Has someone the PDF and Excel from Vinyl engine and can send it to me via PM?
I lost my account and can not re-register as it is closed actually.

Thank you in advance

Hey guys,

I just wondered if there are discrete topologies to make active filters like Linkwitz-Riley lowpass or -highpass filters without op-amps?
As far as I see, all you need is a non-inverting buffer. I am not at all familiar with discrete designs.
If there is nothing like this: Are their discrete op-amp designs which can be used with single supply?

Best wishes,
Dennis

Hi guys, Good day!

anyone can help me i need schematic diagram of SMP400A180 please.

Thank you guys!

This project started few months ago when I found a nice R-core transformer in a pile of electro junk at the local flea-market (60V CT secondary, 200VA). With such a voltage/power rating the logical choice was 2 x 50W AB class amp. Lateral MOSFETs (connected as Source followers) were chosen as output devices this time too.

The input stage needs to provide more gain than in Cubie2 so I chose BA3-like topology with cascoded JFETs and current mirror load on them. Q5/Q8 still make a base-driven transconductance gain stage which enables GFB/NoGFB games. I chose the loop.

Vbe multiplier (Q13,R20,P1) should not be in touch with the heatsink (Laterals know how to take care of themselves), its only job is to keep the Vgs (and Id consequently) of the output stage at fixed value no matter what are the temperature/current conditions on BJTs but it can be replaced with LED or any other Vref of your choice (for Id of 200mA I need total OS Vgs of 1,3V which roughly equals the voltage drop on two 1N4148 diodes connected in series).

The current through Q1,Q2,Q9,Q12,Q3,Q6 will depend on JFETs' Idss and it can be anything from 3 to 10 mA. The current through Q4,Q5,Q7,Q8 shouldn't be higher than 4-5mA and it can be set with value of R4,R6 (the higher their value, the lower the current - and vice versa).

P1 sets the Iq in the output stage (my heatsinks can't take more than 200mA per channel comfortably, but you can go as high as your heatsinks permit you - you'll have wider cl. A regime) and the P2 sets the DC offset at the output - start adjusting with both pots at half of their value.
The gain of the amp is about 23dB, but it can be altered by simmetricaly changing the R13/R14 and R11/R22. C1,C2 will allow for about 100kHz bandwidth.

Signal-ground and power-ground are led to star-ground by separate wires.

Final result sounded good enough to retire the excellent Cubie2 (all the finesse is stil there but Cubie3 wins when it gets loud).

Hi Guys, I am looking for one or a pair of Infinity 902 5137 woofers. I am based in Portugal.

As far as I know they were used in the Infinity Reference 40,50 and 60.

Thanks

Hi everyone,

I am writing today to ask for help or ask about measuring the thiele small parameters of a stud with the LIMP software from ARTAlabs.


I have been trying to measure the thiele small parameters of my hearing aids for 1 year now, and I can't find any document, any video, anything that clearly explains how to measure them, or if it explains it well, it's out of my hands how to measure them. do it.

The method that has caught my attention the most has been LIMP, since it is to make some simple connections, and use the software, the thing is that I do not understand the connections that I have to make, and the manuals and videos are not clear neither. (in my opinion)


I've tried to make this circuit:



But the connections of the "Phone" output are not clear. I don't understand if I have to remove the right or left channel from the "Phone" output or both... And what I understand, and I can do, I don't know where to connect it on my laptop, or on my PC.

I have looked for videos that tell you how to do it, but there are only people who connect it to their external audio card, and with many cables that I don't know where they come from, since they are not in the diagram.

So, I would be very happy if someone could clearly explain to me how to measure my speakers, so I could finally move forward with my home audio system project.

Thanks in advance,
Radew.

Im not sure how to connect an standby switch to Mornsun lof550-20b48.
+5V and GND?
https://www.mornsun-power.com/html/pdf/LOF550-20B48.html

Dear friends
God bless you all
Many thanks to one of the forum member who help me a lot to improve and upgrade my mark levinson gear.
However I came to a little conflict and all of you who experienced different capacitors in a circuit can give a good advice
In all the old mark levinson the capacitors are not part of the signal path but a reservoir for it's power supply.
However in the 32 preamp mark levinson chooses to work with sanyo os-con polymer capacitors which known for its very high ripple current and very low esr.
I have recap those os-con by nichicon polymer the sound is super dynamic and full of energy but less articulate and refined.
I have tried to replace those nichicon by electrolytic capacitors panasonic FS which always gave me very good sound.
With the panasonic the sound became refined and articulate but far less dynamic, less bass impact and less slam.
Now here is the question since electrolytic are better than polymer by its leakage current, why not using hybrid capacitors which have all the benefits of polymer and all the benefits of electrolytic ???

Did anyone experience with hybrid vs electrolytic
Or hybrid vs polymer ???

Many thanks for any reply
I wish you all happy new year

Genuine Toshiba 2sa970bl /2sc2240bl pair
Hfe around 450-550
Matched pair 6usd
Unmatched pair 3usd (2sa970 is around 50 higher than 2sc2240)
Shipping 15usd with tracking number
PayPal + pp fee or ff option
Or Revolute recommended

I gathered for HPA-1 clone.

I finally finished the SIT NFET NFET MUFF Mutant Power Amplifier. The initial ideas for this design were discussed in the thread https://www.diyaudio.com/community/threads/pimping-papas-sit-muffs.392149/post-7172622.

The output stage is based on the last schematic in the Nelson Pass paper “BAF 2022 SIT Power Amplifiers” https://www.diyaudio.com/community/attachments/baf-2022-sit-amplifiers-pdf.1101782/, shown in the first image below.

The front end gain stage is based of the "New Stasis Front End" described in https://www.diyaudio.com/community/threads/new-stasis-front-end.363701/, but has been simplified. My PCB for the front end has more "features" than shown in the simplified schematic below, which I will explain later posts.

AS BUILT SPECIFICATIONS:

Inputs: single-ended RCA or XLR balanced
Input impedance: 10k
Gain: 20dB
Distortion @1 watt: 0.12% (without feedback)
Damping Factor: 90 (without feedback)
Output power 8 ohms: 50W
Output power 4 ohms: 30W
Output Noise level: 100uV or below.
Power consumption: 330 watts

Output Stage Power:
75V power supply
70V rail voltage (5V lost due to capacitor multiplier noise filter)
2A bias current per channel

Front End Power:
2 x 36V switching mode power supplies (SMPS)

Hi Everyone,
I hope that by creating this account, I can add something back to the DIY community.
My experience: I have (re)build three speakers, to only mediocre success... It's hard and the more you learn, the harder it seems.
I also have experience repairing amps, which was a bit more successful.

Kind regards,

Hi All,

looking für the schematics for the SAE-MK3-CM power amp, where I can read the values of the caps and resistors.
Will be nice to get a good one.......

regards
HP

So I am gonna build a garage, and have a 12” sub that is going in it. I plan to bury the transmission line under the concrete, and run the entire span of this garage.

Now the question: Can the t line be divided? (Think vents, but instead of one section that equals the t line, we take the section, divide it into 2 or more “vents” and that equals the section as a whole)

My sub is 25hz, and 85 sq in for sd.

I was thinking 4 separate sections to equal the full wave length “instead of quarter wave”

Will this work?

I was fortunate enough to get an Advance Acoustic x-i90 because it has a fault.
The amplifier works if I connect the audio source to AMP IN.
But if I try the other inputs, I get no sound output.
All the functions on the front panel seem to work as normal.

https://www.easylounge.com/amplificateur-hifi/advance-acoustic-x-i90-noir-52374


Hard to search for errors without the schematic (have sent an e-mail to Advane Acoustic, but no response yet)

HCF4052BE is used for input select - seems to work fine

There is an JRC4558D op amp where I do not find any signal, so this may be the reason? Have placed an order for a new one to test
Any one else with this problem? Or any one have the schematics to share?

I am planning to build a single channel dipole subwoofer system that will combine two U-frame subwoofers in a mirror pair (facing each other). I would like to model the far-field response of the system but am not sure what programs could be used to do this without first measuring data, e.g. SPL at front and rear. If I had measurement data I could do the far-field modeling myself. The problem is I want to run some "what-if" modeling scenarios and see what each looks like BEFORE I build. I would like to investigate the relative position and orientation of the two U-frames, as well as the effect of tapering the tunnel to a smaller final opening compared to the driver end. Not sure I can do these thing in e.g. Hornresp or VituixCAD.

If you know of a program that can be used to model multiple independent but identical sources like this, please let me know!

I would also love to collaborate on a design with someone who is knowledgeable in the software or own some commercial software that can do such modeling.

Thanks!

Have some Alephj monoblocks.
I did not build them.
Wondering if it is possible to use all of the psu etc and try different designs in the same case, removing the aleph j boards.
The m2x look a similar size,and curious about what will fit.
Any help would be appreciated.

I have this from Ali, tempted by galvanic isolation and canel swap in DSD. But it is not working. Any ideas ?

I'm looking for 6S31B-R miniature tubes.
To buy or swap; I have lots of nos tubes to trade in.

Does anyone have any documentation for the ABEC project/Script import in Akabak?

I'm looking at importing into Akabak directly from Grasshopper

Hi, I worked with repairing hi-fi equipment and TVs about 25 years ago. Now, I enjoy it as a hobby.
I do design work, build stuff and try to repair stuff

I'm thinking about project for 2025 and would like to build a small 2 way with the 5FE120 which seems popular. They're made in Italy which is appealing to me considering so much European manufacturing has moved to Asia. Its intriguing how Faital has managed to manufacture a well regarded driver at such a low cost in Europe. This has got me thinking can i match it with another budget friendly European made tweeter that performs well?

I am thinking about a living space friendly solution with basically 2-way floorstanders together with a sort of 10" bass sections but mounted in a dropped ceiling. My initial assumption is I'do a wooden closed box that I would finish outside nicely to act as dropped ceiling. I would mount the ceiling more less aorund the floorstanders location so that the distances to the listener are approx. the same. The bass section would be crossed steep at ca 200Hz. In this way I hope to create a sort of virtual stereo speaker pair. It seems a nice idea to me but it rarely appears on the net and maybe there are good reasons for that ? Does it have some important drawbacks compared to 1) integrated bass sections in the same enclosure (except the obious co-location that should not be a big factor for a <600Hz range) 2) a standalone subwoofer located somewhere on the floor ?
And a second question - if the idea is more less acoustically sensible then assumed the dropped ceiling will be adjacent to one longer wall is it better to locate the driver closer to the wall or possibly on the far end of the dropped ceiling and why/how to estimate the effects ?

Gday guys,

May I please ask for some opinions.

I would like a dual channel variable power supply. Mostly for initial testing of projects.

I already have a 0-18vdc single channel supply.

I would like to have the flexibility of up to say +/- 60vdc for testing things like a future wolverine build.

I could fairly easily make a variable regulated supply for +/-25vdc or so /1.5a. Not much use for testing power amps though. A very cheap option but limited in usefulness to smaller amps and linestage type things.

I could plausibly, with a lot of work make a +/- 60vdc regulated supply but this wouldn't be easy nor cheap.

I could buy a variable supply such as the nicepower sps605-2kd 2x60v @ 5a. Which does most everything one might want for circa $300.

Or for similar money I could buy a variac and cobble together some spare parts and meters to make a variable linear supply with the added bonus of being able to test 'finished' amps as well as modules.

Should I just grab the variac?

Setting gain on sub amp. Everything flat off , Hu amp same etc . Hu 2/3 volume running a 50 hz test tone gain turned to minimum . Using Bluetooth for test tone .
Problem as soon as I turn on the test tone my subs it sounds like to me are playing. The tone really loud before I set gain. Really can't even turn Hu up to 2/3 it's too loud . Getting 13.4 from battery 13 .2 from remote wire. Can not touch gain at all . When I played music with minimal gain the bass sounds like it's coming from the car behind me , not up front under me so to speak . Triple checked my grounds, RCA's, different Subs .

Just researching now. Anyone tried this?
- http://www.geofex.com/Article_Folders/mosfet_folly/mosfetfolly.htm



A power MOSFET driver for an output tube.

Moreover - an Op-amp driving the MOSFET.
Op-amp as a preamp (for a SE amp) and as a phase inverter (for a PP amp).

Hello, I'm new to the forum. I'm studying mechanical engineering and looking to learn more about electronics. I have almost no practical experience with electronics so far but I know a lot of the theory/equations from my classes.

I'm interested in learning about Hi-Fi audio, guitar amps and pedals, and especially tube audio. I'm currently trying to build a tube preamp for my Hi-Fi setup as well as some guitar pedals.

Haven't read your always valuable, helpful and substantiated contributions for almost six months. Hope you're ok, JMFahey of Argentina?

Best regards!

As pictured.

Set for 70V rails.
1st GB boards with NFB trace mod.
10k input impedance.
Outputs NJW1302/3281 Hfe matched within 0.5% and 5% between NPN/PNP.
Drivers Sanken 4883A/1859A HFE matched.
Predrivers KSC3503E/KSA1381E HFE matched.
Q1/Q2 Q3/Q4 Q5/Q6 LTP transistors HFE and Vbe matched, 0.1% H8 resistors in the LTP.
VAS KSC3503E. All other toshibas.

Surplus to requirements - I have 6 wolverine channels at the moment so these to a good home!

------------SOLD --------

and I'll cover 50USD of shipping worldwide (buyer pay extra over) from NZ (would likely make it free for NZ/AUS).

I have a pair of old speaker cabinets - they are quite nice. The drivers are broken so I would like to replace them. I would appreciate any pointers for driver/tweeter pairs, speaker-driver simulators, and cross over simulators or pointers. The mid-base box is ported - complicating driver selection. I'm a beginner but versed in some engineering so I might understand a spec but not know its relative importance. I have a Apple Mac for running simulations.

Any help is appreciated. If I missed a post that has all this, I'm sorry, and would appreciate being told where to go (no pun intended).

The speaker cabinet:

• tweeter is mounted in a free standing way allowing a maximum face dimension of 4" x 4" (102 x 102mm)
• mid-bass driver is in a box with internal dimensions of 16" x 8" x 10 1/8" (406 x 203 x 257mm) or 0.748 cu ft (21.2 Liters)
• the box is ported with a 2" ID (50.8 mm) pipe running 3.3" (83.8mm) into the internal space and through 3/4" (19.0mm) of cabinet.
• the port is pointed downward and the box is suspended in the speaker frame to allow air to flow freely to and from the port
• the mid-bass driver is mounted on the 16 x 8 face and has a 5 3/4" (146mm) hole center horizontally and 7" (177.8mm) down from the top
• the box contains 2" of insulation material against the wall opposite the driver.
• what I think I need of a mid-bass driver: Fs = 40-50Hz, Qts = 0.35-0.45, Vas = 0.52-0.88 cu ft (15-25 L)
• my hope is to have a very accurate/neutral speaker with average or better off-axis listening.

One of the more important specs above is the hole already made for the old mid-bass driver. I want the new driver to fit that. I can, optionally, pair the speakers with a sub.
I plan to build the crossovers if they become too pricey. I would like to keep the drivers(2)/tweeter(2) budget under $400. The amplifier to drive the speaker is a fairly clean 125 W/channel into 8 ohms, class D that will drive 4 ohms without an issue.

Thank you.

Hi,

I recently bought some of these and upon initial listening I ws pleasantly surprised at the quality of sound coming from these things.

Ok, no bass, but still....

After more extended listening, I find I notice the HF peak noticable, slightly over crisp.

So I knocked together a very rough RLC notch with almost no maths, and I think it is an improvement.

Edit: reviewing the datasheet again, I have centred about 13k not 8k, assuming I did anything right.

0.33mH, 0.47uF and 3R3 by the way.

I'mlooking for alternate experience with these drivers from others.

Did you employ a notch filter? What values did you use? (I might be way off...)

I'm thinking that these may form the mid HF for a FAST/WAW, low XO 2 way, design.

So really anything could be useful to me!

TIA

Hello
Im New in this forum.
To present myself. Im interested in sound, food, electronics, filterconstruction, guitarplaying and art. and and and......
I have got a bad habbit (according to my wife) refurbing speakers from 70 and 80.
Last project was to bring a pair of Tannoy Lynx back ti life. It endet up as a succes for me.
Further more im building guitar stompboxes, tube preamps and so on.
I want to join the company for inspiration and help.

regards
lauge

Howdy folks! I just purchased a Rose RS-150b streamer. As for now, I have to use my Pioneer Spec-1 preamp while my McIntosh c-28 is being pro restored now. I have the Spec-1 controlling my MC-7270 power amp. The Rose RS-150b streamer has 10 pre-out level settings ranging from 100mv, all the way up to 5000mv’s. They say that in order not to damage your equipment, you mustn’t put the mv output too high. If there is anyone who is familiar with this RS-150b, please let me know which mv is safe to use.
Happy holidays to all and yours.

I have a large number of Caddock MK232-50.0K-1% thick film resistors.

On Digikey they retail for $6.62 each + Tax + shipping.

My price:
1 piece = $5 (US shipping included)
5 pieces = $20 (US shipping included)
20 pieces = $70 (US shipping included)

I just love big, old power amps! And now I'm considering buying a model 4000 Threshold amp that is for sale. The look of this class A amp is fantastic, I can imagine the sound is too. But, there is very little information on the specs on this amp. My biggest concern is how well it can handle low impedance loads, since I will be using it on a pair Infinity Kappa 9.2i speakers.
Anyone here have some info on this amp?

I'm trying to understand how to use ARTA to analyze impulse responses.

I have successfully recorded Impulse responses from external source into ARTA. When I look at them, they look ok and and I can then click the "FR" button to show a smoothed frequency response from that IR. All seemed ok.

Then I exported the IR as a wav, and imported it into REW and looked at the resulting frequency response in REW and the two programs don't match.

Not being sure what I'm doing or if I'm doing it right. I found an IR, actually one I use for my headphones as a correction. I imported that file into ARTA by being on the IR screen and doing a File/Import/.wav and selecting the file. I did the same thing in REW.

When I look at the two IR's on the screen, they look the same. Or at least as much as I can tell. Both go positive, then negative at around 48u, then back positive at .103ms, etc. By using the cursor the timing looks the same.

However, when I click the FR button on ARTA to get a frequency response and SPL/Phase button on REW, the two response curves are nothing alike. Furthermore, since I know that the FR of my headphones is suppose to look like, I know that the FR from ARTA is way off. I have attached files for the IR and the FR from both packages.

What am I doing wrong? How do I get ARTA to properly show me the FR from an IR?





NOTE: The reason I'm doing this is I have an application where I need to record and IR from an external source (clapper). REW will not do that and since I own ARTA I'm trying to learn how to use ARTA to properly do that.

The Maeshowes with Pluvia 7.2 HD are playing. I had to taper down the bass by placing polyfill in the channels that are reachable from the outside. The other speakers are bass reflexes with Tangband W5-2143 and 3 notch filters (design Hobby Hifi, Germany). The Maeshowes project a fuller sound stage and play slightly louder. Apart from that the sound is similar. All in all I am pretty pleased with them.

this thread split from here:First build: Woden Sperrin

cogitech said:

...an extreme demo.

Click to expand...

Castle microTowers. I have a set with EL70eN downstairs. If anyone local wants to hear them we could drag them upstairs.

Link to original thread with link to plans: microTower bipolar ML-TL for CHR-70 or EL70. There ar emany more microTower threads.

dave

I bought a z5500 subwoofer, but I do not have its own decoder. A bypass is required for this, but I don't know how and which one to do because I don't want the sound quality to decrease due to bad hardware. Can I run it without a decoder? Or can you suggest another way?

I was a member years ago and built a bunch of Pass stuff with lots of help from forum members that I'm still listening to. Much older and not building much these days but still interested in what's going on. Builds take longer now as my hands start to shake if I go too long with the soldering iron. But still enjoy tinkering.

Hello friendly enthusiasts,

I have built a Purifi 1ET6525 based stereo power amp, and bought myself a pair of KEF R3 Metas.

Now I need a signal to feed it, that will be good enough to get the most from my system.

Does anyone here know the Hypex preamp/dac/streamer modules? How good is it actually? If price is anything to go by (1995 eur), it should be pretty excellent and fully up to the task, but I know that’s not always the case. What would I be paying for the same quality as a finished consumer product? Are there better alternatives?

Thank you!

What bias point are you using for modern production tubes? I know 1.56v is stated on the manual and is printed on the amp, but I have read somewhere that modern tubes requires a lower bias point as there not as sturdy as tubes made in the 60's

Hello! I´m from Brazil and learning about tube amplifiers and output transformers!

Hi Diy-ers,

I want to built my own PotCore inductors around 1 Henry.
Does anyone know how to calculate it - is there any calculator for Pot Core inductors?

Many thanks

This question is spurred by my likely purchase of JBL CBT 70J-1 for listening at the far end of a very long room. To be paired with a subwoofer in the corner to fill in the low end. And also someone's thread of some stunningly lovely line source speakers made out of umpteen small drivers with like aluminum face plate.

Anyway, a line source in theory is making a wave expanding in a planar fashion instead of part-spherically, thus the SPL falling off as 1/distance instead of 1/distance^2. Usually you can't have a line source subwoofer because to get the planar effect the line length has to be more than or approaching or something the bass wavelength which is super long. OK, too bad, so sad. But suppose in my 8' ceiling American room, I stack 8x12" in the corner. Now the airflow is kind of "constrained" by the floor and ceiling so has to expand in a planar sort of way. YAY! There's my plane wave subwoofer to match by plane wave mains.

But there's trouble in Paradise! It's too big...what if I use only 7x12"? 6? 5? 4? At the long wavelengths it doesn't seem you'd need the subs literally touching, or that you could reduce from 16x6" (hard to get to go low) to 8x6" etc. How much space can you leave between? What if you put the woofers on different faces of the tall enclosure? What if you wrapped the vertical array with a kind of snail to make a huge vertical bass horn feeding planar into the room?

Really the low frequencies in a room are more complex in time and the 1/distance concept not applicable like at the higher frequencies but at least as a "wave launch" kind of idea I wonder when is a bass line source no longer a line source...

I want to turn a pair of active BM6a into passive monitors, at least temporarily.

It's easy to just remove the back assembly with the amp, which leaves a connector that goes to both tweeter and woofer.

The BM6a (active) specs say the crossover point is at 2.2Khz, with the amp being 100W:
Dynaudio BM6A. User manual. English. Technical Specifications

Would I achieve good results using a cheap 2.2Khz crossover such as this one?

Or does it need anything special?

SHEVCHENKO Pure Tweeter Speaker Crossover 2.2KHz Treble Frequency Divider For 4 8 Ohm Home Audio Tweeter Unit 2pcs|Amplifier| - AliExpress

Here are the specs of the passive model:

Dynaudio Acoustics BM6 - 2-way passive monitor system

I recently picked up a few 2SK163L, which is the N channel compliment. Hoping to find a few 2SJ44 and try a some complimentary arrangements.

*edit - post title should read 2SJ44 L

Hello all, Robert here from the city of Enschede, in the Netherlands.
Currently building an Aleph JZM, former bulding experience with a boozhound phono and pre-pre, Muffsy phono pre, LM3886 amp, Akitika pre-amp, Elekit 8800 amp and DIY SUT with Lundahl 1931. All kits (LM3886 amp excepted), because I have no training in circuit design.

Hi, everyone! Hope you're all doing fine.

I'm implementing a motional feedback system for a subwoofer which is based on recovering the driver's Back-EMF and feeding it back to the amplifier, so the driver's Qts can be effectively lowered. That would, theoretically, alllow me to obtain a flatter response, extending further towards the infrasonics, with a smaller enclosure.
The problem is: to stiffen up the suspension through electrical means, whilst maintaining peak SPL, I'll need to supply more power to the driver. That wouldn't be a problem per se, if I weren't already planning to run the driver at its average (or "RMS") power limits.

The question is: from your personal experience, how far can we push the peak power delivered to a subwoofer (given that we respect both its excursion as well as its average power limits) before it suffers mechanical damage from excessive motor force?

About the Driver
The driver is an 18WP600 from JBL. Its specs are as follows:

• Fs: 35Hz;
• Vas: 294L;
• Qts: 0.46;
• Qes: 0.48;
• Qms: 20,4;
• AES Power: 1200W [300W average (or "RMS")].

(https://www.parts-express.com/pedocs/specs/264-474--jbl-selenium-18wp600-spec-sheet.pdf)

About the Power Amplifier
The amplifier will be a custom Class-D power amplifier. Its relevant features are:

• 8-Ohms output impedance;
• PSRR-enhanced, fully feedforward architecture;
• Average power capped by the PSU at 300W, peak power supplied by the bulk capacitors;
• Peak power still to be determined. Crest factor is expected to be anything between 6dB and 10dB.

About the Motional Feedback
The new desired speaker parameters are:

• 0.25 <= Qts <= 0.3.

The feedback will consist of (see picture attached):

• Sensing the voltage across the driver, V_Spk, as well as the current through it, I_Spk;
• Feeding a voltage representation of I_Spk through a gyrated model of the RL network represented by the speaker's Re and Le to a transimpedance amplifier, obtaining a representation of the voltage across it, V_ReLe;
• Subtracting V_ReLe from the scaled-down version of V_Spk, obtaining a representation of the back-emf, V_BEMF;
• V_BEMF is amplified and summed/subtracted to/from the signal fed to the power amplifier, according to increase/reduction in Q required.

After much trial and error, wasting materials, making mistakes, refinements, buying multiple versions of connectors, and many stupid mistakes... I've become somewhat of an expert at making high voltage umbilical connectors for separating a tube power supply from the amplifier. I wanted 10 conductors to cover many designs in the future. I also wanted to be able to send AC filament voltage across without inducting hum, so each cable has a twisted pair of 16 AWG that is shielded in a Belden-foil cable, this shield also has a 16 AWG drain wire which doubles to carry the safety ground from the PSU to the device, safety first. This leaves 7 more conductors. For the shorter cables (16 and 24 inch versions) I ran 20 AWG mil-spec silver teflon wires for these 7. For the longer cables (36 and 48 inches) these 7 conductors are 18 AWG silver teflon mil-spec wires. The designer can use these pins however they want. The designer can use a 36 or 48 inch cable to keep the "power brick" on the floor hidden. The shorter cable (16 inch) can be used when you want the PSU right next to or under the amp. The shield for the heater conductors (16 AWG) is dedicated as the safety ground transfer, and doubles to shield the AC heater from the other wires in the harness. Or you can run high-current DC filaments on these 16 AWG wires. The outer jacket of it all is made of 17mm OD 12mm ID latex laboratory tubing, very flexible, with high dielectric strength. The aircraft connectors themselves are rated to 500VAC / 700VDC but I would keep it under 500 because any wire also has to have a good rating. The connectors are 30mm diameter with 10 gold pins. I used a lot of high heat to solder the wire cups to make sure there were no cold joints, and heat-shrunk each solder cup inside the shell. Pulling the wire through the latex jackets, involves spraying some dry lube silicone on the wires, then using a fiberglass fish tape to pull the whole thing into the outer jacket. For the chassis connectors, you'd use the female connector on the PSU and the male on the amp, these attach with 4 screws in a 30mm hole, similar to how XLR connectors attach. I have some plastic hang-tags coming where I'll label the pins as to their wire gauge and if they are the shielded pair. I had to but a bunch of aircraft connectors to get the price break, so I'm on a roll making more of these than I'm likely to ever use. 10 conductors, but depending on the design an extra conductor can be had by finding the opportunity to share a ground, etc.

16 and 24 inch long cables pin configuration:

Pins 1 through 7 - 20 AWG silver/teflon mil spec (purpose as needed)
Pins 8 and 9 - 16 AWG Belfoil shielded twisted pair (typically for heater circuit) (high quality Belden cable used here)
Pin 10 - Shield drain wire (you must use this pin to carry the safety ground across so that both your chassis have a safety ground)

36 and 48 inch long cables pin configuration (thicker gauge is used here):

Pins 1 through 7 - 18 AWG silver/teflon mil spec (purpose as needed)
Pins 8 and 9 - 16 AWG Belfoil shielded twisted pair (typically for heater circuit) (high quality Belden cable used here)
Pin 10 - Shield drain wire (you must use this pin to carry the safety ground across so that both your chassis have a safety ground)

Voltage rating (using PTFE insulated wire)

Pins 1 through 7 - PTFE wire is rated 600VAC 840VDC, the connector itself is rated 500VAC 700VDC, therefore the whole cable is rated 700VDC if built as shown.
Pins 8 and 9 - The Belden cable used here is rated 300VAC 420VDC but is meant to be used for the low voltage heater.
Pin 10 - This is the safety ground, it should not be carrying any load

I'm 49 years old.
I don't (never used to) generally feel the cold, and I'm trying to save a bit of cash by turning the thermostat down in the house by a few degrees.
I'm generally ok, and despite it being 0 - 5 degrees (celcius) outside, it's not bad indoors.
I'm wearing joggers and a tee shirt. The stat is set at 18 degrees but I feel a little chill on my arms.
Am I ready to don a cardi?
I've never worn one before and I don't feel wearing a coat in the house is right..
Should I bite the bullet?
Any other cardi wearers here who can offer advice?

Great to meet you all.

I'm a head-fi obsessed enthusiast considering my first DIY project to build a headphone amplifier to power my favorite headphones these days - Modhouse Tungstens. These particular headphones are notoriously hard to drive being an oddity - low sensitivity, high impedance planars. Therefore, I first stumbled on this site attracted by the Elekit TU-8400 DIY kit capable of running KT170s, which has started to become a popular tube for driving this particular headphone.

I don't have much recent experience soldering so that's a concern but looks like Elekit's amplifiers are relatively newbie friendly.

Happy holidays everyone!

I'm in the process of making an AD1862 dac board and would like some input on how to separate analog and digital grounds.

I want to make a single ground plane as Guido Tent recommends, and use proper positioning of the the components to avoid the digital cicuitry creating noise on the analog ground. This is very easy with the AD1865 and the PCM63 chips, as the digital and analog parts inside the chips are neatly separated along the middle. But with the AD1862 it's not so easy. Looking at the datasheet it seems like the lower left part of the chip is used for digital, and the rest is analog. So how do I position two chips next to each other without mixing the grounds?

The only way I've managed to solve this problem is to make separate mono dac boards. I've created the circuit on a prototype board. It works fine with a mono board. Very low noise. But with two dacs side by side on one board, the left channel gets really noisy.

Any input on this subject is very welcome.

I bought an arbitrary function generator, it will do a sine wave. I need this to set my adcom 5800 bias correctly. Can someone tell me exactly how to do this on this machine, according to adcom specs, I have it set on 1khz but I don’t understand the (Ampl) on the bottom what to set it at. Also when they say input, what is that referring to?

Philips AD1255/M7full-range & AD5201s Bombardon enclosure help

Hello,

I'm wondering if any kind people can help me with making a decision on how best to utilise and to make a cabinet for these drivers. I'm fortunate in that I have 2 x near perfect AD1255/M7 full-range drivers and a total of 4 x (2 Perfect & 2 with marked cones) AD5201s/77 Bombardon Woofers.

I was planning on making each cabinet with 1x AD1255/M7 and 1x AD5201s/77. The plan was to use the Bombardon with the recommended crossover point of 800Hz and use the AD1255/M7 for the rest of the frequency range up to around 15KHz and then supplement the +15KHz with a Super-tweeter.

I have a DATs V3 and have measured all the driver parameters, I've also created WinISD driver files for all the drivers if anyone want to have a look at the driver parameters. Since the forum wouldn't allow me to upload the WDR file extension directly i've just added ".TXT" to the end of the file extension. The parameters can be viewed with Notepad as they are or if you want to add them to WinISD just delete the ".txt" part of the file extension to change it back to the WDR file type.


I'm also thinking that the largest enclosure I can get away with in the space I intend to use them would be in the 300 litre volume range.

Any help would be much appreciated.

Dear all, my 2011 Bassman TV 10 is a great sounding little bad amp; unusual nowadays for having a 12AX7 valve preamp. Sadly it went quite a couple of months ago and I sent to the UK Fender Service Centre in Liverpool. They said that the PSU had failed and no parts are available anymore. The amp is effectively scrap. He did say that it was possible to replace/repair the PSU on the IC but they do not do that. Can anyone here help? Thank you for your time in reading this thread and I hope that everyone had a good Christmas.

I'm not sure was it Santa or Satan who brought me this for Xmass??


It was sitting in humid and cold shed for years, but apart of few unimportant knobs and covers, it is complete. I left it in worm and dry to condition for some weeks before attempting to power up.

Half a century ago this was the top that money (a lot of it) could buy, but question is is this worth rebuilding today when REW and soundcards do all the job?

Experts,

I have a rotel rmb1575 which has 2 IcePower 500ASP and 3 500A modules. The amp is showing red protection on power up. I have the auto trigger off. I was troubleshooting and here are my notes. Initially I noticed that the surround speaker outputs were showing continuity. Others were not. Then I wiggled the inductor that was touching the terminals which seem to have insulated wires wound on a ferrite and then the short went away. This may indicate that there was a short which went away. I switched it on hoping that would be a fix but its not. How do I isolate if the issue is with modules or the rotel protection circuit or output boards. I also noticed that one of the 500ASP module showing a greed led on the board lit. The other board does not. Any troubleshooting steps to check and isololate. Thanks

Does anyone know if there is available a simple "soft switch" which I can put between the transformer of my preamp and the mains? I think it would be a good idea to have something like that. Opinions? Thanks.

Hi,

I’ve a limited experience in building my own speakers, and by now the best speakers I’ve built are by far the Silbury with MA10.3.

What is the DIY speaker that you have built, designed or heard that is the best for you?

Please explain also why you consider it “best”.

I consider Silbury with MA10.3 superior to FHXL with MA11MS because of the detail and extension they have, but still the FHXL is a very very good speaker and extremely easy to build.

Thanks in advance to everyone.
Roberto

Hi all,

Well ... I have been working for some time now on a 6 layer DAC PCB that I am just about to send off for manufacturing (JLCPCB) - and then I notice that the only surface finish JLCPCB has available for 6 layer PCBs is an ENIG finish, which means a layering of nickel subsequently covered with gold.

And remembering that e.g. WBT (the German connector company) and others over time have been critical of nickel as a sublayer in e.g. connectors I was wondering if there is a current view on nickel's sound imprint?

Cheers & thanks for any insights on this 😉

Jesper

Hello,

Whenever I search for something about speakers I get this forum suggested.
So I registered today and am bringing you a few measurements.
I will soon be 50 but I have been building loudspeakers since I was 16. In the meantime I have made two PA systems and a dozen home hi-fi speakers.
I'm from Germany and have my own small woodworking section with a table saw and and.... I always build something different for myself privately, but mostly speakers ;-)
I don't claim to know much but I don't let up until I like it.
So sometimes mistakes creep in, small problem, I am honest and learn from it.
This forum seems to be very active when it comes to DIY.
I like that !!!

I try to deliver measurements, photos and my modest experiences from time to time.
In return I take advantage of your experiences 🙂

Best regards
Andreas

New here....having channel/power supply issues with amp and/or graphic EQ. Hoping to gain some knowledge and suggestions to correct the issues. I regularly loose left channel....if I partially unplug the EQ (Pioneer SQ-550) to a half-way loose-ish insertion I can regain stereo. First guess is bad power cord, but I'm no expert. Looking for other thoughts, recommendations and/or actions to take to correct the issue.

Make offer in thread if interested.
I don't know anything about it.

MFD. by Audio Development Transformer TF1A02LA A8691 365V -- NH USA --

What should I have in mind when replacing a bipolar capacitor for the tweeter in these speakers? Should I just get the closest value I can?

If that is the case I can get ahold of some Jantzen Audio Cross Caps at 8.2 uf if they will work

For sail. genuine components guaranteed, matched pairs are matched by a curve tracer. A lot of DIYers bought those componets from me years before.
2SK163 2SJ44 have better complementary characteristics than 2SK170 2SJ44.

NOS JFET FET
Genuine Toshiba matched 2SK170GR 2SJ74GR pair(one pcs 2SK170GR and one pcs 2SJ74GR), 10$ per pair.
Genuine Toshiba matched 2SK170BL(two pcs 2SK170BL) pair, 8$ per pair.
Genuine Toshiba matched 2SJ74V(two pcs 2SJ74V) pair, 10$ per pair.
Genuine Toshiba matched 2SK369V(two pcs 2SK369V) pair, 10$ per pair.
Genuine NEC matched 2SK163L 2SJ44L(one pcs 2SK163L and one pcs 2SJ44L) pair, 8$ per pair.
Genuine NEC matched 2SK163M 2SJ44M(one pcs 2SK163M and one pcs 2SJ44M) pair, 8$ per pair.
Genuine Renesas unmatched 2SK213 2SJ76(one pcs 2SK213 and one pcs 2SJ76) pair, 15$ per pair.
Genuine Hitachi unmatched 2SK214 2SJ77(one pcs 2SK214 and one pcs 2SJ77) pair, 15$ per pair.

PCBs, all SMD componets are populated(except OCXOs and through-hole components and connectors),
PCIe USB Card : PCIe 1x, one USB 2.0 output, embedded sc-cut ocxo, external 10MHz input, external DC input, LT3045 regulator, ASM3142 chip. 300$ per pcs
PCIe Network Card : PCIe 1x, one gigabit SFP output, embedded sc-cut ocxo, external DC input, LT3045 regulator, WGI210 chip, 300$ per pcs
10MHz clock board: one sine wave output, 4 square wave output, LT3045 regulator, 300$ per pcs
Gigabit Network switch: two SFP ports, four RJ45 ports. embedded sc-cut ocxo, external 10MHz input, LT3045 regulator, 300$ per pcs
USB isolator: ground isolated, full USB 2.0 480MHz, one USB input , one USB output, embedded sc-cut ocxo, external 10MHz input, LT3045 regulator, 300$ per pcs
USB DDC: one USB 2.0 input, [OUTPUT, Spdif(DSD128 PCM384 max), AES(DSD128 PCM384 max), IIS(DSD1024, PCM1536 max), WORD CLOCK] embedded sc-cut ocxo, external 10MHz input, LT3045 regulator, 300$ per pcs

It will take 7 to 10 work days to arrange test and shipment. Shipped by registered airmail with tracking number or DHL or Fedex or EMS or equivalent.

Import duties, taxes, Paypal fee and charges are not included in the item price or shipping cost.

Hello gents,

I'm thinking of renewing the components of the SP2225 corss-over of my kef reference model 3's. I do have the schematic with the values. Replacing it with oem components is impossible so I need to source it somewhere. The speakers are working fine at the moment so the question arises...why would you replace it?...I wandering what kind of put-holes or pit-falls I might fall into and what to look for besides the obvious. I will measure the orginal ones first and compare them with the scheme below. any advise more then welcome....

happy new year...

Hello all,

After doing research on the web for a high power chip amp with built-in DSP and Bluetooth, we’ve realised that most products on the market had at least one major drawback.

Zoudio has a great product but the power is limited to 4x50W. The Beocreate 4 channel amplifier has limited power as well. The Wondom JAB5 has in theory all the features that you'd need but the sound quality is relatively poor.

We’ve therefore started to work on a new chip amp board that’s designed for the DIY market and we’d like to have your feedback. The board will have the following features:

- 4x200W @4Ω and 10% THD+N
- Typical THD+N of 0.01% (@ 1kHz, 70W, and 4 Ω)
- 4.0, 2.1, 2.0, and 0.1 configuration
- Built-in DSP using the ADAU1466
- Bluetooth 5.2 with aptX and the possibility to create stereo pairs (and more)
- AUX and I2S input
- ES9028Q2M SABRE Reference DAC
- LEDs, Buttons
- Possibility to connect a Raspberry Pi (for example to use as a streamer) or an Arduino

We’re considering making the board modular so that some of the components can be swapped for others, also considering the current chip shortage situation.

Pricing is still being worked on but we want to keep it as affordable as possible.

Hi everyone,

I have a SOUNDSTREAM LW4.500 amplifier that powers on, is not in protection mode, and all voltages are present as they should be.

However, it doesn’t produce any sound output, and without a schematic, I can’t figure out the path the input signal takes.

Can anyone help me?

Thanks!

Giovanni

Hello, I designed a new pcb for a quality amplifier circuit, I tested it, the sound is good, the bass is strong.

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Selling a pair of the very good SEAS MCA12RC H1304 bass-midrange driver, completely unused, originally wrapped
145 Euro plus shipping

Can a Hickok 539 test a GU-50 tube?

I am an heretic and I am going to hell because I want to built a class A amp that is not a Pass project!
Having admitted to that, does anyone know anything about the Hiraga 20W class A amp? The somewhat incomplete schematic is posted in several sites so someone must have seen it and have some comments about it. It could be an interesting little project that distances itself from the usual crowd and that, most of all, does not involve buying mosfets, which I don't have.

Works well. Comes with DIRAC already pre-loaded.

The screen works fine. Seems like the phone catches the display scanning. I can take more pictures if desired.

US$500 + shipping CONUS

I have a question, that must have a simple answer, but has been driving me crazy. I am simulating a basic 3-stage BJT amplifier, the circuit you will recognize from Bob Cordell's book on Designing audio Power Amplifiers. I have attached the schematic. When I simulate as a simple block diagram, everything works as I would expect. When I simulate the circuit, there is a dependence of the VAS current and emitter degeneration resistor (R5) that manifests itself as an offset in Vout. Seems like that offset should be driven to zero my the nature of the closed loop, but it does not seem to be the case? Any thoughts would be very appreciated.

I would like to give you some impressions about star grounding.I hope the topic will help you avoid grounding issue.
1,star grounding is not problem with mono system,as a result it can avoid inner ground loops.surely it is not problem with dual mono stereo amp.
Ok then how about when the equipments are interconnected?
Notice,there are two way to make interconnector cables,connect the cable shield on both ends or connect the cable shield only at one end.whatever there are still no loops between the source and power amp.

Zang

As the title suggests, I have a couple of questions about measuring ribbon tweeters. My goal is to not blow up my measuring amp, destroy one of these tweeters, or get bad data.

Here is the ribbon in question: GRS RT1.R. These are back ordered and I have only two so I really do not want to break one.
https://www.parts-express.com/pedocs/specs/272-202-grs-rt1.R-8-spec-sheet.pdf

I have this capacitor I plan to use to measure it. 47uf
https://www.parts-express.com/Dayto...0V-Polypropylene-Capacitor-027-448?quantity=1

1. Will putting a single cap in series with the ribbon when I measure it throw it out 90 degrees out of phase? If so, how do I make up for that in VituixCAD?
2. I am assuming the 47 uf cap will cross so far below the range I plan to use it (4-5K and up) that it won't affect the measured frequency response where I plan to use it. Is this correct?
3. I can just use my regular impedance jig to measure this right? It is one of those diy 100 ohm jobs. I got it from A4eAudio (thanks again bud)

I plan to assemble this thing tomorrow and take measurements sometime this weekend. I will be posting a build thread with pictures once I get it assembled.

I've been given some components that I want to use to build my home theatre sub.

• Vifa M25W0-49
• Whatmough 150W plate amp.
• Sliding port
• Sheet of 18mm thick ply, 900mm x 2050mm

I have various tools such as a jig saw, circular saw, drills etc and enough handyman skills to build things.

I want to build a sub box to place under my entertainment unit (400mm clearance). Possibly down-firing as I have kids with curious fingers.

I don't know where to start!

Almost two years ago I started a thread to investigate the opportunity for a diyer to build a real low jitter oscillator.

Nowadays a couple of GB have already gone, but since it seems there is still enough interest, to keep the discussion tecnical only on the main thread, I decided to start a separate thread for the group buy.

You can find every technical detail and related discussion on the master thread at The Well Tempered Master Clock - Building a low phase noise/jitter crystal oscillator - diyAudio

Available parts, prices and Order Form in post #883
The Well Tempered Master Clock - Group buy

Quick guide for GB in post #805
The Well Tempered Master Clock - Group buy

Order summary
TWTMC_Summary of Orders - Google Sheets

Hello. Required post to activate my new account. Will post separately to discuss other topics. Many years of playing with various audio and video equipment. Looking to expand my knowledge.

Hi everyone,

I’ve been working on designing a custom speaker and could really use your thoughts and suggestions to improve it. I found a pair of Lii Song Silver 10 drivers at a low cost and decided to design a pair of speakers around those drivers. My goal is to build something unique with the following features:

1. A full-range driver mounted on an open baffle.
2. The ability to adjust the angle of the full-range driver to create an omnidirectional sound effect.
3. A sealed subwoofer to handle the low frequencies. I’ll be using 10 inch Dayton reference drivers for this.
4. A tweeter facing the front wall to enhance the soundstage.

For inspiration, I’ve looked at Decware’s ZROB (for the 40-degree angled open baffle) and Perry Marshall’s live edge dipole (for the rear-facing tweeter concept).

Here’s a rough idea of what the design looks like so far.

I’d love to hear your feedback—whether it’s design tweaks, suggestions for drivers, or even pointing out potential issues I might not have thought of.

Thanks in advance for your help!