Hi all,

I have a little bit of decision paralysis at the moment due to not finding a product that does exactly what I want.

The MiniDSP Flex seems like a nice little unit (if not a bit overpriced) but only accomodates for a stereo pair of two-way active crossover speakers. I am hoping to be able to scrape together a third pair of channels and I wondered if any of my proposed configs would come with any negative impact. I already have a MiniDSP 10x10 with a stereo/2 channel SPDIF output so it got me thinking.

1. If I run a SPDIF signal into the 10x10 SPDIF in and use one pair of its DACs/filters for the woofer I could then route/daisy chain the SPDIF straight out untouched to the SPDIF in on the MiniDSP Flex and use the stereo pairs for mid/tweeter. My reasoning is that it's a bit more important to have the mid and high with lower noise and distortion and the 10x10 is a bit long in the tooth now.

2. Split the SPDIF source and run parallel DSPs.




https://www.minidsp.com/products/minidsp-in-a-box/flex
https://www.minidsp.com/products/minidsp-in-a-box/minidsp-10x10-hd


Would there be any degradation after the source signal has been upscaled by the 10x10 only to be processed again by the Flex?

Any thoughts and opinions are welcome!

Cheers! 🙂

No idea where to post this.

It's Saturday at 3:30 and I'm listening to Shostakovitch's Lady MacBeth opera from a PBS FM station in the web. (Pretty nice.)

And I'm thinking I bet I could always tell a fresh live (or near-live recording, like I'm hearing) of an opera from a regular "stale" recording.

Clearly there are coughs and noises as a tip-off. But footsteps have a reality much better than commercial recordings. I think? So clear. Great spatial location. Just wonderful.

My speakers are crystal-clear electrostatics.

My imagination or does a mountain of interposed processing hurt the sound on commercial releases?

Ben

Hi,

Wondering what schematic you would be suggesting to drive a pair of ESL57's?

I have a single ended EL84 based integrated here that sounds quite good, but could use just slightly more power.

Would like to work around an EL34 based unit. (Have all the parts here for one of those)

If the EL34 is wired in triode mode, I think the 5 or so watts could work well for my needs as I do not push the speakers at all.

Thank you for your thoughts!

P

I have just acquired Rola 66 tape recorder and am considering restoration. One thing I want to do would be to change tape speed. My unit was made to run 7.5 inch/sec and I would like to change it to 15 inch/sec. To do that I need to change the thickness of the capstain shaft. Does anyone have Rola 66 that runs on 15 inch/sec and could measure capstain shaft and post that measurement.

My offer are LDA ultra low distortion amplifier DiY kits at a non-profit price until further notice. I've advertised them at a few European Ebay sites so far.
Condition for non-profit price: send me photos of the completed amp that I can post on my homepage.

All kind of distortions are surely much lower than what can be sensed by human hearing (e.g. 1kHz THD<0.001%). Several prototypes were built and all function perfectly. ABX blind tests and nulltest. No "sound of its own", neutral and transparent. Can be used as reference amplifier or measurement amplifier, too.

LDA MIN: 2x80 Watts stereo with turn-on thump muting via a mechanical relay (mechanical relays may somewhat degrade distortion), no protections. 75 EUR + shipping.
LDA DM1: 2x120 Watts dual mono with full protections via ultra low distortion solid state relays. 140 EUR + shipping.
LDA DM2: 2x200 Watts dual mono with full protections via ultra low distortion solid state relays. 178 EUR + shipping.
LDA MON: 1x200 Watts mono with full protections via an ultra low distortion solid state relay. 90 EUR + shipping.

All components are from reliable source. Critical components are from renowned manufacturers.

Outside of Europe shipping costs may be prohibitive. The above prices include Ebay commission and currency conversion by Paypal. Currently on Ebay in the UK, Germany, France, Spain, Italy. If you're interested and the kit is not listed on the Ebay of your country, please write me a private message.

More information: Euraudio
LDA home
Please check what is included in the kits and what is not.

Good day
I have an Advent 300 receiver that I'm hoping to use for a shop amp. I bought it not knowing its condition. I plugged it into the mains via a dim bulb and was greeted with a serious hum and the bulb didn't dim. My first thought was power supply and I replaced the filter caps and the bridge rectifier as it looked as if one of the leads was fractured. This didn't reduce the hum which persists at the same loudness whether or not the volume control is up or down. I tried removing the bridges between the pre amp and main amp - no difference which leads me to believe the main amp is the problem. I can't leave the amp on for long as it'll blow the speakers (I'm waiting on some 8 ohm resistors to load the speaker terminals) so that I can more easily test thoroughly. I get a reading of 157 mV at the speaker terminals. Should I be looking at coupling caps?
Regards John

I started a thread about this project here: https://www.diyaudio.com/community/threads/oh-no-another-mullard-4-30-thread.372200/page-2

I am downsizing my system and will not pursue the project.

For sale are the pairs of Lundahl PT and OPT intended for monoblocks, along with my designed PCB's and BOM.
The BOM is all premium parts and components, included very closely matched Mills MRA resistors, Takman resistors and RelCap RTE Polystyrene Film & Tin Foil feedback compensation caps.

The PCB's are untested, but follow very closely the original CB board layout.
You can also skip the PCB's and build it P2P.

Transformers cost around $750 and I've got another $300 in the PCB's/components (so total of around $1050).

I am asking $800 shipped for everything.

I have some Pass H2 boards on the Yarra format now available in my shop.

https://www.etsy.com/listing/126160...677&click_sum=b83346b4&ref=shop_home_active_1

More info here: https://www.diyaudio.com/community/...hpa-for-melbourne-db-group-buy.334457/page-62

hi..it's possible to add a digital out at my alpine ute-92btin order to bypass internal DAC?

Hi guys

I have a Jeff Rowland model 1 power amp and it keeps blowing the one of the internal fuses whenever I start it up after it's sat overnight. It's the same upper LH fuse every time and after I power down the amp and replace it it's fine until the following day when the cycle repeats. Once the fuse is replaced I can run it all day, turn it off and on with no issues.

It started doing this after I bypassed the passive crossovers in my Martin Logan electrostatics and running them active. I can't find any schematics on this amp and the manufacturer doesn't have much interest in responding to my emails.

If anyone can help fix this annoying problem I'd appreciate it. I highlighted the fuse in question.

First of I did search for answers.
Sorry if its a silly question.
But the audio world seems to like wound wire.
So can an inverter transformer be used to power an AMP ?.
I have a 1Kva, 2Kva and 3Kva old inverters. Some are 12 volts. Some are 24 volt and some are 36 volt. i.e. the D/C power to them is 1,2,3 bats. And it converts this DC into a/c as a power backup. I just saw these with each side having 5-6 wires coming out of the transformer and was thinking if these could be used in reverse i.e. we feed power in and get d/c out the other end. The problem is while they can support huge loads. The 12 or 24 or 36 volts that go to the bats for charging are typically only an amp or two.

Another Coil I have tons of are HT coils. i.e. The ones you connect to your spark plugs. You have two types CDI which is very low primary like 1 ohm. But high secondary 8K
And the other type is TCI which has high Primary and secondary winds. Like huge bottle coils.

Any idea how any of this stuff could be used in the Audio world ?. Im doing a steampunk setup. Having a few HT coils and UPS transformers would look cool lol.

5 PCs of the Magix2 isolators

sizes are —4”/100mm high unloaded. 100mm barrel Dia. 75mm plunger dia.
each pod can support 12lbs.

bottom ring allows adjustable height

$875 for 5

Looking for a little more info on the Norelcon AD4877 magnet. All the data I can find says magnet is Ticonal VII (steel?) 30% more powerful than alnico. So what is Ticonal VII? Anyone have any experience with them... any good, just ok, a waist of time?

Also looking at Sonido SFR-200a, same questions (other than these are alnico)? Are these hard to ship to USA? Canada outlet?

Comparing all of these to MarkAudio 10p, which I like a lot, just wish they were alnico.

Hi to all tube experts out there. Im building triode dick design pushpull 807 amp exactly on dicks plan but I run in some problem. On the driver stage that Im using 12sl7 tube the top triode section(one half of 12sl7) is working without problem, the bottom half(triode) make me problem becouse I mesure on the cathode 0 volts. So the top triode I have on anode 365volts before 180kohm resistor and 210 volts after 180kohm resistor so direct on anode, on cathode I have 2,4 volts and its all OK. On the bottom triode I have 365 volts before 180kohm resistor and 360 volts after direct on the anode and on cathode I have 0 volts. I checked 5 times all wiring, I put two pairs of another 12sl7 tubes in there and the problem is the same on both channels. So plese look on the schematic. Is there some error in the schematic or I made some mistake?

I have 4 lightly used Hammond 154B chokes for a lower current Class A amp power supply. Worked well in a MiniAleph.

Asking $35 including shipping.

3mH, 1.5A , 140milliohm DCR, 4 oz.

Leads are about 4-6 inches long.




I will ship USPS Priority Mail to Continental USA only.

SOLD

For sale are some overseas sourced boards.

- pair of Mini Aleph signal boards, built up and tested.
-pair of bare Mini Aleph signal boards
-pair of bare Mini Aleph or similar Class A amp power supply boards

Asking $30 including shipping to Continental USA

We have just been watching "Repair Shop" which is a maker/fixers type of show here in the UK. One of the guests brings in a record-radio from the 70s and my wife then says, my mum has an old radio that's mine (essentially he mum would like to make space) but it doesn't work. Queue some searching of the images the mum sent and hey presto.

It's a Phillips H4X73A. A full tube radio and record player in a single cabinet: https://www.radiomuseum.org/r/philips_h4x73a.html



Needless to say - I'm very interested in getting my hands on it!

Has anyone worked on one?

I purchased small modules from sellers like compindia, HNH...It was a very bad experience.
The comp... I ordered 433MHz Tx/rcvr and they sent 433MHz tx and 315 rcvr. Sent him so many messages.
HNH,,,sent 2 ch remote instead of 4 ch I ordered. Another headache...messages, phone, messages and all they do is bluff
Again HNH... sent an used faulty item. Same headache for this under Rs1000 item they keep giving excuses and bluffing and bluffing.
Total waste of time
Gajanan Phadte

Hello,
i have removed 2 suspicious resistors from an amplifier and PSU board. One is open, one is tested at 3.8M with my DMM. So almost open i think.
The problem is the colors of the bands, they are not easy to read. I see 2 golden bands, 2 white bands, and maybe a purple (passed) one, what do you see?
They are each one connected from the output of a full wave rectifier(+ and - 50VDC), and to the center lug of a voltage regulator (supposed to give + and -15 VDC) and also to the center lug of an unknown transistor. That's all i have.
Many thanks helping me to decrypt these resistors...

Complete with all parts, less the original box. Tested works ok. This is audio only with 3.5 jack or optical output.
Shipping within EU preferred. Asking price 50 EUR + postage.

I've got couple of old decks with limiter. The limiters are interesting but the release is too slow to make it usefull in a studio. Is there a way to mod it for faster release, maybe adding a pot somewhere? I'm not really sure how these limiters work but with faster release I can see a potential for compressor use. Anything I can do? Thanks for advice

Hi, i am making lm1875 bi-amp. One for tweeter and one for mid-range. Does anyone knows the best circuit scheme for this?

And also do you know some scheme for active crossover around 3kHz?

Hi everyone! These are my first DIY speakers. For about a year I read forums, watched videos, chose drivers. And I decided to make the main mistake of a beginner, I did not choose a ready-made project, since I did not find a project that would suit me.


Tweeter - Viawave SRT-7 . In queue, will be ready soon.

Mid - x2 .Kartesian Wom120_vMS 4.5". Purchased, I already have 4 pieces.

Low - "Noema 300GDN39-8" Purchased, in the process of delivery. Very budget 12" russian driver. Approximate the final price for x1 - $93. This driver doesn't have a good reputation in the russian DIY community, but my budget made me believe on him.
My budget is very tight, so I couldn't afford a good 12-15". There were several options, but my intuition told me to choose this one, even though I don't like the idea of the driver with a large x max parameter (+-12 mm). But I liked its powerful magnetic system and the low weight of the moving part (though a small voice coil, 2"/5 cm).
I bought UMIK-1 microphone.
So far I am planning DSP on PC with ASUS Xonar U7 MKII via Jriver or EqualizerAPO may be. The problem is that I often watch YouTube and a little delay will annoy me.

I thought for a long time TM or MTM. I still could not decide for myself which option would have more advantages, but I decided for myself that if I don’t try MTM, then I will regret and think, but what would happen if .. Moreover, I have 2.4 meter ceiling without processing and laminate on the floor. Listening distance 2.5 meters.

My dad already had an amplifier SMSL SA300 - $130. I couldn't think of a better option with digital volume control for the same price than asking him to borrow from him and buy 2 more for $260. Yes, this is not a very good amplifier, in the future I will make a DIY amplifier on ready-made boards

I came back to listen to my old PCM2707/1794A DAC which I built few years back, and I was amazed that I could not hear any difference in my now upgraded system (RMI-FC100, Dynaudio Focus 340, ZD5) between Denon DVD2900, Cambridge Audio StreamMagic CXN, Topping D50, and my old DAC. Moreover, I have yet to hear a difference between high res material and good ol' 16/44 recordings. So here we are again, another stab at immortal PCM2707/1794A reincarnation, simple and awesome (to me at least🙂.

I hate mixing SMD and through hole, so it's all SMD 1206, still manageable by old school guys like me. All power pins are cleared by TI LDO regulators and there is separate Microchip ClockWork clock pumping beats into PCM2707. No capacitors in signal path, thanks to TI voltage inverter.

https://sites.google.com/view/dacgear/xr-dac

Anyone any experience with these

I have this old TDA1541A-based DAC lying around and hope someone is able to share its schematic. Here are some pictures.

And can anyone explain why there are two inputs, marked 5V and 1/5V?

I picked up two Quad 303 amps recently and am considering using them as “monos” into my ESL’57’s. I’m not going to strap them for more power, but thinking of using a single channel per amp. I guess all I would need to do is remove one of the output boards of each amp.

I don’t think anything else would need to be done. Would there?

Had the good fortune to find a boxed set of the 9 Beethoven symphonien for $5 in a goodwill shop.
Very good condition, a couple of fingerprints easily cleaned. Its a Deutsche Grammophon, Berliner Philharmoniker, 1970 edition and the toningenieur (recording) engineer Gunter Hermanns. The result is easily much better than any of my CDs more recently recorded from the same mob. Spacial presence and bass much more alive and most instruments identifiable by my old and abused ears. Just like being there. I put it down to being an analogue process start to finish.
Anyway, if you should also find a copy of this vintage grab it.

Hi, my first post on here as I'm really new to DIY speakers despite building my first pair about 8 years ago (haven't built anything since).
I have however slowly accumulated a collection of drive units with the plans of building some more speakers as I thoroughly enjoy the first set I built.

As far as I can tell the normal process is: plan, buy, build...
I've gone a bit backwards (budget constraints and taking advantage of good second hand deals) in that I have bought, need to plan and then build
In summary I have:
3* seas excel w18nx001 8 ohm
5* vifa m22wr-07 6 ohm
4* peerless 830493 HDS
& 9* vifa dx25tg-05
Many of the drivers I don't have any TS for, so I have invested in a dats V3.
My loose plans are 2* 3way pairs 1* 2way bookshelf pair and a 3way centre style but any advice or suggestions would be greatly appreciated. I also had a play with the Dats v3 on my first builds (2way sealed cabinets) with the impedance sweep (attached). I would appreciate it if someone could point me in the right direction where to learn how to interpret this.
Many thanks in advance

My latest project is another SIT follower amplifier. You may have noticed that I favour SIT followers, since I had built a 2SK180 choke loaded follower and a THF-51S CCS Mu Follower common drain amplifier, and now I am building another SIT common drain amplifier. It's just that in my system, the SIT followers sound the best. After listening to the followers, I realized that the single ended common drain SIT amplifiers that I had built in the past had a bit too much harmonic distortion. With followers and their lower distortion, the music has a clarity that I did not hear from my common drain amplifiers.

The two latest diyAudio Sony VFET amplifiers designed by Mr. Pass are also followers and are much loved by their owners, so another VFET follower amplifier can't be a bad thing. This will be a bit different, being choke loaded instead of Constant Current Source (CCS) loaded.

I decided to go with choke load for a few reasons. Deciding factors include low power dissipation because the choke dissipates very little power, unlike a CCS. Therefore I can re-use my 22VDC power supplies since the choke drops very little voltage, again unlike a CCS. And I really enjoy the sound of my choke loaded 2SK180 follower amplifier, so another choke loaded follower is welcomed. The lower heat dissipation will be appreciated when I use it in the summertime. Also by choke loading, the build will be very simple. There are not many parts. The amplifier circuit board will be very simple, with a resitor or two, a Zener diode, and the VFET. It will be mainly used to provide connection points for power, bias voltage, input signal, and speaker out wiring. I will have a board for the bias supply, but the input and output coupling capacitors will be chassis mounted. My Luminaria preamp has enough voltage output and low enough output impedance, so a separate voltage gain stage and an input buffer are not required.

As mentioned the choke load drops very little voltage, allowing an operating point of 21V Vds and 1.5A Iq from a 22V power supply. This operating point is similar to that of the diyAudio Sony VFET amplifiers. The typical 18V power transformer and 22VDC power supply that is used in many First Watt clone amplifiers can be used in this amplifier. The diyAudio power supply would need a modification since V- is not required. The V- half of the board would need the capacitors repositioned so that V+ is outputted, allowing each half of the supply to power one channel. It would be nearly dual mono with only the power transformer primary shared by the two channels. So if you have a pair of Sony VFETs and an unused amplifier, this amplifier can be quite easily built.

I will be re-using the chassis and power supply of an existing amplifier that started life as a Hammond 193V choke loaded VFET L'Amp, and then repurposed to accommodate a F2J. This new amp is reminiscent of Michael Rothacher's L'Amp in choke load configuration, except this will be common drain instead of common source. So it is back to the beginning for the chassis.

I have ordered the parts that I need, and they should arrive tomorrow. So let the build begin!

I'm fixing up an old car with my daughter- a 1989 Volvo 780. It was fancy back in the day, and had 2 amps, one for the front and one for the back (along with a very awesome looking graphic equalizer).

Everything works fine except for the rear amp. I removed it, and on first inspection noticed a burn mark. I desolder the remnants of a D600 transistor, order a replacement (KSC2690AY, close as I could find), and stuck it in. I also find some cold solder joints on one the large caps, and resoldered them. All the other components seem to be visually ok.

Hooking it all back up, the "remote-on" light- which is the only light on the thing - lights up dim with 12v hooked up and car off. Remote on is sending voltage, but there is no change. Makes no noise or anything.

I have some very dusty electronics experience - I used to repair arcade games - mostly just replacing components-, and I still do a a lot of stuff with microprocessors, so I know my way around a multimeter and soldering iron. This low level troubleshooting is a completely new thing for me, but I'm prepared. On top of it the amp design is strange, with all the connectors crammed into one side.

Where should I start? Thanks!

-rj

Greetings. I am working on a church PA system that uses two Tannoy v12hp plus a Tannoy 15-inch sub. "v12hp" is different from "v12" and different from "vx12". One of the v12hps seems to have a bad LF driver. Indications are: first, there is an obvious lack of midrange (i.e., between the sub and the tweeter); second, there is no DC continuity at the speaker terminals and a two-way crossover with a good driver should have this. We need to rent a lift to access the speaker. (The DC continuity measurement cited above was taken at an accessible point on the speaker's cable.)

I've got a few ideas on how to fix this. All comments and recommendations are welcome. Maybe someone he3re knows where to get a replacement cone, driver, or entire v12hp?

Alternative 1: replace the LF driver in the Tannoy v12hp, I can't find a replacement driver. This implies replacing the HF as well since it's a dual concentric.

Alternative 2: Recone. I can get a reconing specialist to do the repair. I don't know where to find a recond kit. Would need to rent the lift twice.

Alternative 3: Replace LF and HF drivers in both v12hp cabinets. The Radian 5312 plus Radian crossover has been recommended as a replacement (I'd need two sets to keep the speakers matched). If the low-frequency fbox is wrong and/or the Q comes out wrong for these replacement drivers, I can stuff the box. Since I'm using a sub I hope I can cross over to the sub to avoid any such low-frequency issues.

Alternative 4: Buy a v12hp on the used market and put the working used driver in my Tannoy enclosure for appearance sake.

What damaged the driver? I think it was the old dbx driverack pa and its well-known power-down thump. I've taken out the old driverack and will get a driverack PA2 (any other recommendations?)

thanks,

Tom

I've done searches on

Tube & Test & Set & Calibration
Mercury & 1000 & Tube & Test & Set & Calibration
Etc....

Anyone have any suggestions on calibrating a Mercury 1000/2000 test set?

I've got the schematic, user manual, etc.🙂

No calibration info though.😡

Thanks.

Steven

Hello everyone,
I came across eight new 6384 tubes in my stash of stuff. Anyone have any experience with these or should they be eBay'd

Thanks
Ray

Hello!
What are the advantages and disadvantages of TL compared to BR?

Learn how Chris Brunhaver became the speaker designer at PS Audio as well as the process for his first creation known as the Aspen FR30 Loudspeaker.

Login to view embedded media

Who can upload the service manual of this model ?
some URLs for reviews and various internal images:
https://audiolife.pl/yamaha-a-s1100/
https://de.yamaha.com/de/products/audio_visual/hifi_components/a-s1100_g/features.html
https://jp.yamaha.com/products/audio_visual/hifi_components/a-s1100_g/index.html
https://www.lifewire.com/yamaha-s1100-amplifier-1846255
https://www.lowbeats.de/test-vollverstaerker-yamaha-a-s1100/

P.S.: Service-Manual from Yamaha's power amp model "M-5000" is here:
https://elektrotanya.com/yamaha_m-5000_pwr-amplifier_sm.pdf/download.html
https://de.yamaha.com/de/products/audio_visual/hifi_components/m-5000/index.html
same circuit topology for the power amp unit than A-S1100

I picked up these horns online, took a risk because the seller didn't have published specs, they are either extras from a large order or cosmetic blems I think (the flange where they bolt to the cabinet was curled up a little but screwing them in corrected it).

Anyway, I've tested one and I'm very pleased, balanced frequency output and excellent control of dispersion (at least where I hoped to have it, not much focus of 500hz!).

But one thing feels off, even if i didn't hear an issue in my I initial test... the rear face of the phase plug has a lot of odd topography (see pic). Should I fill the crevices in? The white part is just a pvc cap tucked into the plug, otherwise the driver would have been firing into a half liter cup. But should I worry about the more subtle crevices? Also the white part is inset an eighth inch or so. Maybe use bondo? It's a medium-hard plastic.

SOLD


I have 2 Bartola Valves SiC bias boards each with 6 Cree C3D01060 SiC Schottky diodes mounted. Heatsink mounted also, but not really necessary. You can solder on 2.54mm jumpers to decrease bias voltage in 1V increments.




Asking $24 including Continental USA ground ship.

https://www.bartola.co.uk/valves/for-sale/sic-bias-boards/

Hi everyone;
I want to build a pair of subs to match my La Scalas. Strictly music. I am a skilled carpenter and I want a higher end driver, I don't want a driver with super high xmax. something fast with little distortion. I want to build a box designed for a specific driver, it can be any size. Any thoughts? and I did see a similar thread here but didnt give much info

I have weird problem. I am restoring an old sony reel to reel. I can remove the front, and work on belts and mechanical stuff, but i need to open the back and work on electronics too.
Problem is, i can't get the back cover off. This is embarrasing, but it seems like noone has ever removed the cover. I took the screws of, but there seems to be cover nailed to the wooden frame together. It looks like u shaped nails. Does not seem like easy way in.
Anybody has any experience with this? I thought removing back cover would be normal part of service.

Hello
I'm trying to make a 2-way project with a crossover:

Speakers:
1. Vifa DX25BG60-04 (4 Ohm)
2. Vifa NE180W-04 (4 Ohm)

Case options:


~20-22L

Cabinet project:
SEAS "The Mimir"

Based on the project:
2way bookshelf and crossover



I created a project, but I think it's not perfect at all:






Do you have any ideas what could be improved here?
THX

Being a hopeless luddite, I am clueless about the last 10 years of development in windows hardware and software.

I am looking to buy a reasonable 2nd hand laptop to do audio measurements as mentioned in the title. Otherwise i will use it mainly for web/email/officeapps.

I have an ancient digidesign mbox 2 that i would like to use for acoustic measurements, if possible. What's going on with audio drivers these days in windoze land? Asio4all still a thing? 😅

Was thinking about a second hand Lenovo, maybe a T480.

Here are links to a couple of local vendors:

https://tkvfinland.fi/product-category/tietokoneet/kannettava-tietokone/

https://www.teraset.net/product_catalog.php?c=105


any opinions, advice, warnings, insights highly welcome!

Best regards,
Bob

Not sure if you guys have heard off this s/w called Peace check it out. Its the most comprehensive EQ I have seen. I use it on my Media streamer / player.
And now this fresh blog post from the author.
https://sourceforge.net/p/peace-equ...e-called-bard-for-equalizing-your-headphones/

And if you want to try out Peace here is the download link.
https://sourceforge.net/projects/peace-equalizer-apo-extension/

I have a pair of Townshend Glastonbury 1 speakers and the bass/midrange driver is damaged.Replacements are unavailable as are spares.
These are two good to bin having very well made,incredibly well damped cabinets with nice ribbon tweeters.
Can anybody suggest suitable full range replacements for use in a FAST configuration.They should take an 8 inch speaker with very little if any cabinet mods to make them physically fit.

Down, From sx : dual chanbel softstart kit n. 2 ; n. 2 amplifier in kit MX50SE ; n.1 class D amp TDA 8950 100 watt. High Power supply switching 500 WATT 28/35/45/50/55/60V; n. 2 class D amp 25 watt tda 7492 and n.1 class D amp Y148 15 watt

Great subwoofer material
I sell in bulk 100 euros shipped EU

Hey all I'm wondering if anyone took some really good pictures of the schiit magnius circuit board. I've seen the one on their site and one other that is a little more zoomed in, but still at a high angle. I'm especially interested in what that cap is doing on the output of the tap6120a2 chips and also if they are using more or less the schematic in the data sheet or if they have done anything special. Especially with the opamp side of things.

Just in case anyone's looking to offload, for a pair of speakers I'm building

Hi everyone. Im new forum member, Im looking to repair my Heco Victa 500 with new tweeters. The old ones have burned out 2 times and and look very cheap. Im not willing to put them again so im looking for 2 new and must be matched and product at least the same quality of sound (why no better). Im from Greece...i could give 40-50€. Any suggestion??? (and sorry for my terrible english..not my first language..i will use ebay to order them..i think) And some photos which maybe help you with suggestions (last pic is dimensions cm*). Thank you

Is the JBL Live 460 NC worth the price?

Need help identifying these Soshin caps. There are no markings on the yellow cap themselves, just the printing on the wrap. Any help would be appreciated.
Thanks

Hello,
I purchased a Kemper Power Kabinet which is a guitar cabinet with a Kemper Kone (Celestion IR Speaker) and as I found out an IcePower 300ASC or 300AS1. I actually got a replacement because the original was making a continual clicking noise (either constant, or sometimes with a repeating pattern), but the replacement makes the same noise.

Here's a video I made of the issue:
Login to view embedded media
Any ideas what could be causing this clicking? Is it something in the design, a failed component, or something in my power system?

The surprising conclusion to this video will be that I blew it up by shorting the optocoupler...sadly I shut the video off 5 seconds before the smoke got let out :'(
But I'm still curious what might be causing this, and if I can manage to repair the board how I could fix this too (or if it would happen on a replacement 300AS1 or 200AS1)

Thanks for any and all ideas!

When I saw ZV9 for the first time it looked to me like a beautiful preamp topology made to an power amp thanks to existence of LU1014.
Few months ago I started to entertain this single ended preamp idea again and not only that the sound was exceptional (I like it so much that I removed BAF 2013 preamp from the case to move this one in although I thought that I'll keep the BAF2013 for a very long time), it showed other great qualities too: great drive/swing capability (Zout less than 50R and ability to drive power buffers like F4), great versatility in terms of gain and power supply used, low and steady consumption (10-12mA per channel), it's stable into reactive loads and the freq./phase response is linear up to 100kHz.

The story about this preamp actually started here but I think it deserves a dedicated thread. The main change from the original ZV9 is that I use gyrator instead of aleph CCS - it sounds better to me but it's easy to test both.

As a power supply I use 32V SMPS taken from dead HP inkjet printer, followed by a capacitance multiplier. The PCB is 74 x 25mm, copper side view. R9 is mounted on the output terminal and C3 (WIMA-MKP10) is beside the PCB due to its size. C2 is 2-5pF, made from two twisted isolated wires cut to length for best square wave response (I did this just because I don't have small value caps in my parts repository at the moment). As shown, the gain is 13dB (4.5V/V) but can be set as ratio of R1/R3 in a wide range (I tested 6-26dB). The clean swing at the output with 30V rail voltage is 24V peak-to peak (8.5V_RMS) into 10k load.

EDIT:
One thing I forgot to mention - due to RC constants present in the preamp and cap. multiplier, 10-15 seconds are needed for capacitors to charge and the sound starts to come out. You might call it: very slow start 😀

JensH said:

I don't have access to test equipment that can verify this low level of jitter though.

Click to expand...

Hi.
To measure phase noise of crystal oscillators by using two generators.
Signals from the test oscillator and heterodyne oscillator are fed to the mixer. The difference between the frequencies of 20-40 kHz generators optimally. The signal output from the mixer is input to the sound card. The figure in the upper window, the spectrum of the signal of the crystal oscillator in the lower window range phase noise. Alternative to expensive devices for measuring phase noise.

Anyone have any information on the Fostex Laboratory Series T825 horn tweeter?

I've not found anything particularly useful online, hints of efficiency in the range of 102dBSpl, and that they sound good is about it.. I plan to cross at around 8kHz.

They are not quite efficient enough to keep up with my woofers and am planning eventually bi-amping mids and highs partly to get around this and for other reasons.

I recently purchased one of these little gadgets, a handheld solid state recorder with 32G memory and rechargeable battery.
It wasn't expensive and is surprisingly solidly build and heavy for its size. It records various flavors of MP3 and Wav formats. I got it to use with some little mics I made, some of which are worn like earbuds. It was meant to be a very light and easy thing to carry for field recordings and such. But it failed to work - maybe.

When I did test recordings, I found that using the internal mic, only the left mic is recorded, nothing from the right. The left mic is recorded on both tracks, nothing comes from the right. So I tried with the external mics plugged in. Nothing but the left mic recorded, but this time the left mic wasn't routed to both channels. Then I tested Line In (there is a software switch) and got perfect stereo flat from 20Hz to 22kHz both channels working as they should. The left channel recorded on the the left track, the right channel recorded perfectly on the right track. Hmmmmm......

Since the PUI mic capsules I have put out a whopping good level (too much for the mic input) I tried the Line In setting with the mics plugged in. It works! But again, no signal on the right. Even though from the computer line level signal the right side recorded perfectly. If Line In works on both channels with an input from a line source, why does using the same setting with mics result in recording only the left channel? This had me puzzled, so I had to drink some rum and think about it. Some of you will have already guessed the problem.

It occurred to me that the problem had to be the mic power. To power the mic capsules "Plug-in-Power" uses a 3V bias on the line. Maybe the right side has no 3V. An input from a computer or other line source doesn't need the 3V to function, but the mics do. What if only the tip of the 3.5mm plug had the 3V bias, and the ring didn't? Sure enough, that's the case. 3V on the tip, nothing on the ring. That's both in Mic and Line settings. That means that if I can get 3V to the right side (ring) of the connector, the right external mic will work. But how? I'm not even sure I can get the thing apart. Then I have to figure out how not to get crosstalk thru the 3V supply.

Any ideas?

i get the picture from local service
he use very cheap driver about less than $10 for woofer and less than $10 for tweeter BUT he dont tell the brand and type

This is my first "from scratch" design and I'm hoping to get some feedback before I make any serious mistakes. I put "from scratch" in quotes since I certainly drew inspiration from many other designs posted here and elsewhere (particularly from Pete Millett and John Broskie).

I built a pair of 300B P-SET monoblocks last year and have been thrilled with the sound, but I'd like to have a bit more power and try something different. The SET amps were based on the ANK Interstage kit with lots of embellishments (a couple photos attached), but using the basic circuit design and transformers from the kit.

So this will be my first tube amp build without starting with an existing design. The attached schematic shows the basic amp circuitry that I'm currently planning. My goal is to get 55-60W class A1. I don't need a lot of gain since my DAC and Preamp can easily source several volts. I'm planning to use a CLCLC supply for the 425V B+ (currently using 220uF caps and 4H chokes). The gain/driver stage will use a Neurochrome Maida regulator to supply regulated 300V. I'm planning regulated DC supplies for all the filaments.

The output stage bias will be controlled by a Tent Labs Negative Bias Supply, so each of the 100K resistors will connect separately to this controller.

I'm planning a power supply controller which will power up the filaments first, then bias controller, then the B+. This will run off a 12V power supply which will also provide a -12V reference (using a separate regulator) for the LTP current source.

My current choice for the OPT is a Toroidy 2K with CFB windings. I'm going to use these windings to provide symmetrical feedback to the input stage LTP cathodes. I will probably incorporate a couple switches to select global feedback level and triode vs ultra-linear output tube operation. I've read that toroidal transformers can work very well for tube OPTs as long as there is minimal DC imbalance, and from what I've read, the Tent Labs bias controller does a good job with this.

I've currently selected a 12AX7 for the gain stage. I'm not sure if this is the best choice, but I wanted something with enough gain that I could avoid two stages. If anyone has suggestions for other tube types to consider, I'd appreciate it.

Thanks.



Below are a couple photos of my 300B PSET monoblocks completed last fall.

SOLD

Two new in package 6-24 Biamp crossover kits from the DiyAudio Store

Asking $25 each shipped to the Continental USA.

Each includes the board, bias resistors and fets, you supply the rest.

They retail for $49 each plus shipping.

...ever been done? - got a bunch of old cone tweeters I want to use....

Hello,

I am selling my rare and in mint condition (both sonically and cosmetically), SONY MDR CD3000 headphones, which includes its proprietary case.

This is really a one time opportunity to these in such condition and for this price.

Please see the pics included in the post.

I am looking for 380€ + Shipping (please PM me for quotation).

I accept Paypal with no extra charge.

Thanks for looking.

4x 0.33uF /600
8x220/100v
Pio caps must be recent edition. I will probably have to buy a new ones but who knows . People " change directions all the time.
Other kaisei caps needed 220uF/ 500V and 470uF 16V

Pair of SB Acoustics Ring Radiator Tweeters. One was not soldered and the other soldered tabs in great shape, see pics. $75 pr plus shipping TBD. Paypal preferred.

Looking for a Woofer Tester Pro in good condition. Please PM me if you have one for sale. Thanks

Hi everyone. Just looking for 2 NOS pairs of driver transistors for my Luxman L30 - 2 X 2sc1626 and 2 X 2sa816 . Hoping to get them locally in southern Ontario . Any leads ? Cheers, Mike.

I've just done my first test with the PA loudspeakers I'm building. I only built one to start so I could assess before making the second pair of boxes (one for the tweeter horn one for the mid horn).

I was pleased with the sound so far (more fine tuning to do but I'm in the ballpark just adjusting levels between the drivers), but I'm not sure how to assess what I'm hearing. What should I be listening for in terms of if the enclosure on the mids is too large or small, or not airtight? Distortion? Sound emanating from the back of the box? Is there a reading I can take? Does it effect frequency response?

I'm especially curious if I'm taking full advantage of the horn loading as it's currently configured, but no idea how to assess that.

Looking for a pair of Alnico Betsy. Prefer USA to keep shipping prices down. Would consider a Sonido, if one was stateside.

So I want to switch out my Kenwood stereo with a JCPOWER audio system. I removed the old wires and was careful to not cut any of the car wires. I noticed that there was wires cut off ND I bought Scosche FD213SD stereo connector. While I was wiring the wires of the new stereo to the Scosche stereo connector my friend said I was doing it wrong and I had to match one out of the 3 that fit the car . So I am very confused I thought I was suppose to use all 3 connectors. And I wanted to see if I can just wire the new stereo connector to the car wires without the Scosche FD213SD connector?
Thank you.

Hi Gurus,

Sorry for this newbie question.

I am trying to build a class ab amp powered by SMPS sold in Aliexpress as I want to try SMPS to power the mono amp.
It uses 2 pairs of to3 output and im currently using 600va transformer.

Given that the transformer has 35-0-35ac after bridge rectifier estimate: +49, -49Vdc, then can tap to 0 ground from transformer center tap to amp board ground.

I just wanted to check if this SMPS attached will work?

What do I need to ask the seller? Should I ask for a +50vdc, -50vdc, with 0 ground or should a go a little bit higher like 53-55+/-vdc,+0 ground?

Will it just be a direct connection to the amp circuit board? just connect +50vdc, -50vdc, then the 0 from SMPS to ground of the board?


Thanks in advance.

I recently got a cheapie 2nd hand JVC amp. There was a fairly quiet but totally annoying treble hum coming through the speakers at all times. It didn't matter which input the amp was set to or whether there was anything besides an output connected toit. The hum was especially apparent when using headphones and would make my head ache after a while.

I searched online to see if anyone had the same problem, and only saw one post on another forum with no replies. I decided to fool around with the amp a bit and see if I could make the hum go away.

Open the case and there is a secondary circuit board mounted above the main one in the back right corner. That's the AM/FM tuner. I found that by disconnecting the two black ribbon-like cables from the board, the intereference disappeared.

So! It would seem you either have to live with the hum or give up the radio tuner. I do not listen to the radio with this, so it was a perfect solution for me.

Now the signal to noise ratio seems very reasonable. There is only a faint hiss when the amp is turned up all the way, beyond where it would ever be during use.

This is just here as a reference, for anyone else with this otherwise decent amp. (I would have replied to the one post I found on the other forum, but I couldn't register with any of my email addresses )

Good morning everyone ! Did Nelson Pass design a class D amplifier? 🙂

Hello, I would like to understand better what happens on a speaker with high EBP if it's placed in a sealed box. I know that the lower end of the frequency response is going to extend less and is going to drop with something looking like a 6db/octave filter unlike vented one where the drop if sharper. But given the fact that the lower end is not needed is there any other disadvantage in doing so? I would think that this would be a way to lower low frequency distortion in high output lvls without using a high pass but from some experiments it looks tome like the linear movement of the driver is increased for the same lvl of playback at the same frequency.

Hello, if someone have schematic for this device or scaned circuit diagram can send me to mail or post here. Thanks

For sale
Black gate std 220uf/50 (4pcs)
A bit used, legs short
50€ all, shipped in EU

Black gate pk 47uf/25v (10pcs)
Never used
50€ all, shipped in EU
Payment bank transfer or PayPal
Mail for contact:
luccicottoatgmaildotcom

For sale
4 x lme 49713ha
50€ shipped
4 x lme 49710ha
50€ shipped
Payment via Bank transfer or PayPal
Mail contact:
luccicottoatgmaildotcom

A pair of Sony 2sk82 , original from Acronman
Rank kd33
Mounting plate and Kapton isolators

150€ shipped in EU
Mail contact
luccicottoatgmaildotcom
Thanks
Marco

Hello Everyone,

I was given an older HIFI stereo radio, an Unitra Mercury. https://www.radiomuseum.org/r/diora_merkury_dsh_303dsh30.html
The PA uses STK-077 Sanyo hybrid chips, those are 20W amps, running from +/-21V rail voltage.
The output DC offset is bit more than I would like to see, those are 100mV and 85mV respectively, with no load, after about 15 minutes of warming up.
I do not want to replace the chips, I am thinking about adding offset adjustment circuits, like the Pioneer SX-1250 has.

Any comment on this?

Thanks, Peter

Will be switching up to 5V signals - negligible current. Probable only set/reset a few times for initial conditions. Need 1 and 4 SPST "poles"

Thank You

Oh, and if this type of switch is NOT recommended - are there any kind of Thru-hole headers or something with say the pins soldered to the board and some kind of a "slide on shorting stub". Probably commonplace but I don't know the terminology