Every time I turn on my 67cd power, the disc in 67cd turns very fast counterclockwise and there is no readout shown on the screen. After several turn on&off power, it becomes normal. Does anyone know the root cause? control IC or spindle motor problem? Thanks!

HI,

I am planning to build 2 Tham 15 based on this design and am looking for a DX file of this or a similar design to give to my local plywood shop to cut to size

https://www.martinsson.cc/blog/index.php?entry=entry090721-180410

I am new to this so hoping someone can point me in the right direction

Thanks

Paul

Hi Fellow Audiophile nerds,

I know everyone likes to put a plug in for whatever products they happen to have in their system. I'm no better. But, I thought it would be worth sharing my experience with the ifi Zen Stream paired with an upgraded linear power supply, because it sounds great and seems like a really good value for what you get.

The ifi Zen stream is a small device, purpose built, with USB output. It cost me $400 USD on Amazon. Has been favorably reviewed by many including Absolute Sound, Audio Excellence Canada, and others. Some reviewers mentioned issues connecting to wifi, but I haven't had any problems. Ifi claims the product downloads firmware updates automatically. Streaming via Tidal Connect has been rock solid for me thus far.

I added a linear power supply from a British company called McRU - recommended by the British Audiophile. McRU makes a power supply for the Zen Stream and it costs around $350.

So, with this $750 combination, it seems I have a streamer with most of the features that you would find in high-end streamers from Auralic or Aurendor, and they retail from something like $3500 and way up. What I don't yet have is I2S output and a really good internal clock to reduce jitter before going into my DAC. But, Denafrips offers 3 digital to digital units, with their entry level Iris going for about $550 USD. So that's another option for those wanting to improve performance further.

How does it all sound? Going from a Bluesound Node 2i using coaxial output into a Denafrips Ares II, to the Zen stream with upgraded power supply USB output into the Denafrips Ares II the upgrade was very significant. More clarity, darker (less noisy) background, better instrument separation, and overall the sound seems to have a bit more weight to it.

Just thought I'd share this, and would love to hear others' opinions and experiences.

Hi,

I'm thinking to start first project with Kairos 3 way.

I understand that I can't change the angle on the front TM baffle, am I right?

Any idea for simple cabinet design for this kit?
Classic design would be great, or something more sexy than the original Kairos 3-way design.
I have basic wood & audio skills but I want to learn through this project. I can use wood workshop/CNC if needed for certain parts.

I have 3.5m X 4.5m room, so I think to make the woofer cabinet as small as I can, something like 400mm X 400mm X 400mm, and maybe with small stands - Is it possible? even that I prefer classic design or something more attractive.

I have SVS SB2000
DENON AVR-X24000H - After the speakers build I'll find good amp
Music: Rock, Rap, Jazz, Indie & Blues.
Source: PC (Tidal, Hi-Res, Deezer & Spotify)
90% Music / 10% HT
Soon to buy miniDSPs
Listen alone most of the time and not loud - regular.

Thanks!

Itamar.

Hey!

It's been a while, but I've been noodling on a design for a 20W PP amp and decided to take a whack at a 6L6GC UL PP. Not sure that it's all it could be, but I wanted to keep it simple.

I have attached the schematic in progress, but should mention that the driver circuit is from the EL84PPP in this post and seems to be fine to supply voltage gain for the 6L6s.

LTSpice is indicating about .17% THD with 6dB of global NFB at 10W with about 20W of power available before clipping. 2H / 3H are about -58dB down at 10W / 1kHz.

Thoughts from the community would be much appreciated.

Kofi

Greetings!

As I have described in my introduction, I am weary getting into a DIY game for fear that I will get sucked even deeper into the audio rabbit hole, yet at this point in my hobby I would like to experience that SET tube sound, and I am on the budget. Hence, I am looking for someone to take my money and build me a device so I could just try to concentrate on enjoying the music for a bit and not look for the next thing.

I am in Berlin, I guess a builder from Germany could work, but ideally it should be a builder from Poland - I want to go with Toroidy.pl parts, and having a builder in Poland will allow to save a bit on shipping I suppose.

The build I have in mind is relatively sophisticated:

• I am looking for a power amp, so no volume control or input selection - just one line in;
• I would like to be able to use both KT88 and EL34 tubes, so will need a way to adjust bias;
• I would like a tube rectifier;
• I think I don't need the SS to tube rectifier switch, and, accordingly, the SS rectifier installation can probably be skipped altogether;
• I would like an auxiliary power supply cap;
• I would like a switch between the UL and SET modes, but if having the UL mode increases the cost of transformers (sorry, still a bit shaky on this part - I think the transformers have to support the UL mode?) then only SET is fine;
• I am not sure if I need a feedback switch, or if Toroidy.pl transformers are producing enough bass response as they are;
• in terms of enclosure it's up to the builder really, something simple with wood and metal plate is fine with me.

Of course, I will be willing to discuss and make compromises so that the optimal performance/flexibility/price is achieved.

I'd really appreciate if someone would take this on, please PM me if you are ready to do so.

Thanks in advance!

Hi,

I wrote a Python package to:

• Use USBi as a general-purpose USB-I2C converter.
• Control I2C devices from PC.

Please see USBi tools box.

I was going to buy DATS so that I could get the "real" T/S paramters for finalising my enclosure design. And then use DATS to get my in-box impedance curves for my XO design.
However after doing some reading, I've decided to just rely on the manufacturer's published T/S parameters.
Which means I would only be buying the DATS for the in-box Impedance testing.

But I have been using REW for quite a few years, and although I haven't actually used it to do impedance testing, I am hoping that I would be able to get reliable results.

Is anyone familiar enough with REW to be able to confirm that REW would give me fairly accurate in-box impedance curves?

Some of you may recall Monsoon audio -- for a time (late 1990-early 2000s) --- they became hot sellers due to their PC-related sat/sub models.
They sound quite good (mine are about 21 years old, but I retired them after about 2 years due to subject of this thread).
Both sats have a "buzzing" distortion over most of their freq range. They sound as if they are "blown" but BOTH being blown would be rare.
I think I've read that their powerful magnets can attract dust and that clogs their diaphragms.
The drivers are RIVETED shut so disassembly would be somewhat destructive. Don't want to do that just yet!
But I am open to other suggestions. E.g., how delicate are the film diaphragms to, say, compressed air blow-out?

Both treble and bass potentiometers can be either the linear or logarithmic type. Sometimes I see diagrams with "logarithmic" and
sometimes with "linear" noted in the diagram and most of the time there is nothing said or written about its type.
Can someone here shed some light upon this subject please? Or supply some links where I can read about it?
Of course I know the difference between those potmeter types 🙂
but anyway....

Hi everyone. Hopefully i'm in the correct forum.

I'm building a condenser mic and I supply it with about 80V dc from an Hex Inverter cmos circuit. The circuit I followed is attached. The cmos is supplied by +12V dc. I wonder if there is a circuit that provides -80V dc from the same +12V dc source -since it's provided by phantom power -(maybe by using the same circuit and changing something to give me negative bias).
I don't think that reversing the diodes' bias would work.

Thanks in advance

Ps.The voltage regulator and trimmer in the voltage input of the circuit are ommited.

Hi,

I would like to ask your comments on a design I've implemented on SS starting from George (Tubelab) UNSET (see details on dedicated section of the forum).

Driving a N-channel Depletion-mode DMOS (I've used the LND150 because they work well with high voltages, available where I want to implement this circuit) from the cathode through a pmosfet and giving local feedback through a voltage divider from drain to gate to ground.



Curves are very promising, and of course the local feedback (and so the reference gate voltage of the pmosfet) can be modified accordingly to change the curves of the two mosfets.

Of course the same concept can be applied to other SS devices too.

Thanks in advance for your feedback,

Kind Regards

Hi folks,

After probably a year of good use of my Hafler 9505, it suddenly got noisy in the right channel. The amp is used for mids/highs in a bi-amp setup. I verified it's the amp by switching the input to the amp with the left channel (noise stayed), and also by hooking up a different speaker (noise still stayed). Exercising the bridging and balanced/unbalanced switches did not make a difference.

When I got this amp, I resoldered some of the more baked solder joints in the high temp areas of the board, but didn't proactively replace anything. I haven't yet opened it up to take a fresh look, as it's at the bottom of a stack of equipment. I'll probably pull it tomorrow. Just wondering whether there were some common failure points in these.

Thanks,
Paul

Hello guys , I was searching the site for help on how to wire the greyhill switch to a noble pot but the only one that I found was one post by Peter Daniel a long time ago but Am confuse a little bit, here what he said :

I buil a stereo power amplifier using this power supply cicuit and I still have pop or click noise when there is a noise on mains ( like switching on or off a pvr or any other equipement )

Should i get rid of the insulation circuit betwen chassi ground and mains ground ? or what would be the next step ?

I installed the Academy Audio Muses digital volume control in the line stage. It had a Goldpoint 50k stepped attenuators. Now there is a difference -
the unit is really more transparent and refined. But I would like to know why this is so. I installed the kit for the remote convenience even without a led display. It is easy to install just replace 2 resistors connect and ready to go. Recommended.

I have set of speaker 2 pc from phillips company 8 ohms. how to know its wattage. I am intrested in DIY BLUETOOTH SPEAKER.

For sale is a fully built, and tested pair of XRK/AKSA (Hugh Dean designed) ALPHA 20 Class A amplifier boards. ALPHA stands for AKSA Lender P-Mos Hybrid. Boards have been cleaned extensively for removal of all flux. A generic set of 10uf input capacitors are included for the owner to install if preferred. Input BJT’s are matched (for Hfe) for super low dc offset (<5mV). Output FETs are the very expensive IXYS types. This is yet again an excellent sounding circuit using Nelson Pass‘ Aleph CCS in the output stage, biased at 1.8A. Gain is set at 18dB. More info regarding the circuit is right here. Board is UMS compatible.

Price is $OLD/pair fully shipped in USA. International shipping is possible at extra cost. PayPal preferred.

Best,
Anand.

Fostex cabinet for FF225WK . It's a go !

Built per ZM’s explicit instructions, I have a fully built and tested pair of Aleph J Zen boards using a matched pair of Linear Technology J74’s and IRFP 150’s. Input capacitor has been removed but I am including the standard 1uf WIMA capacitors. Board has been fully cleaned to remove all flux. Fully biased and tested. Another excellent circuit that tests well and sounds great on my NPXP. Board is UMS compatible.

$OLD/pair fully shipped in USA. Will ship internationally for extra cost. PayPal preferred.

Best,
Anand.

I wrote this for personal use, but in case it's useful to anyone else, I have made it publicly available. It's a Windows* command-line utility that takes a CSV file from an oscilloscope of a frequency sweep across an unknown impedance and tuns it into a CSV of impedance vs. frequency so it can be turned into a chart.

* It's Windows-only due to the way it's been packaged. If you're willing to compile it from source then it should work on other OSes too.

You need a setup like this:





To capture a frequency sweep like this:




Which OIC can process so it can be turned into this (actually not from the same speaker as the above image, but you get the idea):



It's available on GitHub here: https://github.com/cheese83/OIC. I've also attached both the executable and source code to this post.

Hi everyone,

I bought a pair of Tannoy S8 LR DC units(2064) . I am planing to build diy S8 LR cabins.. Unfortunatelly I could not find the xover shematic and parts list of S8 LR speakers on the net. I found some pics of S8 LR xover only. You can see it the pics below.. The values of the parts on it are clearly visible except of the coil... I have no idea about the specs of the coil.

If anyone knows, please help..

Thank you..

Hello to all diyaudio users,

I bouhgt not working Arcam Alfa 5 CD player. When I got the package, it turned out to be Arcam Alpha 5 plus. ( better CDM and separate clock power suplly ). Inside Arcam I saw TDA1541 S1 with crown. I decide to repair it.

I found and order new CDM9 pro version I repalced it. Now CD player works but... :

- when I use digital out connected to my Musical Fidelity DAC everything sound great.
- when I use analog out on cold player sounds great but after few minutes start hear noise from both chanel ( temp. about 45 C ). First low noise but after higher temp inside ( about 50 C ) louder. Over temp 55 C analog output is dead, zero music, zero noise.
- when cd player is connected to power inside temp is stil about 45 and in analog out still nothing after start.
- when I disconnected Arcam from power suplly and has an ambient temperature everything play after conneted to warm up.

It see like something is wrong with analog line, what I should check first ??

Capacitors around TDA looks not good but it can give noise in analog line ??



Or maybe TDA1541 is broken ?? but why I have still good sound on digital out ??

I have full scheme of this DAC but my knowledge is not that high 🙂

I've been offered both a HP3580A and HP3582A at an attractive price.

I'm definitely going to buy one of them but can't decide which is the better bet. On the one hand I'm tempted to think that the 3580A will be easier to repair and keep working but the 3582A is the newer and more powerful tool.

Which would you go for and why?

I have a pair of fully built and tested Aleph J boards. Included are 2 pairs of input capacitors gratis, if you want to immediately install these boards into your amp and get going. All flux has been cleaned and it is now brand new. It’s already been biased and dc offset has been minimized. JFETs are a matched pair of NOS 2SJ108V’s and Gain/Aleph CCS MOSFETS are matched quads of IRFP240’s courtesy of member Dennis Hui. Played them extensively on my NPXP amplifier and this is an excellent sounding circuit. Gain is right at 20dB.

Price is $OLD including shipping in the USA. Extra shipping for overseas shipments. Paypal preferred.



Best,
Anand.

Found them, from a forum member. All set!

Interested in making Euphase KM-U2. Need shipped to California, 95521.
Thanks, Don

Custom made - no hum! toroidal transformer, ideal for chip amplifier. See picture. 160VA , 120V, 4x22V.
$100 shipped conus.

Hello !

Maybe somebody has a schematic for CEC AMP3800 ?

Initially had a humming noise on right channel, discovered floating ground on RCA input, rectified but after several hours come into protection mode, display: "ERORR".

Somebody, few years before, repaired one of driver cards (the left one).

I have no diagram and I need one.

Thanks

To keep the power supply part of my tube headphone amplifier away from the amplifier part
I use XLR Neutrik connectors and braided cable mantles for the power supply lines to the amp part.
But the way I have done it does not satisfy me (see attached photo).
Those coloured tapes and the mantles will loosen after a while and I have to redo that taping and mantle connection to the connectors.
Is there a nicer way to do that job?
Of course I want to keep using those connectors because they do an excellent job.

All,

My first post here. I've sent my CS2.2 tweeters off to Thiel to be rebuilt since I blew them by using incorrect jumper setting on outboard preamp. In the meantime. I'm looking to re-cap the stock crossovers since they are around 20 years old now. The xover appears has several NP electrolytics being bypassed by 1uF Elcap Polystyrenes/Foil. I guess I have at least two options; 1. Just replacing electrolytics with same value OR 2. Upgrading to some nice film/foil and doing away with the bypasses (except for the parallel 100uF's). Any suggestions? I'm leaning towards just changing out the electrolytics in the spirit of keeping the original design. My plan is not having to go back into these for a while. I tried to attach a pic of the mid/tweeter crossover. Many thanks for any suggestions...

I have the following printed circuit boards for sale:
1 Starving Student board (48 V version) …..$10.00
1 KSA5 power supply board …..$20.00
Sold! Dynahi boards by Kevin Gilmore…..$25.00 pr
Sold! Golden Reference power supply boards by Kevin Gilmore ….$15.00 ea
2 SSR3 power supply boards …..$15.00 ea

$6.00 shipping. If more than 1 board bought, I will combine shipping costs.
PayPal Gift and US shipping only

John Atkinson has measured many ESL's for Stereophile and notes a "hashy" waterfall response.

This looks to affect the highs. I cant say Ive heard it. Does it matter?

Would it be beneficial to cross over to a tweeter/planar/ribbon so the panels are unloaded in the hashy zone
and also to save the amp driving into the low impedance zone.






Modelling of resonating wave modes:

Greetings!

I get spike like pops, when recording my digital piano Casio privia px 1000 trough the output jack and into a USB mixer line input.
What could be the cause? I just got the piano a couple of days ago and i learned this tune and i tested the recording. Excuse the crappy playing it was late at night.

I attached a sample of my garbage playing so you can hear the "spikes" or pops.

Thanks in advance!

A little convoluted, but it could work ... bugfixes, suggestions, improvements, are welcome as always.

Hello This schematic is for an Ashton 60AEA Acoustic amplifier. the impedance is it 100K I think for acoustic preamp guitars.

To make it switchable input impedance between 1 or 1m5 and 100K So An electric guitar can directly in and Also a Guitar with a Piezo and no built in preamp So maybe thinking even 2M

I do not know if the 4558 will tolerate the value changes and the circuit will work with this idea?

Looking at the schematic I would make The alterations to R1, R2, and R9.
Also I noticed on the first channel R8 Is also a 100k resistor to ground before the first gain stage And question whether this should be altered also?

Thankyou for any advice.

Ok since I have both my 6l6 and el34 tube amps running were I want them I'm not on the hunt for a simple but good sounding Phono Preamp . So is it best to run a Phono pre amp tube or soild state with my tube amps???

Hello,

can you help me find a couple of nuts for the binding posts of AR 3A Improved? The original parts would be ideal.. but for the moment I could make it with two nuts.
I live in Italy and it is not easy to source parts sized in inches.
On my caliber the bolt measures 4.20 mm.

Thank you for helping 🙂

Fabrizio

Bought an extra set and never used them.
Paper cone S/N's 404 and 416.
They need some coating to sound smoother. I used C37 on my other pair.

Asking $80 + S&H from CT, USA

NOTE: I am not online every day so there may be a delay in responding.

I am building a KrellClone KSA100-MKII amplifier and need help deciding on the power supply design. When you make recommendations try to keep within the following scope:

1) Overkill - Keep every part with the thought of "over designed" if it says within the chassis dimensions
2) Quality Number One Importance - I am not concerned with the price, I am concerned with the quality of each part
3) Internal Chassis Dimension 258mm W x 143mm H x 358mm D

Does anyone have a schematic to help me choose the correct parts?

What Transformer do you recommend? What are the "perfect" values on the secondaries?

What Capacitors do you recommend?

What Rectifiers do you recommend?

Thanks!😀

I am looking for a Hi-Fi rack component type digital music player. The faceplate item listed here fits the bill, but is not very elegant, even if fixed to a black case.

https://www.thanksbuyer.com/12v-lcd...rt-fm-radio-aux-usb-with-lyrics-display-64325
I am looking for basically a CD- sized box with the touch screen and functions of an mp3 player : I find handheld mp3 players a real nuisance to use for a home system, for example a smart phone which I am using now.

I have attached an image of the Musicolet interface: the basic functions highlighted here are fine, touch screen or button operated. The problem is, this sort of device does not see to exist, unless with expensive SACD players.

I'm about to start a near-field monitor project for my work desk using speaker units from SB acoustics.

The thing is that I don't know much about their units and I would like some recommendations for my project regarding choice of bas/midrange and tweeter along with box topology.

I would like to build an active 2.1 system with some small near-field desk monitors and a 8" sub using DSP to handle my crossovers. My initial idea was to use their Micro C kit as inspiration, but I'm not sure if I should keep it as a reflex box when I have the sub, or build it as a closed box midrange speaker instead.

I find it kind of hard to spot the main differences in sound from some of their units that seems to be similar, except for the choice of membrane materials, what can I expect to be different when choosing a ceramic over a paper or plast membrane?

I'm working on a record lathe that has the feed screw for the cutting head driven by a 12VDC 30RPM gear box motor. The owner wants a PWM motor controller wired in for it. Is there any reason a dedicated SMPS can't be used for the DC input to the controller?

Hello. I have this deck Philips N5371 but i cant find any schematics or service manual for this.Any help?Does anyone have them?

Hello all,

I'm wanting to build my first sub. Due to WAF and room constraints, I'm needing to put it under a couch which is against a wall. There is a total of 11" of height with a butt in the seat, and the bottom is a trapezoidal shape of sorts, see the attached diagram. My receiver has Audyssey XT32 which I'll use for DSP.

I have a budget of $500ish for driver + amp. I don't have either purchased and will gladly buy used equipment.

What are a few drivers I should consider?

Which is a better design in this application, a down-firing 10" or 12", or side/front firing 10"?

If side/front firing, I'd put on a metal grill to avoid the accidental kick.

Thanks for the advice!

My HPamp casing is coming along and I have to make arrangements to ground it with the 0 of the double supply.
I have 2 VHF transmitters nearby , cellphone tower at 800 m and nearby wifi to keep out.
It will be connected to my computer , but the ground of the signal is not the same as the metal outside of the computer case. I don't want to accidentally touch the HP casing against the computer's. Also it will be used on the bed with static electricity , and touching the HP casing is then touching the computer's audio output which I think is bridged. Of course I could spray paint or lacquer the aluminium casing , but that is not easy to do well and
after all the work I put in , I don't want to ruin it soaking it in solvent to get it off again.

So here's my question : Will grounding be affected if I connect it not directly to the 0 , the ground of the supply , but via a 10K to 100K resistor or even a 1M resistor ?
Also do openings for LED's , nylon bolts to connect the LM3x7 to the aluminum case for cooling or even a small plexiglass window for viewing the status LED's inside , affect the shielding much ?

Looking to buy the above-mentioned board.
I'm located in the EU, so I'm open to offers.

Cheers

All the buttons along the top of my reply box are greyed out ans unusable. I only generally need the image one and I can use the attach file for that. But just thought I'd bring this up!

For Sale: B&O CD7000 Player. Works great and has 7pin to RCA adapter. TDA1541A Chip.

Pick up in West Sub of Chicago or ship.

$300

Hi Guys,
Got a Quad QSP (basically a Quad 606,707 in a nicer chassis).
I've taken all the screws out and the feet, which hide another four screws.
I haven't been able to take the bottom of the case off.

Can any one help?

G'Day Everyone,

In a previous post I was asking about experiences with subwoofers to accompany Lynn Olson's Ariel speakers. On that thread someone was asking about my experience with them, so I thought I would start a new thread to answer that question, and hopefully it may be of interest to some of you...

Building the Ariel was not as difficult as I imagined at first. The way I approached the building was to take the time to make a router template for the sides. By using a template you guarantee that both sides have identical rebates for the internal baffling. Even though I have a table saw, I had the board factory cut all the baffling to width (for accuracy). The plans called for beech or birch ply. I had difficulty sourcing this in Australia, so I used marine ply (very expensive!). I built my speakers using a kit from North Creek http://www.northcreekmusic.com/ArielFAQ.html I used the value kit, and mounted the crossover components in the upper portion of the speaker box, behind the transmission lines, with a removable back plate. I will try to attach an image of the plans, as amended by me. A friend of mine borrowed the templates and has built his using an external active crossover. He is pleased wit the result, but I have yet to listen to his pair to compare (he lives in Melbourne, I am just out of Sydney).

I finished the basic cabinets last year, and I am l am pleased with the results. These speakers really shine with vocals/jazz music. With hard rock and large orchestral works the sound is at least as good as my old speakers, but there is not the order of magnitude of improvement that I experienced wit the vocal/jazz/chamber music.

The most difficult part of the construction is what I am doing now: covering them with veneer. I decided to cover them with jarrah veneer using the PVA glue/hot iron technique. I may have done something wrong, but it was a disaster! The veneer blistered and bubbled and looked a mess! I am almost through with the tedious task of slicing the bubbles open, injecting glue underneath and re-clamping. I will post some pics of the finished speakers when they are done.

Here is a link that you have probably seen, but was somewhat useful: http://indigo.ie/~walton/ariel1.html . He does a good job, but I was left wondering, after spending mega dollars on crossover components and valve amp components, spending a few quid on a router would have saved him a whole lot of heartache!

I have driven the speakers with two amps, and old Adcom 555 and an inverted gainclone. I am building a four channel gainclone based on BrianGT’s boards, but have yet to check them out with the Ariels. My aim is to build a tube amp next year, but have yet to decide on topology/tubes. I am in the process of building an active crossover based on the boards by Rod Elliott http://sound.westhost.com/project09.htm

Please note, I have modified the plans that are posted below, they have not been checked or endorsed by the designer Lynn Olson.

Does anyone have experience/ impressions of the Manger Basstuba, found here:

http://www.hm-moreart.de/82.htm

Hi there - I'm thinking of a new project for 2022, and never having owned tube amps I'd like to build something. I've successfully built an Aleph J with help from this group, and think I'm up to building a tube kit. Definitely not interested in flying solo on tubes with a scratch build; need a proven design and kit. Speakers are high sensitivity Zu Omen Def (2x10" full range w/ horn loaded tweeter, rated at 101db 1W/1M, 8 ohm) so I don't need a ton of power. Speakers sound amazing with the Aleph. I'm looking to try the "tube sound" and hoping for more 3D soundstage and "bloom" if that's the right word. Music is wide range, lots of live Grateful Dead, jazz, female vocals. Mix of vinyl and streaming. I'd like to continue to use a pre-amp (currently running a Schiit Freya (solid state) and considering a change to Freya tube or other tube pre in the future)

Right now I'm thinking of maybe the tubes4hifi M-125 monoblocks (http://www.tubes4hifi.com/M125.htm)...but also wondering if I should go for a 300b like the Elekit TU-8600. Obviously these are at sort of opposite ends of the tube spectrum...what do you think I should do and why? Budget should be in the $2-2,500 range but flexible.

Received it in December. Untouched except to verify values in parts, etc. And completeness. I decide not to go ahead with it.
$90 plus usps priority mail which would be around $10…
Thanks

So I finally scored an “awesome to me” Orion amp pretty cheap, for my own personal use, which I’m really stoked about cuz I couldn’t/wouldn’t drop retail $$$ on it with my current budget 😅 and it only had 2 blown PS mosfets on last bank. It took a rough ride via USPS but nothing was damaged or came loose even, just a hard knock to main body and side panels bent to ****, which I already straightened out, it was like it was literally thrown while it was stuck in Indianapolis USPS for 4 days ...

So to start I removed all PowerSuppy & Output FETs and both Rectifiers, booted up to get an initial probing, booted right up pulling only .06 amps in idle, not in protect.

Square wave on each of the PowerSupply Gate @ 22khz.

I see no waves or voltage over 1v on any of the OutPut or Rectifier pads.

I see ?sawtooth/triangle? waves & square waves on the SG3525AP.

There’s 2x LM393 MICs to the right of the 3525, I see various voltages ranging from 1v-12v but no waves on each, the voltages are not the same on each pin, I have them written down.

The IR2110S on output riser card has pins 11&3 + 7&10 shorted off/on board, and shows barely a volt on each pin, same with the LM393 next to it, barely a volt on each pin and neither have any waves, of course right since nothing is getting proper voltage?

So I checked the pins leading up to output card (a set of 4 at each corner) none have over 1v on them, there looks to be a voltage regulator, IRFBC30 above the transformer that’s above the riser card with a heat sink attached to it, barely a volt on each leg.

I’m new to this amp/board/design, I don’t know how it exactly works, if it needs PowerSupply to be working to show signals/voltage on the output section or not or if it needs a signal via RCAs, etc. I have ordered the last 2 IRFP4868 @ Mouser (every other vendor in the USA seems to be out, even eBay) I wanted 8 new matched PS FETs but got 2 so I can at least test it with the other 6 that tested good and within similar spec, I also ordered 6 new matched IRFP1405 for the Output section even tho they tested good and are all within similar spec as there seemed to be some molten backs, getting worse from 1 to 6, with 6 actually having blackened TIM near it too, you can see how bad it is in pic, will not sit flat against heat sink now.

All the FETs had those MESHA type solder shims but none were soldered on, just TIM used. I have TO-247 size blue thermal pads and high quality TIM I can use instead if need be, but ya that’s the jist of it right now, worried there’s multiple damaged pieces from rough shipping ride and/or from PS blowout cuz so many of the same ICs have different readings, there’s like 5x TL027 as well that all read different diode check wise that don’t seem to be on same trace and/or same resistor. O thing else test bad diode wise. I may be posting this early as I don’t have the FETs to get the Power Supply section up and running yet to test section by section, I also don’t know if and what it needs PS/Output/Signal wise to even be able to test each section so hoping someone with Orion XTR experience can advise.

This is a “stay in my collection forever and run ‘til I finally get an HCCA” amp. I know that don’t really matter but I’m excited to get one in finally as Orion is my fav besides Alpine, hoping the repair isn’t crazy cuz I’ve heard that the output card/section can be a nightmare even for experienced techs ...so I’m def approaching this cautiously wanting to confirm working sections by sections before soldering in $30-$50 FET sets. Any help greatly appreciated, ty 🖖🏼

I have a project build here

https://www.diyaudio.com/community/threads/instruments-amp-y4-trio.383281/
While learning to make custom filters and eq for this, I had a moment of ponderings and came up with this. It could be drivel for all I know as I am still taking baby steps with electronics. Please point out the holes in my understanding if you find this of interest

Learning how filters and tones are configured raises another question. I don't think it's only eq'ing of particular frequencies that shape sound. From careful listening to the harmonics (am I using this term correctly? Please educate) produced around each fret and how that fret is played, I have come to the belief that to shape sound from an instrument;

1 - multiple bands of eq in the relevant area of the instrument, at least 4 bands for a bass instrument. I think apart from the level pot, this is the first shape step to shape a frequency curve, but this doesn't alter the "voice"

2 - each band should have two parallel circuits that are more complex and contain a high pass to one side and low pass to the other. These two adjacent circuits need level pot, range pot, delay pot and reverb pot. The "voice" circuits to then mix back into the that tone bands output

This is the only way I can see to truly shape a bass guitar "voice" with analog. So each tone band consists of tone knob, upper harmonics level and reverb and lower harmonics level and reverb. My own voice is fairly low to where a lot comes from the subwoofer too. I can "shake" and add inflections while singing to suit the moods of different songs. Indian music composer R.D. Burman had his own unique singing style that he distorted with gargling type sounds at various reaches. With this, I infer that a distortion level on each of that three parallel circuits per band will do a job too

Basically this means that each band of the tone controls get 9 knobs or so. This is just my thots from what, I don't know whether it's on to something or coming from ignorance. After I finish the amp/cab to a usable level, I am going to seriously learn to implement this. I haven't seen it done like this before and if I am the first one to think of this break down then I would enjoy it to be known after me as the "Bassinga" (bass singer) system. If it's already old news to split each band and adjust harmonics individually like this, then I hope someone points it out

Click to expand...

Hey. Fellow true music audio nirvana hifi seeking dudes. 🙂

The term ”burn in” signal simply reaks of bullcrap and old snake oil.

Wellz.

Play this on your system. 10 hours. High volume. Not insane, just medium high. To get them tweeters, midranges, and multiple large woofers to soften up.

Get them to effortlessly reveal the mcrodetails. The warm and juicy details. The powerful room and sofa shaking firm and powerful bass. And sub bass.

The class A Pass Sound 🙂

Do it!
A serious listening test whitout a 24 h warmup is not a serious listening test?

Do the mnimum 10 hour pink noice system stretch and warmup. Do you hear a clear improvement?

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Hi,

I have a fully finished F6 for sale. One of the most universal diy FW amps if you ask me. Selling it because I desperately want to finish other long going projects and need some cash to push it. As you can see on the photos it is a very clean built (I have a bit of old about it so clean solder joints, all flux washed off, parts aligned etc 🙂. It uses a bit bigger 5U 300mm chassis I got from Italy. PSU uses Primrose audio grade 400VA transformer. As you can see all wiring done with the connectors so you can later on put another FW boards into it if you want (sorry no pre tapped holes though). If you have any questions, please ask. Price is $1000 + PP fees + only US shipping (maybe it is not even at cost nowadays with all the prices went up). Thanks for looking!

hi all - is this

ferro fluid leakage and why does it happen​

I'm building a stereo amplifier, my first ever build. It will be a dual-mono design.

This amplifier will be based on the carcass of an old , broken, Adcom GFA-2535. I have discarded everything except the two hefty transformers (center tap) which supply 35V to their secondaries. There will be two power supply sections, each with 40,000uf filtration. The two amplifier sections will be MOSFET kits I purchased from AMPSLAB. 60W per channel. Everything goes back into the original ADCOM case.

I am also installing soft-start modules. One for each channel. These are the relay type. I purchased the bare boards from that auction site. They are USA designed and manufactured. I now have built and tested the boards.

Here is my idea. I would like to keep the existing wiring harness that supplies 120V to the transformer primaries intact (as is). Can I connect the soft-start modules to the 35V secondaries, ahead of the rectification boards? I'd appreciate your thoughts. I'm sure there are some good reasons not to do this but to me, it seems like it shouldn't make a whole lot of difference. And it would make wiring a little simpler (I think).

Hello,

I have several sets of Boston VR-M 2-way speakers. A couple M60 and a couple M50. These are identical except five of cabinet and driver. Each has dual sets of posts for bi-amp/bi-wire with the connection pieces for using single wire.

On a couple of them (one of each size) there is no longer any low end sound. Whether the connection piece is in place as usual or not (and connecting wire to the lower end posts only) there is no low end.

Where do I start to diagnose this problem? What is the likely culprit?

Thanks

I'm interested in cloning a pair of Eico HF-22 monoblocks, as I think the Mullard style of topology will be a little more forgiving in terms of transformer selection. I'm interested in using the 50 watt ultralinear OPT's sold on Ebay by a Greek company calling itself Thermionic Labs. They seem very high quality, run a little over 3 Benjamins for a pair, and the specs seem right on, with 6k6 primary impedance and 43% UL taps. I'm curious if anyone has ever used their product, or any others I might consider first. Also, I would love to hear any other advice from folks who have been down this road before. I plan on triode-strapping the EF86 tube

Hi guys, please go easy as this is my second build and I'm still a bit dyslexic with regards the primary and secondary wiring basics. I'm confident with safe IEC wiring and the on/off switch but lost on the power supply board wire colours.

In the pic attached what colours do I put in 1 2 3 4 on the power board module?
(I've just positioned it like that for ease of viewing)

Thanks in advance for anyone with the knowledge and patience to help.

Also please ignore the two small bottom green circuit boards as these I don't want, so just imagine the pic with the tranny wires all loose.

Hi all. I'm triying to bring back to life this old player. AZ6801, philips. 1989.
When I got it, it don't power up. I find fast why. The power regulator, which output 5v for the microcontroller, was bad, and in their out pin, it has 7,8v.
I change it for a 7805, and bingo, display began to works, and i saw the pattern that this player shows at boot, before do focus or anything more.
Other failure, was a TDA7072 burned, and now its changed also.
Ok, now, it powers up, but do nothing. ONLY moves the pickup to the initial position, and thats all.
Laser dont lit, Cd dont spins...
If I force láser on, cheating the APC circuit, it works and goes on. But, if i play with the levels of the door switch, and pickup initial position swicht, microcontroler dont mind, and no lits the láser nor try to focus.
When I test the original damaged regulator, i saw overvoltage in his output. It must be 5 v, but was giving 7,8, and, since it powers the microcontroller, i think that this overvoltage could fríed the controller.
But, hey, as i've said, the controller works well the display and positions the pickup in the initial position, from there, now it must power the láser, and do the focus search., but dont do anything more. So, is not died.
Thats all. What do You thing? Damaged brain? I'm losting something? I accept gratefully any help or thinking.
Marry Christian, and all the Best from Spain.
Albert.

Hello everyone,
I have a problem again and I'd like to address all those who keep the forum alive.
I have purchased a Rohde & Schwarz UPD. Unfortunately the box does not do what it should.

When I switch it on, the monitor turns white and it starts beeping.
That's it. The device was supposedly still working at the seller.
I have a UPL, that's it, turn it on, screen white, then the screen turns black and the routine runs like Dos Computer. Then a VGA graphic builds up and there the UPL is working.

Unfortunately the device is not yet with me because I live in Taiwan. But in 10 - 15 days it will arrive here.
What am I looking for!
Who has had something like this before or believes to know what it could be.
I search for
1. the service documents volume 1 and 2.
2. an operation instruction operator manual
3. the hard disk software

And a thousand good advices.

With kind regards
Johnny from Taiwan
jdl.taiwan

I’m working on a Soundstream BXA1-10000D

The rail caps are vented .

They are 2200uf 100 volt .

The issue is I cannot find the caps anywhere the originals are 25mmx30mm

I can find 25mm diameter but the height is the issue all the caps I’ve searched are way to tall and the bottom cover will not go back on .

Any ideas on what to do ?

Just saying hello. I am an active AV geek. Occasionally tinker with speaker rebuilds and experimental systems. Have 3 separate systems (party, movie, music) and lots of "spare" equipment lying around. Take care all nice to be here!

Hi,

I have just bought for good price (i know why now) audio physic tempo 2. I had no chance to listen them before buying - these specific speakers. First thing I noticed was lack of bass but I found reason - very poor soldering. High tones were ok, but something happened during soldering and now one of tweeters sounds quieter.

I will check tweeters soldering too, but in the mean time I got this idea to check what kind of tweeter is in them and if neccesary replace them, but I can't find any reliable information.

Do you maybe know what exact speakers are in Tempo 2 - both of them.

Hi, I found in my old documents a paper about construction figures for the Dynaudio Xennon 2 kit ( two-way speaker with 24W75 and D28AF). I scanned it for the community. The quality is not perfect but nevertheless readable. If necessary, PM for more details.

I tried to search for my bookmarks and found only one I recently bookmarked, all the others are gone it seems, or what happened to them?

Edit:
It seems I must have mixed up the difference between Bookmarks and the "Watched" on the menu bar where the latter is sort of misleading as I thought "Watched" was a new feature on this forum keeping some kind of log of all threads I have ever watched, checking out "Watched" I just see a very long list of unsorted threads page after page and had no idea what I was looking at as it didn't resemble my neatly arranged and named folders.

It seems like bookmarks are a tool for saving a single post although it works for following a thread too, while the "Watch" is another type of bookmark sort of but only for a whole thread, if I got this right.

The poor thing is, those Watch-marks are now unsorted in random order without any tag/label/folder, and having over couple of hundreds of unsorted threads it's really difficult to find threads let alone remember why a thread was saved as I had lots of different folders for various topics I earlier saved under such as "Resistors", "Capacitors" etc., now it's near unmanageable and useless, terrible.

Will we have a folder option or some other way adding labels/tags for our "Watched" threads in the future, and, are the old folders stored somewhere and can/will they be restored at some point later?

Can anyone confirm or reject the impression I am getting? I have two circuit boards (in inverter welders) with malfunctions, and each unfortunately has an MCU. All diagnostic procedures (tracing and checking signal paths) lead me to pins of 64 or 44 (respectively) pin MCUs.
I am thwarted by my inability to know what signals I ought to see at these most of these pins (apart from power supply and earth pins) because their functions are programmed into the MCU by the equipment manufacturer.
My hope was that it is possible to download out of the MCU its programme and work out what should be happening, but my Google searches suggest to me that this is in practice impossible.
How do we use the diagnostic skills and techniques we have managed with for years on all sorts of circuit boards if there is this impenetrable device on the board?
To illustrate the difficulty, one of the welders (TIG process) only activates its HF (which is supposed to initiate the welding arc) for a very brief pulse, whereas is should persist until the arc is established. This pulse emanates from the MCU, which should be responding to something either sensing the drop in voltage as the arc establishes, or the presence of an arc current. Both are sensed and their signal paths lead in plausibly fault-free ways to the MCU, but without knowing just what the MCU is supposed to expect before halting the HF, I do not see what to investigate. For all I know, it might be sensing some entirely different fault condition, and halting the HF as a protection measure. But how does one proceed logically?
Any thoughts?

I am in search of a three way SQ car audio system. I have not had anything but an OEM system since 1985. I have considered a DSP and 4 channel class AB channel front end with a class D sub amp. My budget is $1k or less for amplification and DSP.

I presently have Dayton AMT Pod4 tweeters, Dayton RS 100-4" fullrange, Dayton RS 180P-7" midwoofer, and Dayton RSS265HO-4 subwoofer.

My Idea is to run the 4" full-range from 300Hz and up off of front channels. Then rolling it off at about 5kHz at 6db, and setting high pass close to that point with single cap.

I want to drive this system with a DSP that is capable of HD at 32 bit 192kHz. But finding such a unit that will fit my budget is not easy.
I am wondering if there are SQ units available that I can afford.

The only DSP unit that fullfills my cost and capability requirements that I have found is the Cadence DSP4.8. There were some negative comments made about noise and quality issues on the internet. So, that makes me skeptical.
As far as amplification is concerned. I am considering the Sundown Audio SAX 100.4 V2 class AB. And one of the new Sundown SFB-1500D or SFB-2000D class D sub amps when they come available.
Any insight and suggestions will be helpful and appreciated.

If I had the funds, I would go all top of the line Zapco. But!!!!

Here is an article I put together about how to deploy proper power supply bypassing capacitors to op amps and split supply circuits.

Types / values / dielectrics / and voltage coefficients are all discussed. What do you guys think? Agree? Disagree? Looking for any feedback or insights that were maybe not mentioned or touched on. Here is the article -

https://sparkoslabs.com/power-supply-decoupling-capacitors/

How do you delete PM?

Art

Hi All!
I am currently designing a Class D Amp based on TIs TAS5504 and TAS5152. I use the TAS5152 in 2x BTL configuration with 2x 10uH and 1x 0.47uF for each BTL. PVdd is 36V

So far it's working, but most of the coils I tested for the output filter heat up for 20-30°C above Tamb in idle (!) mode.
And those Coils are listed as "Coils for Class-D Amps". So I guess the resonant frequency of the core shouldnt be a question.
But to check it: (1) what should be the resonance frequency of the core when switching is done at 384kHz?

Interesting is that the coils do not heat up that strong when I place them in the TI eval-Board. So (2) my layout could be a reason? (I have a very compact board)
Or could there be some jitter on the PWM caused by a decoupling failure? (3).
I measure betweeen 0.5-1.0V Vss ripple at 384kHz. This seems to be a normal value to me (which was also confirmed by a Spice simulation).

Any help, hints or notes would be highly appreciated!

Thx and best regards,
Klaus!


P.S.: I foud the "heating in inductor thread", but this ended in nowhere 🙁

I have been reading the forums, and the word "servo" keeps

poping up, I must have fell asleep when that topic was covered,

or I learned it by another name. I have been reading the "op amp

book", I have attached a small quote from chapter 1. Op amps

are very important, and I want to eliminate any confusion I may

have, please explain the servo circuit.

Thank You......

After much reading and internal debate I am going to try the following SSE build


Power - Antek AS-2T350 (350-0-350)

Ouput - Edcor GXSE15-8-5K
Rectifier - solid state only


Tubes - JJ EL34L
Choke - Triad C-14X
Motor Run Cap - Pingcon CBB65A 100uf 450VAC


All other parts per standard BOM published on the Tubelab website. I do have a range of cathode resistors from 470 - 680 ohm at hand if need be.



I am very much new to this so will have many questions as I go along. First question of course does any of my choices present issues that will require solutions outside the standard build documentation? I decided to not follow the most standard build by using a toroidal power transformer and opting for ss rectification just because it appealed to me. End goal is to have an amp that will push my 4" full rangers from 80hz and up.

I haven't measured a full set of polars from horns for quite a while. I think the last time I did measure I rotated the horn at its mouth (point B in the image) for the measurements.
Over the years I have read some people rotating at the throat end of the horn.

Which is correct ? (where do you rotate if you have a speaker with direct radiator bass units and a horn loaded mid/tweeter ?)

Thanks,
Rob.

Dear Members,

I'm wondering if the huge capacitance of supercapacitors could be any good for DIY audio amplifiers in linear PSU-s. I know a voltage stabilizer (e.g. LM317T) already has a good PSRR (power supply ripple rejection) but how about using 1-2 supercapacitor(s) after the usual bridge rectification ? With current limiting of course to protect diodes (depending of type of course), that little bit of extra charging time is no problem, the main amp circuit is switched after PSU measured OK by the microcontroller anyway.

What do you think ? Has anyone done such a design ? I could also imagine 1-2 supercap(s) and then normal usual "chain" of caps like normal (low-ESR) electrolytes and finally the film ones on top of them. This way "speed" would be assured too, at least this is what I think.

Any advice, pro, cons, thoughts ?
I'm not a pro in electronics so I thank you for your patience 😉

Hi all,

after reading about open baffle designs and projects across the internet for several weeks I am coming closer to an idea what I would like to build myself.
Sine I have only built a few diy kits myself decades ago I hope I get some help in designing my speakers. I do not have any experience with that so far.

Inspirations came from: the pure audio project, spatial audio, GR research, blue plane acoustic, supravox and others.
My first idea was to go for 2* 15" woofer + wideband driver (e.g. Tangband...) but I have changed directions.

My idea is to go for a 3-way system using an AMT as tweeter. Soomething similar to the Spatial Europe mc series no 8: https://spatialeurope.de/portfolio-item/mc-series-no-8-en/

I dont want to play around with DSP or equalizers, I hope to get good results with just passive XO.
My first choice of drivers would be Supravox 215 (or maybe 165) for the mids, a Mundorf AMT (AMT23D6.1-R) with homemade waveguide. A reference design on the Supravox homepage suggest th 285 as woofer but I wonder if there is a good combination utilizing a 15" such as the Spatial Europe speaker.
I also looked into Acoustic Elegance drivers but hesitate because of the very high shipping costs to Switzerland where I live.

On further "requirement" is moderate baflle size, again the Spatial Europe mc no 8 would be just right, as well as the reference design on the Supravox homepage. The intention is that it should not dominate the living room, so about 45x120 cm is on the upper end of acceptable sizes.

For the beginning I hope to get some advice on finding matching speaker drivers, I have set myself a budget of max. 1500 EUR/CHF for drivers per speaker.

Open for inputs! I know that some software exists to simulate different speaker positions and baffle geometries, I plan to do some experiments with these software packages to better understand the implications different options....