Hi,

I've just bought some of these Soviet Valves, attracted by the fairly high gain, or similarity in some aspects, to KT61.

Has anyone here experimented with them?

Any advice/designs/recommendations, that you could share?

TIA,

Greg

Is it wise to use a dummy load when testing a preamp? If so, what resistance would be correct?

Help which 10" woofer I chose out of these 3 SB or Alcone Or Visaton ???

Hello

I would like to ask any opinion from those people who used or heard these SB woofer in 3 way system or as a sub-woofer.
I want to use it in a 3 way system in a 75L BR enclosure.
AudioNL store
Another option I think about the Alcone AC 10 HE
Alcone AC 10 HE
These is the Visaton
Visaton - Lautsprecher und Zubehör, Loudspeakers and Accessories
Visaton produce some of my favorite drivers all do I never heard these driver
Any pro and contra welcome before I buy.
Thank you very much🙂

Greetings Gabor

Hi All,

I am Mani from India. Happy owner of Yamaha NS 1000 Which is currently driven by Yamaha AX 900.

Recently I had issues with Yamaha Tweeters and Woofer due to the aging (yeah its 40+ years old) and magnet juice are reaching the End of Life.

Once I have replaced the Yamaha BE Tweeter on left ( purchased online) and Midrange too. Since the replacement drivers are old too I no longer have thought of replace them with originals.

As all know the Yamaha NS 1000 Cabinet solid build ,planning to replace the Woofer,tweeter and Midrange once they stop working, frankly speaking we cant ask more with 40+ years drivers anymore. My dream is to replace some quality drivers to justify the cabinet without much work.

1.Morel CAT 308 replaced the BE Tweeters, the sound quality has dipped still very decent sound I get from these tweeters.

2.One of the Woofers Magnet ,Hence I have ordered Dayton DC 300-8 12'' Woofer which should fit within the cabinet without any alteration.I am Yet to receive the woofer to install and see if the money is well spend on the woofer to match atleast to certain level of Original woofers.

3.The Midrange are fine working and I am looking for a decent replacement without breaking bank.

I listen average and above average volume and more in India Music and Progressive Rock.

DIY Forum has helped me to escape from nightmare when I think about aging Speaker 🙁. Successfully i have rewired the drivers for one Speaker with 16 Awg for Woofer and 18 AWG for Midrange and Tweeter.

Any suggestions for the Midrange are welcome also let me know any good replacement woofer in case Dayton DC 300-8 is not impressive.
😉

Good day, tubers!

I've done a lot of reading on this forum, very informative. This is the first time I've posted to any forum, ever.. so if I am posting in the wrong section, or doing something otherwise incorrect, let me now.. I'll rectify the issue.

To the matter at hand.

I will be constructing an amplifier based on the infamous Mikael KT88 SE schematic that seems to be a favourite schematic to build. I want to used KT150 tubes. My knowledge of electronics theory is limited (relating to valve tech) but I'm confident with a soldering iron, as well as following basic safety guidelines.

I've collected most of the primary hardware (PTrans, Tubes, Tube Sockets, Motor Run Caps, Chassis) but I will need some guidance from you lot, who's collective experience is a huge asset. I'm not sure where to start with my questions, so I'll just start..

• Will the 6N1P have enough output voltage to drive the KT150's to a reasonable level?
• If the 6N1P doesn't have the drive.. can I incorporate a 6SN7 preamp stage into this design? (I'd love to do this regardless)
• Would 3k Hammond SE OPT's be appropriate for this design?
• Are there any obvious changes that I would need to make to this design in order to use KT150's? (I've thought about making a selector switch to allow the use of KT150/KT88/6L6)

I realize that this beast will require a PT with substance, so I purchased a Hammond 378CX. I'll be going with SS rectification. I'm guestimating around 300ma draw, maybe more.



Let's get the ball rolling.

Cleaning out.

The following are only $2 each:
Dayton Audio xovers
2K-LPF-8
2K-HPF-8
2K-LPF-4
3K-LPF-8
3K-HPF-4
4.5K-LPF-4
4.5K-LPF-8


Of course... at this low a price you can remove and use the coils and caps as you please...


Air coils (also $2 each):

0.36 mH 0.37ohms
0.416mH 0.28ohms (on blue board with 10W resistors)
2.1mH 0.78ohms
0.64 mH this is the one on the 2K-HPF-4 board shown missing capacitor

For $10:

1.00mH 0.30ohms Janzen Audio 15 gauge, PE price $17.48 part# 255-422

Price plus shipping from 47150. Prefer cash, but will accept Paypal if you pay the fee. Minimum order total $10 plus shipping. Will be posting many other things in the next week or so, mostly just little odds and ends including free stuff.

Hi

I got to thinking about the acoustic effects of a mesh in front of the drivers.

If the mesh is 1mm metal and the holes are 4-5mm the effects are probably minimal ( as this is standard for many PA-solutions).

But what if the mesh was much thicker? - say 20mm? and the holes were Ø30mm? I'm guessing the holes will have an resonance somewhere in the audible spectrum. Below resonance the holes will make little difference, - as long as airflow is kept below turbulence. What happens above resonance?

I'm wondering if the holes could be tuned to give a boost over a (small) range?

Most of all I'm curious 🙂. Hornresp can do a lot, but I cannot figure out how to put this one into HR.

Kind regards TroelsM

I have a complete pair of Madisound MDY-4 two-way speakers with aperiodic vent. They are fitted with a pair of Dynaudio 17W75 EXT woofers and Dynaudio D28/2 along with one each variovent in each cabinet. I posted about these speakers for a gentlemen in the Netherlands looking for information on the kit. Photos and crossover diagrams are there.

I no longer need the speakers and clearly the value is in the drivers and not the complete speaker. If you have an interest in the drivers I'd be happy to remove them and sell them to you. I just want to know if there's interest before I start dissembling the speakers.

One note: the tweeters have some slight creases in the soft dome. I haven't tried to repair them as it seems inaudible. There are steps you can take to try and de-crease them, or new diaphragms are available out of Australia for about $25 each.

Let me know if there's any interest out there.

Hi guys,
Please share your technique in drilling holes to a 10mm aluminum faceplate like the chassis shown (diyaudiostore)
Deluxe 4U Aluminum – diyAudio Store


I need to drill 19mm for a front panel anti-vandal switch

Thank you!
Abe

Using vinyl input to get softer software???

Master boot vinyl record: It just gives DOS on my IBM PC a warmer, more authentic tone • The Register

Who would have guessed.

Hi,

I'm designing an amp based on the LM3886 (I have a separate thread covering this over in Chip Amps), and with it a power supply for delivering +/- 28v-or-so.

I'm new to LTSpice, but thought the PSU circuit would be a good candidate for a first circuit to sim, so I've modelled it as per my schematic using 2 AC voltage sources running at 50Hz, around 29.5v to emulate the max output from a split secondary 18v toroidal transformer (UK mains).

The load circuit is borrowed from post 12 in this thread, as LTSpice doesn't have a LM3886 model included as standard, so this may skew things a bit!

It's full bridge rectified per rail, using 2x10,000uF caps for smoothing. According to the LTSpice sim, this gives about 600mV of ripple at just over 28V.

My question regards the current at C1/C7. The sim shows just under 80A immediately, quickly settling to around 11A spikes per half wave. Is this correct and normal, or will it quickly degrade the smoothing caps (at least C1 and C7)? The spikes last around 1.5ms. I do have an NTC thermistor pre-transformer for inrush limitation.

I notice that by removing the PI filter resistors, this current reduces to 8A, but the ripple waveform is much sharper. Will this matter?

The caps I've chosen are Nichicon UKW 35V, which have a ripple current rating of 3.7A. Mouser doesn't have anything resembling the UPW type I'd like to use (long life, low impedance, high temp) at 10,000uF 35v in the leaded type. What are your preferred caps for this kind of application? I can redesign my board a bit to cope with larger caps if necessary (currently it can fit 2x25mm diameter caps with the resistors in between).

Thanks, Christian

Hi,

I want to change the OPs in my vintage Kenwood PreAmp .
Some Modifikations were discussed here years ago.

The goal is to place good sounding OPs with less DC-Offset at the outputs.
I guess i have to choose low input bias current types.

In the schematic Output there is a JRC 5532DD which causes 150mV Offset.

Is there OPA2132 / OPA 2134 a good choice ?
Or maybe a LM4562? The input current is higher, but about 20mV Offset would be acceptable.

The input buffers are JRC4580DD with 100mV Offset and a very low slew rate.
Maybe there are the LM4562 a good choice too ?

Jay

Dear fellow audio enthusiasts:

I have an old pair of Acoustat 2+2 speakers that my beloved cat cannot resist using as scratching posts. The original black fabric coverings are shredded in various places, and consequently the speakers look beat-up. Rather than replacing the original fabric with some other cloth covering, I thought it might be better to use perforated metal sheeting or some other material. Like the Martin Logan speakers.

Some questions:

1) Have other Acoustat owners with cats had the same problem? Any good ideas? Not willing to get rid of the cat, remove the cat's claws, or banish the cat from my listening room. Maybe there is a chemical that would repel the cat, but not slowly poison it?

2) If I try perforated metal sheeting, will it degrade the sound?

Any helpful ideas will be welcome. Please, no jokes about murdering cats or the like.

Happy listening, and stay healthy,
Joel Dickman

I made a change in the audio system, and installed a mid-range speaker, but I have a question about the frequency setting, any suggestions to do it

Looking for the following transformers if anyone has them. They are for an Auditronics 110 console...

(4) Jensen JE 6110K-A (PC Mount) (or JT-110K-HPC)
(3) Jensen JE-123-S (PC Mount) (or JT-123-SLPC)
(1) Cinemag CM-3301

Also looking for:
(2) Auditronics Foldback 2 Master Modules
Auditronics 110A or 110B Modules
Auditronics IM or SIM Line Input Modules OR Harris IM and SIM Line Input Modules
Auditronics SSM4 Stereo Assign Modules OR Harris M90 SSM4A Stereo Assign Modules
Auditronics F2R OR Harris M90-A2 Stereo Faders OR Penny+Giles PGF1122/C stereo faders (spec no. D26647)

Anybody from Pune here ?

My KA-5002 is not working. I may have narrowed it down to the amp board when I experienced no issues using an amp board from a working donor. There is a short somewhere I cannot narrow it down further. Test points are good until the protection circuit and B-.

Drivers are new KSA1220AY/KSC2690AY pair. Diff inputs are also new, and I can center those with Vr1,2 fine according to service manual.

B- drops to -24v on a 40w dim bulb. If I pull the output transistors it gets proper -35v on dim bulb, bulb is dark, relay clicks. With outputs in, the bulb is really dim, then brightens up a little after 2 seconds, no relay engagement.

I checked resistance of the output emitter resistors they all are good. I did diode test on the output transistors twice, check out good. Unit works with donor board, relay clicks in fine.

I did find and replace a bad De6 flyback diode.

When powering on with dim bulb, Qe18 collector briefly surges to 30V, then drops to 3v. Qe17 emitter reads 3v on dim bulb.

I need help from the pros! I would appreciate your investigative skills. I put red dots on test points that read bad. Pins 6 and 14 go to relay, it got cut off.
Kind regards.

I hope this is the right place to post this, I am a complete novice, but have managed to build the RJM Emerald Phono stage with switch board, Toms' Modulus-86 along with his latest pre-amplifier with univeral buffer and a pair of Frugel Horns with the Alpair 7MS.


Everything works, but I have to turn the volume control nearly all the way up to get a reasonable volume from my speakers, but would still prefer it to be louder, but not ear splitting volumes. Hopefully someone here would be able to advise what I need to do to improve things.


If it helps the pre-amp is built with 26db gain and the phono cartridge sensitivity (Nagaoka MP-200) is 4mV.

Thanks

I got my hands on a Klipsch SW12- it had a loud power supply hum and intermittent signal. I figured it was a bad ground connection or some caps went bad, so I traced the wiring and checked for continuity. Ground came up good, so I moved on to the 30 year-old electrolytic capacitors. I put my Mouser order in and waited a week for parts to show up.

Parts came in today around 1, and I spent the next four hours checking and marking polarity, desoldering old caps, and installing 22 new capacitors.

I plugged the unit in to the wall and hit the on switch. No smoke, which was nice, and no hum, which was nicer. Before, it would hum with nothing connected. Test 1 complete.

I unplugged it from the test outlet and hauled it upstairs to the home theater. After fishing out some RCAs, I plugged everything in and turned the system on. Got faint signal through the sub with the knobs all the way up, and a new, lower hum, but only when the sub was connected to the AVR's sub-out. No hum otherwise.

I'm not sure where to go from here... something is rotten between the input jacks and the amplification stage, but I'm not sure what it could be. The hum is volume dependent, so amplification seems to be working but signal isn't reaching. I'm back to thinking it's a grounding issue because the hum is only there when the input is connected.

What are my next steps for troubleshooting? Am I missing anything obvious?

Dear Members,

would you please validate this below design of mine ?
Usage scenario:
- background music on low-medium levels (no primary hi-fi)
- multiroom use: room1 big living room, room2 bedroom
- newly renovated flat, electrician put all cables into the walls already. Unmovable, sadly. Luckily they're standard stranded copper cables with good conductor thickness
- bedroom: 2 upper corners pre-cabled
- living room: 4 upper corners pre-cabled

So, I'm in the adventure of creating a multi-room solution which will involve some kind of miniDSP and 1, max 2 additional "nonintrusive" subwoofers as well, nicely placed here and there.. measuring will decide (UMIK-1 provided).



My part is to choose drivers, do sizing, port tuning, all this kind of stuff you know. And the crossover. Here I'd like to hear your opinion about what I've chosen to do in the upcoming days.



Tweeters:
I chose the HiVi RT2C-A AMTs, I might rotate them 90° to convert it's wider horizontal dispersion to vertical which might come handy when ceiling-corner mounted. Although from there, pretty much everything in every angle hits a wall/ceiling (which is good in this case at least).
Nominal 8 Ohms, 94dB average, stable impedance (easy on crossover side), planned to be crossed with 3rd order at 2500Hz.



Midwoofers:
Aurum Cantus AC-165. Peak at around 8k - I don't think I should take much care of it with a 18dB/oct slope at 2500Hz, otherwise good feedback so far.



Crossover: I called this site for help .. and made my calculations.
Reading a lot on the internet I think room modes modify a speaker's amplitude response anyway, especially when we talk about bacground music ceiling-cornered speakers with multiple possible listening positions.. so flat amplitude response isn't what I'm striving for, but rather phase and group delay coherency. -> Bessel.

I opted for a 3rd order Bessel, a good compromise to be not yet that complex like an LR4 but still a little bit more steep than a 2nd order classic good-old BW. And then we'll see. (In amplitude response it has -5dB at XO point for each driver so summed up the two, at XO point the system has a +1dB lift which is negligible in my case).

I've never ever heard a Bessel but can change anytime to any other config, for now that's it.



Playing together:
Tweeter is at 94dB average, I calculated 3 types of differently damping L-Pads on this site, for 7.5 Ohms. That will be pretty much exact (seeing the somewhat blurry impedance line of the driver). We'll se which I use - if at all. If corners will lift midbass response to some extent, a slight "V" in the overall SPL curve won't harm anybody, of course this breaks xo symmetry but end result is more important than textbook crossover..

Midbass drivers are at 91dB, a Zobel (series RC in parallel with driver) would take care of flat-ish impedance curve and grant a well funcioning crossover at the XO point, where midbass is at 12Ohms already - and rising. Not sure if I want to overcomplicate this passive xo network with an additional RLC for flattening the impedance peak at the lower region of the woofer. In case of a low damping factor tube amp I'd do so but drive here would be most possibly a TPA3116D2 Class-D with low noise regulated, well damped power supply so I don't think an RLC is needed.




What do you think ? About the whole, limits taken into consideration.
Any detailed advice is welcome, or if you say "great, go ahead, nice plan" - that's welcome as well.

At the end when all drivers are up on the ceiling in the corners, multichannel amplifier built and ready to serve, active subs placed, everything connected.. a small miniDSP solution will handle room modes (especially in the bass region) at the possibly most favourite listening position (big sofa in front of the tv). Another miniDSP doing the same in the bedroom (or even not..).

Mentioning this just for the sake of completeness.
(Multiroom: volumio or roon or picoreplayer, 1 or 2 RPi-s with decent dac hats).

Hey, I just purchased a quite old Digidesign interface, and although it sounds quite alright I think it could use some help with a new clock design and some electrolytics and maybe opamps replacement.
I am thinking of two crystek clocks powered by a quality regulator.
I made some digging and I can't decide where in the existing clock should I intervene. Should I search for a Oscillator Frequency selector pin and send one clock signal where I should be or remove the old crystals and buffer inverters and go to their output for both the crysteks. Here an image of the existing clock:

Editors Note:
Deep in the thread for the Open Source Monkey Box:
Open Source Monkey Box

were some posts regarding mounting the speaker flush in the wall. This is often desired for studio monitors and people who just happen to have an adjacent closet where speakers could be mounted. Since in most cases a in-wall flush mount speaker is going to have to be a good old (monkey) box type, the excellent and efficient Monkey Boxes are a logical choice. Of course the port would have to be moved to the front or converted to infinite baffle, and the crossover redesigned, so I’ve corralled the relevant posts here on a new thread hoping that it will take off with some good design work!

Variac,
DiyAudio Editor
—————————————————————————————

In post 835 Open Source Monkey Box

You mentioned a "user option" to decide whether to keep the port on the back, as is specified in the documentation, or move it to the front as either a slot or round port.

For flush mounting, it would be preferable to move the port to the front.

I know you originally built a box with a front slot port. But you also mentioned that the back round port seemed to improve low freq response a bit. Would a front round port do the same?

Either style of front port seems to require enlarging the box height a bit. Any thoughts on the best way to accommodate a front port? Slot, round, position, how much to expand box?

thanks, gabo

By the way FYI, I'm back to using the passive crossover. Mostly due to protection issues. Some very expensive tweeters in there that I don't want to destroy due to a power blip or other issue that might cause an amp to throw out a spike. Protecting the tweeters with either a cap or bulb introduces undesired effects compared to just using the full XO.

Good morning to all, I comment, I have on the table a class D mmats amplifier model 1100.1, 2 irfb4710 and hip4080 controller were replaced, I put current and remote and turned on green light, I assembled the amplifier and when I tried to do a test it turned on red light (default) and it is only connected + - in the amplifier, that is, without the remote control cable, does anyone know how to remove it from protection mode? I already tried with my tester most of the pieces and they are in good condition. Thanks in advance.

What's everybody using with their F series amps?

Any good DIY options out there that are on the easy side to build?

For some years I have been using self-built star-quad cables, I am satisfied and would like to know if anyone has tried similar cables.

The very low 30 pF / m capacitance makes the cable suitable even for amplifiers with low output currents. In the 662g cables the four conductors are connected to the + and - phases of the signal diagonally. They are kept approximately 25mm apart with plastic cross brackets. The capacitance between two conductors decreases with distance, even with some points where the cables approach the average capacitance remains at around 30 pF / m.

An aspect not considered of the speaker cables is that compared to the system they behave like the primary winding of a transformer. At 10 KHz the electromagnetic waves have a wavelength of about 10 Km and at the audio frequencies the whole audio system is subjected to the homogeneous flow of the magnetic field generated by the speaker cables. The star-quad configuration reduces the magnetic field generated by the current sent to the speakers and minimizes the chained flux with the amplifier circuits and signal cables. The possibility of unwanted feedback is reduced.

The cable is very cheap on page 662g you can find other photos to make a replica.

Hi,

in a (maybe stupid) moment I bought a China made DTS AC3 module from Ebay. Documented is only a simple pinout (see pict).





Has anybody more information about the meaning of the pins? The left side (RIN,LIN,FR,FL etc.) is analogue input/output, the meaning PA3, PB6, PB7, PD2, R0...3 are not clear. TX/RX surely for terminal connection.

Cheers,
Bernd

Hello everyone,

I have recently acquired a pair of electrovoice sentry III and i love how it sounds. The cabinets are in rough shape but can be refinished. These are the smoothest horn speakers I’ve heard.

Anyways, I was told by the seller that the woofers have been refoamed using cerwin vegas. They work and sound good but i just had to check if the drivers are original as was advertised.

So i removed the woofers and found that the cone has been patched up. I’m not really familiar with speaker repair/ reconing do i wanted to ask here if the job is acceptable or garbage and if i have to have these drivers reconed. As they are at the moment they sound good without distortion even if pushed hard.

Need advice on what needs the be done.

Thanks

Attached are some pics.

Best wishes to everyone

Hi,

For a preamp, what is the purpose of the 4.64K series resistor on each input signal before it enters the amp circuit first valve?

Does it have to be there, why 4.64K and could it be slightly different value etc.

Thanks,

Check out the build that appears in Everyday Practical Electronics Jan. 18.
A worthy build.
200W RMS into 4 ohms, 135W RMS into 8 ohms.

All information available here.
EPE Magazine January 2018

Article first appeared here: -
New SC200 Audio Amplifier - January 2017 - Silicon Chip Online

ak4497eq has a LDO regulator inside. That LDO is only for digital internal circuits ? Or is it for analague circuits too ?

Hi, I bought one of these to be used in a simple design using the Tectonic Elements 65 BMR. So far I've been pleasantly surprised, I have no way of measuring the response accurately but it sounds pretty good. I'm planning a pair of V2s so I have the option of using them either as a pair or just one for mono. I would like to be able to change the name and I've heard other people have managed to access things like EQ settings on boards that look very similar to mine. My question is what do I need to do this? I have literally no experience of things like Arduinos etc. I'm on a Mac but could probably borrow a PC if I need to. Many thanks

I need a little help in trying to figure out how to correctly troubleshoot this amp. One side of the outputs (Leftside) are completely shorted. I pulled the P12PF06 and P14NF06 FET's. Amp still would not start. So I pulled the other side, the amp runs now. I have a neg and pos rail voltage of 25v.
I am using the MRD-M501 schematic, seems to be very close. I am not sure how to check for a input signal as well as a output signal on the IC501. Any help would be appreciated.

Hi,
First post in this section.
Does anyone has experience with such beast?
Tuba HT
There is a pair for sale near me.
Shared album - Uchro Nian - Google Photos

Hi all

I have been sent this CD player to return to working condition as opposed to sending it to the skip. It starts to play well enough, however, after a random amount of time it ceases to play, displaying a 0 as the track number.

Ejecting the CD and re-inserting it starts the player again. Once playing it has continued for over half an hour, skipping forward and backwards between tracks happily.

I serviced the mech, cleaned the microswitches, replaced the laser and belt. All things I've done many times on other players and with the notable exception of a couple, this has been all that was needed. Those that didn't work had a couple of 1,000uF/10V caps bulging, so I replaced those and voila!

Even though none of the electrolytic caps on the 5240 looked suspect, I replaced them all anyway. Still to no effect, the problem remains. I've also checked for excessive heat in the components after it fails and there is none.

When it is playing it sounds absolutely fine.

Any suggestions very welcome to bring this smart little player back to reliable life.

Hi,

I’m looking for a service manual or schematic diagram for a Musical Fidelity X-24K dac. Musical Fidelity X-24K D/A processor | Stereophile.com
I want to replace a few things, and it would be easier i I had the schematics. Started out to make a schematic out of the PCB layout, but it’s time consuming an requires a lot of patience 😉

B.R. / Mats

SOLD SOLD AUDYN Copper 2.2 capacitor

You can look at the specs @ Parts Express . There big caps, to big for my spot.
They were 99$ each.
99$ for both ,plus shipping
thanks Rick

Electrolytic Vs polyprop capacitors

I have searched and not found an answer either here or in the musical instrument section.

I'm building a Fender Champ clone, a very basic guitar amp with 6V6GT for the power section. The amp has a number of 8, 16 and 25uF caps in there, now the supplier of the kit supplies electrolytic caps for these positions, but I've been building passive Xovers recently so anything upto 60uF I automatically go for polyprop caps out of habit because they are what I have been using for the Xovers.

What would the effect be of replacing these larger value electrolytic caps with polypropylene equivalents? I'm building the amp chassis from scratch so space isn't an issue, there is only a few of them so cost is not a big worry.

what is YOUR opinion, will their be any improvement in the sound, would I loose any character of the amp etc. I'm not trying to make a carbon copy of the amp, just a decent small all vale amp with a good tone.

When adding a .01 cap across a switch to suppress arcing, what is the proper voltage rating of the cap for 120 vac line voltage?

So I've been back to thinking about line arrays, and how to get better bass response with them without resorting to ridiculous amounts of boost. Wondering if there is anything like this idea here to have the opening of a horn go floor to ceiling? Not sure how it would work, perhaps a couple of large drivers inside the main part of the cabinet, with an array of tweeters at some point inside of the horn? I was thinking this might be able to help have better off axis response?

or perhaps a line of full range drivers inside the horn with some sort of exponential taper to it? if it were sized right, maybe could make up for the falling response of the array on the high end, and at least remove that EQ hurdle?

construction could be either stacked MDF/plywood, or better would be to cut slits and bend along its length, since stacked wood that high is asking for trouble. Not sure how to get the drivers inside, but an access panel on the front might allow for the to be put in on the inside of a baffle facing the horn.

This is probably a crazy idea, but maybe it's a stroke of genius? I was originally thinking that it would be a way to have a relatively large cabinet for a bass to mid speaker that would feed the sound out alongside a floor to ceiling array, or symmetricly along both sides of an array of tweeters placed in the middle of the horn opening.

Amp powers up and plays audio but I have to have the gains maxed out on all channels in order to hear audio .


I’m getting rail and regulated voltages .


Any ideas ?

Dear diyaudio-community, I am, or to be more precise a friend who hasn't got an account on here, is in need of your help!
He told me few days ago heartbroken that his beloved Creek Destiny 2 integrated amp shut's off every time he turns it on.
Sadly I am not much help when it comes to Creek amps since there is too much going on inside of there for me, or to phrase it differently: I would at least be able to take a closer look at it if I could find a schematic or service manual for the amp...


While talking to him I found out the following: 1) the amp is arround 9 years old 2) it never had any problems despite a bit of very quiet hum, but he thinks it's his dirty mains 3) the amp is faulty since he turned it on one day and it automatically shut off
While skyping with him I also told him to just unscrew the top without touching anything and only show me how the amp looks inside and as far as I can tell there are no visibly damaged parts which I find curious but it could be that a transistor, mosfet or sth else is damaged but just not visibly...or maybe it's just the amp being too sensitive/protective since there's more protection circuitry in there than I have ever seen in an amp. Has someone maybe got an idea how the protection circuitry can be "reset", if that is even possible since leaving the amp unplugged for some hours and than turning it on didn't help.



The amp now behaves like follows:
When he turns it on the standby-light flashes as normal, than the speaker B-light also starts to flash and finally the flashing of both lights stops and the red error-indicator light, turns on and stays lit.
-Just as a side note he also already tried turning the amp on with just the mains-cable and the speaker-wires hooked up. Again no success, but at least other components can be ruled out now.



Please help him and tell me if there's something I would be able to check or if he should send the amp straight to Creek for repair.
Maybe there's DC on the output or the bias is somehow too high, but I won't touch anything in there without a schematic but identified to pots per channel which are probably for setting bias and dc-offset, but again I'm not certain which pot is for what.


Help in any shape or form and guesses what the issue may be are greatly appreciated!
If you know someone I could contact regarding the issue or schematic, please ask them or tell me how I can get in touch.




Much love,
Brzzl

I did this last night when I was getting some popping noises after trying out a few things on my amp as one channel had become lower than the other. When I was done I still had popping noise so I pulled out the can of Deoxit and gave all the sockets on both the pre and power amp a spray and made sure to get the pins cleaned too. I was done for the evening so I didn't wait around for the stuff to dry and left it for morning.

Well today I turn it on and the system sounds better than ever. It was if I changed a meaningful component or put silver cables or any number of other tweaks that improve the sound.

You just don't think to do it as a means of improving the sound, rather it is to fix a bad socket. You wouldn't put an old oxidized cable into your system so why allow the sockets to be in that condition? Now I know!

Oh, the channel imbalance went away as did the popping noises, so it did fix that too.

I assume this is 9v zener? It is all orange with black stripe and A2 letter on one side and 9 number on the opposite. Used in accuphase p-102 front end voltage regulator. Measured voltage drop is 1,6v. Strange. Please advise, no schematic available




.

Hello everyone, this thread to share my experience with two genuine Electro-Voice DL15W recone kits (part F.01U.110.893) bought from The Speaker Exchange(reconingspeakers.com)
EV Electro Voice 15" DL15W Recone Kit F.01U.110.893 - Speaker Exchange
I received the 2 kits in perfect order (but bulk not on an EV box), fit them on my EV DL15, break in at 20Hz during 6 days... and then test on DATS v3:

Where I should get an Fs=21Hz, Qts=0.16, Qms=4.38 as specified on speakers data, I measure Fs=31Hz, Qts=0.28, Qms=11.21 on the DATS... Qms is 160% out of spec...
It’s not electrical, only mechanical: the Mms is correct but the Qms is too high (+160%) which indiacte that spider and/or surround is too stiff, even after break in.
then a question: are theses cone genuine EV ?

I contact The Speaker Exchange about that, the answer is:

I’m sorry you are disappointed in the parts you purchased. However, I can assure you that we sent you the exact parts that we purchased from EV. New parts can never be compared to old parts because there are often some changes. This is across the board with all brands
Off the top of my head, can come up with many reasons that the specs might not match up exactly to your old speaker: changes in production of the parts, incorrect reconing (setting the voice coil too high, too low, too much adhesive, etc), problems with the wiring, crossover, cabinet, terminal, etc.
Again, we absolutely, definitely, 100% sent you the parts that EV sent us. We do not lie about our listings, nor do we ever make changes if needed without notifying you first. Frankly suggesting that we lie and cheat is extremely insulting when we bend over backwards to be clear about what we sell.

I can hear EV sell parts which doesn’t match exactly my old speakers, but they stays around the specifications range… In my case, the Qms is 160% higher than it should be, i don’t think it’s in the EV margin…

3 pictures bellow:

PICT 1 is genuine EV F.01U.110.893 cone

PICT 2 is an aftermarket DL15W cone

PICT 3 is The Speaker Exchange received cone

What to think... PICT 3 cone seems very close to PICT 2 ans sadly not to PICT 1

Hi folks,


Being that this is the area for full range drivers, can anyone tell me their thoughts on Audio Nirvana's Super 8 alcino plus? I am looking to buy these. They run about $1,600 bucks so Id like to make sure I'm making a good purchase.


I'm also looking at buying the AN tube amp el84 I believe. From common sense audio it runs about 600 bucks.


I listen to mostly soft jazz.


Thanks in advance.

I am in the final stages of completing Troels Graveson's Ekta Grande design with the 5 degree tilted baffle and for the 2604 tweeter. I decided to enter Troels's crossover design into LEAP's Crossover program, which has response curves for all the drivers, and it does not yield a flat response, with a fairly regular increase from mid to tweeter. You can see this on the attached file. Just to clarify this is simply the crossover and drivers, no enclosure.

What I am wondering, is it reasonable for me to assume that the response will flatten once on the tilted baffle? I would like to trust the design, and think about tweaking the crossover once the drivers are installed and wired. What is my best strategy?

Good morning!

First post here so please be gentle! I'm in the process of building an intercom system for my car, using the Peltor headset mentioned on the subject. As a newbie to all this it's proving harder than I thought.

The system should also be able to use normal smartphone type headsets. This part I have more or less sorted by using a TPA111A2 headphone amp to drive them and a simple NE5532 based electret preamp.

Back to the Peltors. These have a TP-120 TRRS connector, Tip + Ring1 are for the mic, and Ring2 + Sleeve are for the phones (L+ & R-, R+ & L- respectively as it only plays mono signals). The only way I've managed to power these to an acceptable volume is with a PAM8403 Class-D amp, making use of the balanced construction of the headset. This works ok, however I feel I shouldn't be needing a Class-D amp to run these. According to the specs these have 230 ohm earpieces. Any input on how to power these properly is welcome, surely a PAM8403 should be total overkill for this?

I have a power supply section providing both 9V and 5V through low dropout voltage regulators.

My more pressing issue is the microphone. The specs state the following:

MT7 MICROPHONE
Type: Dynamic differential microphone
Frequency range: 70–9000 Hz +/- 6 dB
Sensitivity as lip mike: 4 mV/220 Ω
Impedance: 230 Ω
Noise suppression: 12 dB at 1 kHz

It also has a balanced connection on the jack (I think? Mic+ and Mic-), however, there's no ground pin like there would be on an XLR plug. I've tried all sorts of things and the only way I've managed to get anything out of it is, weirdly, with the circuit for an Electret mic as the one used for normal headsets, with Mic- as ground. I feel I'm missing something obvious here, any input is welcome.

I apologise for not posting diagrams as I haven't got any to hand right now, but I'll try to update in a bit if the conversation requires it.

Thanks in advance!

Hi to everyone!

Do someone have the CROWN XLi 3500 schematic? I have searched in the web but found nothing about!

I appreciate any help with this schematic.

Thanks
opacheco

I have a beginner question.
I replaced the bias filter caps in my dynaco pas with standard insulated axial caps. The capacitor bodies are touching the the chasis and the metal clamp on top of them, just like the old ones and it got me to thinking....


is it bad practice to put insulated caps in contact with chasis ground?
Is the covering on the components enough to safely install them like this?

I tried to place an order at ESRC yesterday and didn't get an invoice right away like normal. Tried calling today and went straight to voicemail and voicemail is full.

Anyone had any recent dealings with ESRC? Is Stan taking a coronavirus break?

Anyone know more?

I was told about these Stereolith Loudspeakers by a colleague today, and he assures me that for 60Hz and up, these things are magical in terms of imaging and depth.
It seems that the latest model is running stereo lows/mids drivers, and a single mono tweeter arrangement.
Anybody have experience of these ?.

Eric.

I have an old pair of Boston Acoustics HD5's with rotted foam woofer surrounds lying around for past couple of years. Always been meaning to replace the surrounds... I got some new Aurum Cantus AC130F1 drivers in the other day (same ones used in Jeff Bagby's Continuum, the advanced tech redux of the LS3/5A) and I needed a box to test them in. The HD5's were a perfect fit. They actually sounded almost passable when hooked up to the stock XO and paired with the 3/4in mylar dome tweeter. So I got to thinking, what if I swapped that tweeter for a nice 2in full range driver, and active bi-amped it for a very cute little FAST desktop monitor. Cute because the boxes are 6.25in W x 9.5in H x 7.0in D.

Edit: typo the title says FR56EX but actually FR58EX.
Fountek FR58EX 2" Neodymium Full Range Speaker Driver

I have some Fountek FR58EX's (thanks to Byrtt!) lying around from the recent data collection for the Round 5 of the Subjective Blind test thread. They sound like aluminum dome tweeters but can be crossed very low as they have an fs around 150Hz. One of the nicer aluminum drivers that don't ring. The AC130F1, is one of the nicest mid bass drivers I have tested - it has a super flat response, not unlike a ScanSpeak 10F, but only goes up to 10kHz and has no cone break up peaks.

I made a small 4-side Dagger for the FR58EX (3in base x 5.75in high foam core panels x qnty 4), stuffed tightly with polyfill. I went with 4 sides to make the volume larger and to accommodate the square cutout for the tweeter. I removed the stock terminal cup/XO board and replaced with a plain terminal cup. I added a 5-way banana post binding terminals for the woofer. Stuffed the box (circ 5.7 liters) with stock polyfill and added some more for good measure.

Here is a photo showing the detail of the Dagger as mounted with the FR58Ex:



Here is a photo of the completed speaker front:



Back showing the terminal cup and binding posts for bi-amping:



Edit - update Sept 28, 2015: added diffraction control Scotchbrite pads - it really works as can be seen in measured response below:



Effect of diffraction control (brillo pads):



I used miniDSP and a TPA3116D2 amp to do the active bi-amping. Since both drivers are essentially full range with clean flat response, I decided to go with a first order crossover at about 1kHz so that the filters have lots of overlap beyond the XO point. The full range driver goes down to 250Hz easily (2 octaves), similarly, the AC130F1 goes up to 4kHz easily (2 octaves). Why go with a first order XO, aren't those kind of archaic and no one in their right mind would use it given all the nice 2nd and 4th order Linkwitz Riley filters that are so prevalent? Well, the first order XO, if done right will give me a speaker that is flat phase and transient perfect. Kind of of like a single driver full range speaker, but in this case, a 2-way that is flat phase and transient perfect. What is so great about transient perfect? Super realistic percussion and plucked instruments if recorded live with minimal post production. Small jazz ensembles sound real and like they are there in your listening room.

Here is the measured acoustical crossover plot. The relative sensitivities of the the FR58EX an AC130F1 matched perfectly, no gain adjustment was needed. There is some mild EQ to get the responses sort of close to a 1st order and to flatten the response a bit.



Here is the resulting impulse response and step response. IR is very clean with little overshoot and just a little bit of fuzz which may be reflections from the driver mount and cabinet lip. The SR is indicative of a transient perfect speaker with a right triangle shape. Dare I say it, can a Continuum do this trick? Don't think so with LR2 slopes - the leading edge is probably negative going:



Here is the measured frequency response and phase, pretty linear within a 30 deg band:



And here is the harmonic distortion:



I listened to a few songs and it sounds really good. It renders percussion like it was meant to be heard. Below are some sound clips to demonstrate the time accuracy and also vocals so you get the sense of the balance in the voicing. Change .asc to .mp3 to listen.

Square waves at 1700Hz XO frequency:


If you have some old cabinets lying around, consider converting them to a new FAST.

Update Nov 28, 2015: Stereo Pair completed.


Update Dec. 14, 2019 - a passive 1kHz acoustic 2nd order XO design for this speaker based on measurements by hdspeakerman:

I know output impedance is an important measure to the performance of PSU. But I wonder if it do have the same importance when the circuit is class A. I guess class A like single ended or even push pull topology should always draw the amount of current set at quiescent state and so there is no change in power requirement, which make the output impedance of PSU irrelevant. Is my understanding correct?

Some of you may be aware that Thiel Audio went out of business and recently had their bankruptcy auction. I ended up purchasing some of their SmartSub 1.12 plate amps. Apparently they have some serious DSP in them but I can't seem to find the software anywhere. And I'm no where near being able to reverse engineer that 🙂 I spoke with Mr. Gillum who used to work for Thiel but he doesn't have any leads. Anyone have any ideas? Thanks!

So my living room is 11x18 or so. I’ll measure proper when I get home. Listening position is facing a fireplace centered on one of the narrow walls. About 3 feet from that wall on the left is a 3-1/2 to 4 foot opening to another room, which used to be about 8 feet, but has built in bookshelves/cabinets either side. To the right is a large window spanning 2/3 of the wall. Behind is a wall with an opening about 3 feet wide, and behind that a hallway. Ceiling is 8’ tall.

I’ve been planning for some time to build a line array set a-la Roger russel to go at the front of the room. Corner array isn’t going to work, given there isn’t really a free corner due to a window in the corner of the end wall. I know these won’t go low enough for movies, regardless of what I do, so I’ve been thinking the last week or three about subwoofers. I’ve read many things, about three being better than one, etc, etc.

What I’m wondering is how low of these really need to go, what kind of SPL? I don’t want my house to rattle, but I do want to get a little more immersive for films and occasional TV watching. Normal listening level for me is 85-90db max. When things are loud. That’s measured with an iPhone app from middle of the room, but hopefully gives a decent idea of how loud I get the mains. I have plebty of amp to drive anything reasonable, and can acquire another 2-400W in stereo for $100 or so.

I’ve found drivers I can build into 1cu ft cabinets that would be $50 or so, and get me up around 100db for one. With f3 of about 30 hz or a little lower. Getting more than 103-105 at that level, and it seems I’d be smarter just to buy something for $200 like those Klipsch units at circuit city for $200. seems hard to push the sound levels at low frequency much past 105 or so without getting big cabinets or pricey drivers.

So I’m wondering how much i really need as sound reinforcement, not so much as teeth rattlers.

Hi,

I have a few items for sale that I planned to use, but never got the time.

1. ̶S̶o̶e̶k̶r̶i̶s̶ ̶D̶A̶M̶ ̶i̶n̶p̶u̶t̶ ̶b̶o̶a̶r̶d̶ ̶v̶2̶.̶3̶ SOLD

̶T̶h̶i̶s̶ ̶o̶n̶e̶ ̶i̶s̶ ̶n̶e̶v̶e̶r̶ ̶u̶s̶e̶d̶.̶
̶[̶u̶r̶l̶]̶h̶t̶t̶p̶s̶:̶/̶/̶w̶w̶w̶.̶d̶i̶y̶a̶u̶d̶i̶o̶.̶c̶o̶m̶/̶f̶o̶r̶u̶m̶s̶/̶g̶r̶o̶u̶p̶-̶b̶u̶y̶s̶/̶2̶6̶9̶9̶4̶3̶-̶i̶n̶p̶u̶t̶-̶s̶w̶i̶t̶c̶h̶-̶b̶o̶a̶r̶d̶s̶-̶s̶o̶e̶k̶r̶i̶s̶-̶d̶a̶m̶1̶0̶2̶1̶-̶d̶a̶c̶.̶h̶t̶m̶l̶[̶/̶u̶r̶l̶]̶

̶[̶U̶]̶2̶.̶ ̶L̶u̶n̶d̶a̶h̶l̶ ̶L̶L̶1̶5̶4̶0̶ ̶i̶n̶p̶u̶t̶ ̶t̶r̶a̶n̶s̶f̶o̶r̶m̶e̶r̶[̶/̶U̶]̶ ̶[̶B̶]̶7̶0̶€̶[̶/̶B̶]̶SOLD
̶
̶O̶n̶e̶ ̶N̶E̶W̶ ̶o̶t̶h̶e̶r̶ ̶u̶s̶e̶d̶ ̶b̶u̶t̶ ̶i̶n̶ ̶e̶x̶c̶e̶l̶l̶e̶n̶t̶ ̶w̶o̶r̶k̶i̶n̶g̶ ̶o̶r̶d̶e̶r̶.̶

3. Noritake CU16025ECPB-W1J VFD 40€

Both new, never used! Price for both.



4. ELMA 04-1130-20J 50€

Elma Rotary 10K switches mono, mounted with 0.1% Vishay resistors. Never used. Made per Goldpoint schematic and used exactly the same Goldpoint values. Price for both!





5. Lateral CFA 120W - BSA PCB pair 20€

Well known dadod's design. I have 3 pairs.

Lateral CFA 120W - BSA



If you are interested, PM me.

I am restoring a FET ten/pc Phono Pre-Amp and I have gone through the power supply and replaced the aging parts. I connected the power supply and listened to the amp only to have one of the tantalum caps fail and smell terrible!! I replaced the tants and the amp is working now. I want to replace the coupling caps and I am having trouble finding the schematic for this unit. Has any one gone over one of these units and replaced the signal path caps? Which are they? Thanks!

With Xmas coming up I'm thinking of a DSO for both audio electronics and digital at a hobbyist level. I'm not sure if work or my insurance would be happy with me borrowing work's lovely Keysight.

So in terms of requirements
* Audio
* Power - ie AC/DC B+/- voltage levels with an appropriate probe if needed
* Digital such as I2S etc up to 5-6Mbit.
* Small that it can be put on a shelf without taking too much space
* External monitor support would help.
* Exporting raw data would be useful - USB drive would be fine, better a live stream.
* To a certain degree happy hacking it.

I suspect that most in this price bracket probably have the same rise time, sample rate etc.

Budget ~300GBP.

So the obvious ones are:
* Hantek DSO5-series - the review on the EEVBlog seems to show a Hantek locking up and very slow.

* Rigol DS1054Z 50Mhz (4ch, rise time 7ns) £309 with a bit of hackery gets 100MHz (300vpk CAT I)
Clock jitter: EEVblog #699 - Rigol DS1054Z Oscilloscope Jitter Fix Testing - YouTube

* Rigol DS1102Z-E 100Mhz (2ch, 1 GSa/s, 24 Mpts, 8 Bit, 1.75ns rise time) for £250

* Siglent SDS1202X-E 200Mhz (2ch, 1.8ns rise time) for £300v (400Vpk CAT II)
EEVBlog YouTube: EEVblog #985 - Siglent SDS1202X-E Oscilloscope Teardown - YouTube
This thread doesn't look too promising: Thread describing compensation issue

Hi there!

Short background:
I'm new on this forum and also quite new to vintage audio. A year ago I bought a NAD 319 in fairly good condition. More recently I have also bought a cheap NAD C370. Both are experiencing some issue at the moment and I would like to try and repair it myself. Hopefully you can help me!

NAD 319 - Partial power on after re-cap
After one year of happy listening, my NAD 319 starting fading on the right channel. This happened over the course of two weeks until almost no sound was coming from it. I figured it had to do with the caps on the PSU board so I replaced all of them. Now it turns on, but no power comes on the tone control and volume control board. I can hear the relay clicking though.

NAD C370 - Loud turn-on thump / pop
My other amp has all of a sudden the amp started to produce a loud pop on the left channel when I turn it on or off. Some pop was already there, but it was very soft and seemed normal.
The pop stays when I plug in a headphone jack.

If you can help me troubleshoot it would be great! Happy to provide more answers or photo's if necessary.
Thanks in advance.

Cheers,
Shiftie

Jensen ISO-MAX transformers (isolators)

1 x PC-2XR Pro-to-consumer isolator (XLR to RCA)
PC-2XR | Jensen Transformers
100 EUR

2 x Jensen Transformers DM2-2RX (RCA to XLR)
2-Channel Output Isolator (1:1 Output Ratio)
100 EUR each

Picture: Dropbox - IMG_8190.jpg - Simplify your life

Regards
Micke, Sweden

SOLD!

Change of plans for me. Will not build my Valve DAC (DSD-only variant).
Selling circuitboards and suitable R-core transformer.

Info about project in thread Valve DAC from Linear Audio volume 13.

• DAC PCB (all SMD parts in front/back of the circuit board installed)
• Filter PCB (pair)
• R-Core transformer, never used (Primary 235V, Secondary 250V, 2x15V, 9V, 6.3V)

Price: 200 EUR + shipping

Pictures
Dropbox - IMG_8237.jpg - Simplify your life
Dropbox - IMG_8238.jpg - Simplify your life

Regards Micke (Sweden)

SOLD!

A pair of Klipsch K402 horns as a complete set: 402 horns, stands, and 2 pair of drivers:

1) Klipsch K-69-A: were in use for a couple of hours and need to be broken in further.
2) Radian 950 Be PB: Beryllium diaphragms, 4" voice coil, 2" exit, neodymium. First owner, these drivers were bought on sept 22, have +/- 120 hrs on them and are just broken in.

Condition: as good as new
Original packaging available.
I'm located in Belgium, shipping in Europe only.
Reason for selling=WAF. These horns were in use in our living room, if I had a seperate listening room, no way I'd be selling these.

Shoot me a reasonable offer and we'll see what happens...

Not sure if this is the correct forum section to ask in but here is my question:

I want to archive my SACD's onto a hard drive and have most of the solution as I have an Oppo 203 with Vanity HD card that gives me AES outs on all channels converted to PCM and an interface into my computer so I can get all channels into a recording software but this is where my knowledge ends!
What software would I need to record the 5.1 channels into a recognised file format for playback. I realise this will be a real time recording and I won't have separate tracks etc. but I don't know of any other way to rip an SACD? Any advice gratefully received!

I have some 6V6L Valves for sale if they are of interest to anyone.

Looking for £75 for the Quad, delivered in the UK, ROW is extra.

Dear Friends,

I have recently bought the KT88 genalex gold lion and 6sn7 Tung Sol for my Dynaco inspired project. I have a question regarding the sockets used for the lamps.
I have seen some ceramic China made sockets or old Soviet ones for 3 USD. The manager from the shop from where I got the tubes told me that they were crap and I should buy more expensive ones from him (14,4 USD each: Керамические ламповые панельки CMC8G Ceramic Gold, купить-гнездо под лампы)
Since I need 7 of them, the difference in costs is significant.
Can you share your experience? What sockets would you recommend?

Anatoly

It's occurred to me that it's possible to create a software tool that will take the LTSpice model for a tube and create an optimal linear input-output load line. It could also be used to take a given load line and find the most linear load line position.

Has anyone done this already?

I was thinking of creating an Octave (free Matlab clone) tool todo this in a Jupyter notebook. Only issue is Octave is single threaded so may be a little slow.

If I create a 4096x4096 grid I can approximate quickly - not many people need more than 0.1V or 0.1mA accuracy so that would perfectly well.

Then it's a case of finding the flattest linear line across for the given Vg.

I was after some help wiring this transformer, I'm pretty new to this, so please keep it simple.

I've never wired one before and wanted to check before wiring it (Audiophonics last photo). I'm in the UK, so 230v is what i need.
Blue- neutral terminal
Red- positive
Connect orange and white together.

On the output side to get 12v connect grey and orange together for negative and grey and orange together for positive. Does that sound right?
linear power supply convert - Google Photos

Is ZD4901 a 15 volt zener ?

At what point is it clearly advantageous to go to a 2-ounce copper weight on your PCB manufacture rather than the standard 1-ounce?

Hi Guys,

Have a Sonic Frontier SFD 2 dac board which am finally going to resurrect.
The input receiver is dead. Original idea was to run I2S to bypass the input
receiver all together. Currently the filter is a NPC 5803 apt. I'm aware that
a German company that sells an adapter board for this conversion with the DF1704. From data it seems that the DF 1704 is able to receive I2S signals
right, so this would solve one of the headaches. The other is since I'm going through so much hassle to resurrect the dac , are there better digital filters out there ? Thanks in advance guys. I know it's an oldie but it's a good one which is
such a waste if I just leave it aside

Hi hope someone can help my understanding here. I am repairing a Cambridge Audio A1 mk3 fitted with two tda1514a chip amps. The two rail fuses were blown so I powered up through a DIM bulb tester. It indicated a problem (bright 100w bulb). I removed the two chips and found one had significant low ohms between supply pins and others. The other channel did not have shorts. I put the suspected good chip back in circuit and powered up. All ok this time with current draw and fuses but I checked the dc offset voltage across the single channel speaker output. Bearing in mind only one chip in circuit which I didn’t think should matter, I am getting 2.3vdc at speaker terminal. I haven’t tried speakers yet but this doesn’t appear correct. Am I missing anything in my understanding or do you think the second chip has an issue also.
Many thanks
Mark

Best Full-range driver for enjoying classical chamber music at low volume.
















Alpair7MS sound in YouTube
Forqueray cembalo - YouTube

PC(Win XP home,32bit)
TOPPING E30(DAC)
SOFTONE model7(300B single)

I have an old ailing power supply stepping up the voltage on my electrostatic speakers. It's potted in wax and given the time/effort required to get the wax out, create a jig for the connectors, then return the wax and set the connectors properly, I'm looking to make some upgrades/replacement of old parts while the wax is out.


The Selenium diode on one of the supplies is failing. The repair, using readily available parts, is a chain of three 1N4007 diodes. What, if any, would be be superior alternative to this three diode chain? Cree Schottkey diodes, hexafreds, etc?

Any suggestions or ideas are appreciated. Thank you.

Hi, I am used to building guitar pedals but want to start building studio gear. In particular I want to start with building a One Knob Gain/EQ Control as an outboard gear which can accept a line input and returns a line output. The signal would be coming in from a line level instrument or sound card and back into the sound card input. My experience with guitar pedals using them as outboard gear indicates that in some cases a reamp box with an isolating transformer is needed before the input because of ground loops which result in noise. Thus my question is: When building outboard gear such as my mentioned idea, is an in-built reamp box required to be added at the input or what is the process usually? Since I mentioned my concern with noise I fear that leaving the input without any form of 'reamping' will cause ground noise.

Hi folks, I am designing an pre amplifier circuit but could not find any 6.35 mm jack socket in my local stores. So how could I connect my guitar cable without this socket also without soldering any jumper cables to it?

Has anyone experimented with using an IMS (insulated metal substrate) pcb for an output stage (ie the aluminium-core single-sided pcb used for power dissipation in LED lighting etc). Many packages like TO220, TO264 can be modified for surface mount by forming and trimming the leads I suggest...


Effectively IMS contains its own thermal washers built in and reduces mounting hardware requirements. On the downside it makes the whole OS harder to repair.


For FET output stages it opens up the possibility of using compact SMT packages such as directFET.

Got these little CHP-70's from Scott they are sitting in the box playing at low volume for the moment about 100 hours so far but even now I'm loving them. What boxes to build?

Im going try small boxes I think as reason was to build something small for use around the dining table.

Slim Classic GR dKal-El70.3 0v81 Mark Audio CHP70.3. with ACA and dcb

http://frugal-phile.com/boxlib/P10free/CGR-dKal-El703-301113.pdf

Vocals and mid range sound sweet other system in main room is 10p which I also love so looking forward to comparing.

Thoughts?

Hi, I have a Hifonics mono amp BRZ1700.1D with a capacitor problem.
Actually I think a lot of the older amps have the same problem.
BP CAPACITORS, they now only make 100v or less non-polarized (BP) capacitors.
My amp has four 100uf 160v capacitors and one 22uf 250v capacitor.

The board is actually mark for polarized capacitors but that's not what's used.
Its C201 202 203 204 if that helps
I would like your opinion on what to do.

1. Use two polarized caps to make one non-polar cap 2 200uf 100v capacitors in series
to make 100uf 200v capacitor and use to replace the 100uf 160v capacitor x 4

2. Do the same but use non-polarized capacitors.

What do you think would be better 1. or 2. ?

Film capacitors are to big or cost way to much to be a option as far as I can tell.
Or can I just install normal polarized capacitors the the right value?


Thank you for any help

Hi folks - having spent some time unsuccessfully parsing the filters on RS, Mouser and Digikey, time to turn to the forum for help.

I was looking for a low Vth aka logic-level beefy power mosfet to use in a Cap Multi. The majority of thruhole parts i found were To-220. While not essential for my project, i wanted to look for and try to look for something in a beefier package for (possible) reliability benefits.

Anyone any ideas ?