer) and also a 6.5in Jensen guitar speaker. Why these? Because I had them already, and they are cheap enough to thrash and trash.

At first, the Visaton seemed quite nice, but I suspect the whizzer does not perform very well inside the compression chamber. Somewhat congested, and a bit shrill. It lacks bass, and although lively, it is quite tiring on the ear. The Jensen has much better bass, mids seem nice enough, but lacks clarity in the treble. Both drivers benefit from the use of EQ, and although I love to sit and listen and sing and dance in front of this massive horn, I feel that there is a much greater potential for musical joy as yet untapped.

There does not seem all that much to choose from out there for 6 to 6.5in full range drivers. However, I have read about the 6in MarkAudio Alpair 10M Gen 3. Its physical spec suggests that it would easily fit without having to modify the existing enclosure. My question is, would this driver be suitable for a front loaded horn? And, with its long throw design, would it give a decent amount of bass without an excessive use of EQ?

For what it is worth, I am a practicing artist working with vision and sound, and although technically accomplished, I am NOT an audiophile. My taste in music is, shall we say, eclectic. So long as it engages my emotions, I will listen to anything. As for builders passion, it is horns for me - magical and beautiful.

I would truly appreciate some help with this.

Kindness tapestryofsound

I have left over capacitor and i need money due to COVID 19

Please DO NOT LOW BALL

USPS Money order only

I used this all very light less than 2 weeks before

3 pcs used Jupiter Bees Wax .047 Uf 600DC V@$25 each
1 pcs brand new Jupiter bees wax .047 uf 600DC V @$30
2 pcs used Jupiter Bees Wax .22 uf 600DC V @$42 each
1 pcs used mundorf Silver Oil 2.2 uf 1000 DC V@$75

I will give you FREE PRIORITY MAIL SHIPPING Free if you buy all of them
otherwise shipping inside CONUS will be $10

please PM me

I have 3 pairs of these fantastic RCA sockets, which I somehow managed to order too many of.

Loads of information at Audiophonics.fr on them.

£20 per pair, inc UK postage.

This is a £15 saving over the price to get them from Audiophonics.fr directly.

Thanks,

Oliver

Cube Audio Nenuphar, 10" single driver loudspeaker, AVShowrooms Feature Review and Listening Session -

YouTube

Toroidal Transformer for High Power Build

Originally From a 1000W Subwoofer Plate AMP

1000VA
115VAC or 230VAC primary winding
Secondary 1: 97.8V - 0 - 97.8V
Secondary 2: 0 -19V
Secondary 3: 0 -19V
~5" Dia, 3.5" Tall
Weight is about 14 lbs.
Includes mounting plate.


Note; The output voltages could be cut in half if 115VAC were applied across the 230V primary winding.

I can also throw in the rectifier / bulk cap board that provides +/- 140VDC, and a 12VDC keep-alive. Bulk caps are 2200uF 200V


Asking $50 + shipping. USPS flat rate should be $15 or less to USA address.

Please review this schematic and let me know your thoughts. based upon the Sakuma principle with the driver tube = output tube. I am curious about your thoughts for any improvements or if it looks OK, then please confirm.

Thanks

Need help for wiring Class D amp (VGATE)

Hi amigos,

I need some help to get the right diagram to wire my NewClass D double Mono amplifier. The problem is : My SMPS 800W PSU does not have any Aux voltage. I need to add another 24V DC PSU for the Vgate...

Can you help me to complete / correct this diagram ? I just need to know how to connect the V+ / V- from the 24V PSU into the Amplifier Vgate input.

This is my actual Setup



Thanks for helping

Dear friends,
During the past decade I collected a lot of loudspeaker drivers, some of them for my particular projects, some just to feed my curiosity.
I made duly measurements for all of them which I decided to share in a dedicated web page as well as some of my loudspeaker system projects.
I am starting with eight-inch fullrange drivers, some of them measured in a specially constructed "Universal" Horn.
I hope this information will be useful for many audio DIY-ers.
Here it is:

Loudspeaker Raw Driver Measurements

I've started with the followed drivers:
Coral Beta 8
Fostex FE-208 Sigma
Fostex FP-203
Lorenz S-888
Pioneer PIM-8L
Tang Band W8-1772
More measurements will come soon...
Any comments and suggestions are welcome!

Wondering if there are any good mods for the 545II that give good bang for buck?

I had a 535 once, and Mr. Pass told me to swap out the input fuses for 5w ceramic and all I could say was WOW. Huge improvement.

I have re-capped a Harman Kardon PM655VXi and it is putting a ton of clean power. When I try to adjust the DC offset, it is going up and down by about 20mv on each channel. Is that a sign of a problem? Everything looks good on the scope. The amp heats up when idling but they're known to do that and it isn't a bad heat. Thanks for any help or advise.

Hi all , how do you tell which side to read a resistor from ?
I have this burnt one , but should it be 470 ohms or 210 ohms ?

Have just bought myself a Hammond 370HX and two Hammond 1650E output transformers for a el 84pp prosject .But which amp shall I build? My first thought was the KEL 84pp, but I see that there are plenty of different schematics out there. Which of these two?

Below is the line filter of an Ampex tuner I'm working through:



During recap I'll be replacing the two .005uf caps between the line and ground with type Y .0047uf safety caps. Can I clip out the 1meg resistor or should I leave it? Why is it there to begin with? Thanks

Hello, I have one pair of 45 tubes, brand is Sylvania, green label. Good condition but Ive not measured them, I think they are 80% minimum (I have built an amp with them). But I dont have much money and it is not a good idea to build an amp when you have just 1 pair of tubes.
I will be happier to change these tubes for pair of some good output transformers, single ended, 5k and 100mA current will be great. For 4 ohms speakers.
Best regards, Michal

A friend has asked me to build him a tube amp for his three headphones that are 25 ohm (AudioQuest Night Owl), 110 ohm (Audeze LCD3), and 300 ohm (Sennheiser HD650).


He loves Lundahl iron so I thought about the LL2765 OPT (30mA, SE) with its configurable secondaries for 32 ohm, 150 ohm, and 600 ohm.


Are those OPT impedances close enough to my friend's phones? I worry about matching the 300 ohm Senns.

Please feel free to add any FR drivers that you think is worthy of the list.

FR = ''fullrange'' than can cover at least 7 octaves
efficiency 1w/1m 90db+
retail cost no more than 50$USD or 50EUR per unit.


*** I will update the list on post #1 if you have good suggestions that can help others. ***


FaitalPro 3FE22 33$
FaitalPRO | LF Loudspeakers | 3FE22



Faital 4FE32 40$
FaitalPRO | LF Loudspeakers | 4FE32


Visaton BG 13 P 16$
BG 13 P - 8 Ohm | Visaton


FaitalPro 3FE25 20$
FaitalPRO | LF Loudspeakers | 3FE25


FaitalPro 4FE35 26$
FaitalPRO | LF Loudspeakers | 4FE35


Visaton BG 17 19$
https://www.visaton.de/en/products/fullrange-systems/bg-17-8-ohm


Visaton BG 20 38$
https://www.visaton.de/en/products/fullrange-systems/bg-20-8-ohm


Monacor SP200X 45eur
https://www.monacor.com/products/components/speaker-technology/hi-fi-full-range-speakers/sp-200x/


Beyma 3FR30 45$
https://www.beyma.com/en/products/c/full-range/103FR308/altavoz-3fr30-8-oh/

Attached is the schematic of a supply I have bread boarded here. Using a load of 4,910 ohms, (because that's what my big *** resistor is), the supply outputs 275 volts and draws about 54ma. With no load resistor the output is 328 volts, 0ma.

Next I wanted to see how much ripple it had. So I set my Fluke multimeter to AC and measured the output as AC. With the load resistor it reads an average of 70mv AC. With no load it reads an average of 2.5mv AC.

Are these acceptable ripple readings? Did I do this all right or am I all wrong herein how this is done? Is the ripple percentage a simple ratio of the DC voltage to the amount of AC ripple?

If its that simple then 70mv / 275000 =.00025% ripple loaded; and 2.5 / 328000 = .0000076% with no load.

Am I way off here in technique to determine how much ripple I have?

Hello,
I'm looking for some catalog or datasheets of Siemens foil capacitors from year 1960 - 1970 like:
B21990-A0704-G1
B25990-A205-K1
B31096A
B31190-S2
B31190-K9
B31212J

Inductors, small signal trafos, like:
621 C 467
621 C 469
621 D 1118
621 D 1116

Thank you
Michal

Hi, first I want to thank the forum for the great expertise and collaboration that provides to DIY Hifi enthusiasts like myself. Second, I want to explain my system and try to get answers and feedback to my questions.
I am new to the forum however, I have been experimenting with hifi sound systems for many years. My system is 4-way with active crossover and comprises of the following:
• 2 McCauley 6174 subwoofer drivers in individual vented boxes (13.15 ft3 or 372.4 liters) tuned to 20Hz driven by a professional Carvin DCM2500 amplifier.
• 2 McCauley 6224 woofer drivers in individual seal boxes (1.337 ft3 or 37.9 liters) each driven by its own VTA M-125 Monoblock tube amplifier.
• 2 ATC SB75-150 mid drivers in the same box as the tweeters driven by its own VTA M-125 Monoblock tube amplifier.
• 2 tweeters RAAL 140-15D driven by professional Carvin DCM600 amplifier.
• NAD Preamplifier C 160.
• NAD CD player C 521i and a Linn LP12 turntable (almost ready with Audio Technica MC cartridge and step-up transformer).
• A Rane AC24 active crossover (4 way) driving all power amplifiers.
This system, although not complete in terms of upgrading amplification, sounds good (relative term) to my ears. I can clearly distinguish each musical instrument and I must admit that the mids and highs have some of the best fidelity I have heard comparing to systems that cost much more $. In addition, the 6174s from McCauley are monsters when it comes to low frequencies generation.
My issue is the bass guitar does not sound as live and as high fidelity as I expected. I think that the 6224 McCauley’s should sound more realistic and defined.
My question is what is the best (relative term) hifi 8”, 10” or 12” driver for the frequencies of 80Hz or 100Hz to 800 Hz. The crossover points in my system are 100Hz, 800Hz and 3,200Hz. Thank you in advance for your feedback.

Is it possible to upload a 10/12 second video? Which format?
Many thanks.

Hi everyone,

I have some rough looking but functional Celestion Ditton 25s and some quite nice and fiunctional Beovox 5700s.

The 25's cabinets are poor and water damaged and even if mint they'd still be made of chipboard so not that great by modern standards. The 5700's are ok but the driver placement is awful so they don't image as well as they could. I have also read that the cabinet volume is too low for ideal bass performance.

So, I'm thinking of using these speakers as donors for something better.

With these speakers, I have all the drivers for a pair of Ditton 66s and the crossover schematics are available so i could make those too. Or I could refurbish and sell the 25s and rehouse the 5700s in taller cabinets with the drivers aligned. If I did this I would need to know what volume increase to go for. I do not know what is the optimal size for the Philips 10 inch unit and ABR. I am not sure TS info. is available for these drivers so I'd need to rely upon someone else's experimental results.

What are your thoughts? As nice as these old speakers are I can't really see the point of preserving them for the Nation as they are mass market items and somewhat flawed but I believe that a sensible modification of the 5700s or a combination of the both to make a 66 type speaker in 1 Inch thick ply could be quite special.

I have electrical/electronic knowledge and woodworking skills but I have not tackled a project like this before.

My current speakers are Acoustic Research AR55BX 3 way which I refoamed, rebuilt the cross overs and added a magneto dynamic tweeter to replace the blown originals. Amplification is a mid range Marantz receiver and my main sourse is LP via an old Garrard/SME combination.

Yours with thanks,

Jolyon.

Hello All

I have a Sugden A28 II amp. (external heat sink on the back). I know nothing about amplifiers. I bought it new about 30 odd years ago. I really like the amp, but it has some issues. I was hoping to get some insight/advice from the learned members.

Problems:

1) When I turn the amp on, I get a loud "whooomp" sound from the speakers. (Vandersteen 3C signatures, if that matters) Am I damaging my speakers? What can i do to eliminate that sound???

2) I get a crackling noise as i turn the volume knob.....only while moving the knob.

3) Turn the selector knob to aux (where I have the CD player) CD player off. Tuner on......turn up volume...you can faintly hear the tuner. Not a problem, just wondering if that indicates an issue that should be fixed.

4) At thirty plus years old, should I replace anything in the amp while I have it into the shop to address the above issues? ( i have been reading people in the forum who talk about replacing capacitors and such)

Any advice/insight most appreciated. I want to have some idea what i am talking about when I take the unit in for repair.

Thanks in advance!!!


Darren

Hi,
I'm building and collecting parts for the Borberly Op amp 4.
I have two good Philips ECC86 and all the transistors, the rest of the parts are on their way.

This only my second attempt at building with tubes, except for fixing a small tube amp.

I've opted to go for Allen Bradley resistors(but also have Vishay and Roederstein at home), Silver Mica for 22pF, Wima's for 100pF. Don't know if polystyrene would be better caps in this application? I will populate R15 & C5(100pF I read somewhere, can't remember where atm), is there any drawbacks to this?

This circuit is to be used as output on a DAC directly after passive I/V and followed by a matched pair of NOS 2uF russian PIO's.

I've got a 2x24VAC transformer rated at 30VA(625mA if my math is somewhat correct), I hope this will be enough for the two ECC86 and the two pairs of 2SK216/2SJ79 (not matched btw).
Filament supply will be handled(if possible) by a 5VA 0-6VAC transformer (220V primary, we have 230V mains).
I'll have to measure it when it arrives to see what the secondaries actually deliver. If too far off 6.3VAC, I'll use a bridge rectifier and LM317 set to 6.3Vdc.
If wiring the filaments in parallel to the PS, 6.3V is ok I suppose but if wiring them in series I'd need 12.6V? As stated I'm fairly new to this.

For those of you that do know this stuff, is there any issues with DC offset/drift with this design? I assume the 100R trimpots are for trimming DC as no two halves of any tube is 100% identical.
If there is issues with DC offset, how have those of you that have built this circuit handled it?
The easiest, but I doubt the best, way would be to swap the 200R (or 165R?) for trimpots I assume?

For the current source, I have two J511's on their way, they should to the job?

What are your opinions of the sound quality of this design?
I'm hoping it'll atleast beat opamps and maybe the ECC86/2SK170 SRPP hybrid I have in another DAC.

Hello,

I have 4 x DC160-4 Classic Woofers and 2 DC28F -8 tweeters for sale. These are new in box. My plans for building MTM or MTM-TL have changed with a new house. I am asking $100 usd plus shipping for the whole set. Please PM me if interested.

MM

Hello everyone,
It seems a pretty stupid question to ask, Have anyone ever tried to build a toroidal variac by their own ?
Here collecting variac is very difficult and the price is so high, and most of them are of very big and high powered ,for industrial use. That's why I am thinking about a project to build a variac by myself. Will it be impossible. I can collect smaller toroidal laminated core. But I need technical information about Winding,which is the most difficult part. I want to build a variac that can supply 0-300 V , Is there any resources ,or books on Variac construction, cause it seems the winding is very delicate and the volt/turn calculation as well as core calculation have to be precise. Can you guys give any suggestion, or resources about Variac winding process.?

Thank you

Rectifier datasheets often specify minimum plate impedances, but can I get away with using one big resistor after the rectifier (but before the first filter cap) instead of putting two resistors on the plates? Like so:

Hi all,

I’m working on building a clock board for my CD player at the moment. At the minute it’s got one of those inexpensive boards from eBay on there which works very well: 15MHZ TCXO 0.1ppm Ultra precision Crystal Oscillator CLOCK+PSU board | eBay

But of course - always room for improvement especially with very low cost parts 😀

The board alone sells for about £3 and the crystals seem to sell for about £15. The sellers claim very low jitter on the crystals (one of them I can’t find now posting an alleged comparison graph with a Tent XO and coming out very similar)

Does anyone have any experience using these cheap TCXOs for me to reuse on a new board, and are they as good as they claim or would something like a Tent XO give better performance?

Hello, could someone help me to get the 2200uf 63v capacitors that my pass labs x150 has, which are of quality since they are axial type and I do not see quality things