One of my 18BR40 has developed a rattling noise when playing 20-80hz at moderate levels. It seems that the rattling follows the excursion. If i lightly touch the cone while its playing, the rattle goes away. The pitch changes slightly if i adjust the bolts holding the driver in the box. The rattle is barely audible when the driver is in free air. I have two that has been used as subs for the past 8 years or so, only one of them have started making the noise.

Any ideas what this could be?

A guy who works as sound engineer and tries to repair stuff on his own.

I have:

• 4x RCF 8004AS
• 2x RcF 705 Subs
• 2x RCF 932a
• 4x RCF 310a

-…

But I am not happy… because i want something deeper.

In the past I built some 2x12 subs and different 18“ subs but just BR and never Horn. So maybe I Have to change my mind?

Best regards

Up for sale set of luxury raw mic cable from Canare, quad-type, with 4 conductors! instead 2, what allow to supress typical noises greater, and keep highs pristine.
Also cool to wire studio devices, mics, drumsets/orchestras, etc.

Rare offer: colorful set just at once, with no long previous ordering & waiting when you order from dealers.
5 colors 10-12m each, ~55.28m total.

Manufacturer site : https://www.canare.com/analogaudiocable

Type : L-4E6S

Dia: 6mm

Wires dia: 24AWG

• brown
• grey
• white
• amber
• green

Pic of black cable presented to see cable design more detailed, not included in set.

Price lowered from -$250,-
Now: 55.28m - $210,-

FREE shipping across EU/UK.
Items will be packed carefully with international tracking across all distance.

---
Also for sale other items, some presented here, small items can be added into box:

• Grayhill 2, 3, 4 decks, single shaft rotary switches, up to 2x6, 1x12 poles
• Mogami W2944 pro audio cable, 2.5mm, 8 colors, ~235m
• high voltage mica caps, 1000-5000V, Airvox, Sangamo, Sprague
• Triplet ultra rare 4.5 inch VU meter
• different Marion meters, 2 and 3 inch
• Triplet mains distributor for USA plug, 120V, 10 sockets

* * *

Up for sale set with 10 pcs (min quant in any combinations) luxury JBT toggle switches (USA made), never used :

• LL123 - single row contacts, two positions
• LL223 - dual row contacts, two positions
• LL232 - dual row contacts, three positions, attention pls, type ON - ON - ON between rows

Need for hole 6.5mm.
One of most attracting features - shaft locking, with prevention sudden toggling.
I.e. you need pull shaft to toggle shaft from position to position.
Other feature, aluminium head of shaft can be unscrewed off and anodized, or painted/varnished into desirable colors.

All time kept in soldered original manufacturer plastic bags in normal stable store temperature.

Price - $79,-USD, FREE shipping across EU/UK.
PayPal payment way is possible with some specific.

Items will be packed carefully, supplying from Ukraine with all distance tracking.

Items also can be bought how mix sets in any combination with listed above, or with some other my items, see below ⤵️
starting from total $80,-.

Also possible for sale, can be put into common box to optimize shipping:

• Grayhill 2, 3, 4 decks, single shaft rotary switches, up to 2x6, 1x12 poles
• Mogami W2944 pro audio cable, 2.5mm, 8 colors, ~236m
• Canare L-4ES6 pro mic cable, Japan, 4 wires instead 2 to supress all noises, uniq offer - 9 colors
• high voltage mica caps, 1000-5000V, Airvox, Sangamo, Sprague
• Triplet model 426 ultra rare 4.5 inch VU meter
• different Marion meters, 2 and 3 inch
• Tripplite mains distributor for USA plug, 120V, 10 sockets

* * *

Up for sale pro audio cable set Mogami W2944, Japan, dia 2.5mm, balanced or stereo.

Manufacturer site : https://mogamicable.com/category/bulk/console/

8 colors, ~29-31m each color/232m - $325,-.

Item will be packed carefully with international tracking across all distance.
FREE shipping across EU/UK.

---
See also my other items (some presented here on SwapMeet), small items can be added into box:

• Grayhill 2, 3, 4 decks, single shaft rotary switches, up to 2x6, 1x12 poles
• Canare L-4ES6 pro mic cable, Japan, 4 wires instead 2 to supress all noises, uniq offer - 9 colors
• high voltage mica caps, 1000-5000V, Airvox, Sangamo, Sprague
• Triplet ultra rare 4.5 inch VU meter
• different Marion meters, 2 and 3 inch
• mains distiributor Tripplite, rack 19 inch, for USA 120V plugs

* * *

This pre-amplifier was published in 1994 in Elektor.

https://drive.google.com/file/d/1gFx9xPYtoKBOYfyoPnygX1_ZdWmwhsKf/view

Problem is that I don't see the volume control for it.
I know it's a noob question but where to put it and what value should it be?

Hello looking forward to helping out wherever I can and understand things better 😊

Hi

Does anyone has the schematic for the above amp?.

Thanks

I've built a few Marshall style amps and always looking for that "sound" albeit it's subjective.
Always looking to learn how to improve my knowledge and skill set for building.

Hi all,

Can anybody tell me if those rectifiers are same with anode in centre pin.

One rectifier is connected to positive pin of two capacitors and same capacitors ground is connected to primary ground terminal.
second rectifier is connected to secondary ground of transformer.

Hello: Looking to purchase older test equipment

I've unscrewed the feet of my ESL57's so they can sit comfortably on top of my DIY Ripoles and they do sit there comfortably but I would like to have it all a little bit more secure. It seems quite feasible to bolt them to the Ripoles. And it seems like a good idea to use the thread already there for the rear foot.

Except, I can't seem to find what kind of thread it is! Because I am pretty sure it is an English thread, which is rare over here.

Can anyone tell me what thread I should use for a bolt that fits in place of the rear foot of an ESL57?

Thanks in advance!

Ad

I am quite a novice, but I do understand the nature of graphically drawing a load line for a triode. I have yet to find a good explanation and illustrations of pentode load lines.

Any points to good basic explanation?

Roger

I had a quick look at the RCA type 10 datasheet which didn't list maximum anode dissipation, although the picture in the datasheet showed a globe shape (which may have different specs to a shoulder ST shape short plate type 10?)

Does anyone know the maximum anode dissipation of a UX-210 globe tube (long plate)

Can I obtain the best phase response without performing measurements? If so, how to achieve it?

Also, how did the speaker manufacturers in the 70s and 80s (pre-1985) manipulate the phase response at that moment?

Hello,

I'm looking for toroidal transformer supplier in Australia for my Aleph JZM, so 300VA 18V secondaries. I read about having high quality secondary windings and am looking for advice from those who may have had experience with Australian suppliers. I'm rural and don't have a supplier close by so trying to make the best choices before the build.

So for I have a choice between
-VIGORTRONIX from Element14 with daul primaries to select between 115v and 230v AC https://au.element14.com/vigortronix/vtx-146-300-218/300va-toroidal-transformer-2x18v/dp/281770002
-TorTech, Australian manufacturer, single Primary https://www.tortech.com.au/product/toroidal-ei-transformer/toroidal-transformer/
-PowerTran from Altronics, the most pricy, singel primary. https://www.altronics.com.au/p/m5518c-powertran-18-18-300va-toroidal-transformer/

Any perspectives, would be appreciated.

Hi there folks,
I am a 'funny old fart' that doesn't own or use a Smart Phone, but I am interested to know about the sound quality people are getting
using Phone music aps + the use of Bluetooth ???
EG. Are there differences between Spotify, iTunes and YouTube?
Hopefully some people can enlighten me 🙂

Hi

Would anyone have a volume knob for a Crown IC150a preamp? Ive been looking for one in my house and ebay for years












Thanks!!

Hello
Im new to this so let me know if this is the wrong place to ask this question, thanks

JBL LX44 Midrange drive code - 405G, 5 inch external diameter, Polymer laminate cone, 8 ohm

I have a very old pair of JBL LX44 speakers and its time to change out the mid range drivers, Im not replacing the speakers as I still love them.
I have looked on the net for new ones but can only find refurbed models and would prefer to replace them with new 405G's or a different brands better alternative. I also cant find anywhere the specs of the 405G's - Frequency Response, Power Handling (max), Sensitivity etc.

Can anyone advise where I might be able to buy new 405G's or a different brand or particular speaker driver that would be a great replacement OR does anyone know the specs of the JBL 405G drivers so I can go looking for a replacement.

Thank you in advance and look forward to any help you may be able to offer

cheers
Terry

Hello,

Last Summer I currently built the following stack.

Mid Top - selenium Pas3Ma1 - x2 HP 326HZ
Kicks - Cubo Kick - x2 HP 120HZ LP 210 HZ
Subs - MHB 46x2 HP 30/40HZ LP 80 HZ


I am looking to replace my Mid Top With a MEH Synergy Horn Type. This Horn will basically remove the needs for my kicks. But I want to keep them.

should I just keep the kicks and double up in that 150-250hz range? Or should I try and structure the MEH with a HP around 300HZ and then the Crossover in the MEH to be higher around the 800/850 Range. I would not have ports if I go with option #2.

from reading If I get rid of the 150-250hz range in the MEH, then the horn does not get any loading? (Is this true?) and the MEH design becomes pointless.

Thoughts?

Thanks,

Cole

Currently shopping the 8" full range market......found these.....specs and FR are encouraging for OB/sealed and both appear easy to drive.
Found some info here and other locations regarding the Monacor; but not much regarding Teramps (I suspect they have more of a car audio following)

First the Teramps....then the Monacor

Most setups I've seen for measuring TS parameters of a driver, independently of the electronics used for the measurement, have been placing a driver with its cone firing up and its magnet sitting flat on a surface like a desk, usually with some absorbing material like a rubber below.

My question is: Does this make sense according to the assumptions used in the derivation of the TS parameters?

To begin with the driver is literally above an obstacle, the surface above which its laying.

If that surface were the floor, this would basically be laying on an a large sound-reflecting plane. It's going to be interacting directly with it.

And often I've seen the driver sitting near to an edge of the desk or bench, so it's not even close to an infinite plane.

I originally figured that hanging a driver in the middle of the room could be a good idea, until I remembered this allows its own body to move too, so it becomes more of a system like two asymmetrical masses coupled by a single spring, rather than a single mass coupled by a spring to a fixed point.

I tested this by simply firmly holding the speaker near Fs while hanging, and it did change its behavior, while simply approaching my hand didn't.

And this is still different from having something like a steel arm holding it, because my hand is very damping, it's damping the vibrations and not actually forcing its body to be fixed.

Same thought goes for a speaker over something like a damping rubber versus a speaker held by a vise on a bench, they'll be different.

Maybe the influence of those different fixation methods isn't that large, but I suppose that having the speaker over a large surface (like above the floor) or close to an edge of a large surface (like in the edge of a desk) makes a reasonable difference.

Which is the proper way to fix it?

@Nelson Pass

I own a beautifully kept Adcom GFP-750 (blue PCB) that is the backbone of my stereo system and has been for many years. It's developed a problem lately and I'm not sure what to do about it. When I use the remote to adjust the volume up or down, sometimes it "sticks" and the motor runs the volume ALL the way up or ALL the way down, and it keeps going in that direction until I physically stand up and go stop the knob from trying to go in whatever direction it's going.

Any ideas on what part(s) need to be replaced or repaired to stop this? Everything else works great.

Thanks!

I've done my amplifiers with wood cases forever and always with mitered corners. In all that time, even knowing that a mitered glue joint is inherently weak due to being end grain to end grain, never had a failure. Until now. I sent this 6BQ5 amp off to a friend who returned it as carefully packed as UPS did on the outgoing trip but nevertheless,



I couldn't effect a really invisible repair so, never needing an excuse to do some more woodworking, I started over.

This time I wouldn't shy away from the splines I should have always used but was afraid to try. I wanted something more than just a panel with a pair of 45s to make the cuts on my contractor saw and came across this: https://kmtools.com/blogs/news/miter-splines?_pos=1&_sid=ffc1adf4d&_ss=r Most of what I've seen from him always seemed overly complicated and time consuming but this jig turned ot to be perfect; simple to make and very secure. Perfect for my 77 year old shaky hands.



The box rode the fence without a wobble and the sandpaper I added turned out to be unnecessary.

The result with ebony splines in the cherry I think looks pretty good. Oh yeah, I added long grain to long grain suspender battens to the belts, the splines, just in case.



Once the shellac cures enough to wax with 4 aught, it should look even better than the original.

I have Project One Mark 1500, Looks to be exact copy of Telefunken TR-1500. I am in bad need of schematic or service manual... Thank you

Hi Guys - I have a lot of 3e Audio stuff that I bought and have done nothing with. Just want to move it on to someone who will make the project and appreciate it.

This is my first time and I hope it is OK.
Starting with:

AMP Balanced/unbalanced AUD85.00
PSU AUD75.00

Plus postage to where ever you are.

PayPal (family and friends.

Thanks

Dan

Hi Guys - I have a lot of 3e Audio stuff that I bought and have done nothing with. Just want to move it on to someone who will make the project and appreciate it.
This is my first time and I hope it is OK.
Starting with:
TPA3255 AMP Balanced/unbalanced AUD85.00
PSU AUD75.00
Plus postage to where ever you are.
PayPal (family and friends.

Great value as the price is in Aussie Dollars - these are the cheap compared with other currencies.

Thanks
Dan

Hello everybody!

My name is Daniel, and although I had my share of simple speaker builds, with low quality drivers and quite basic and unexpensive crossovers, I do not have that much experience.

This time I am going for a little more complex project, which I want to share with you guys - and get a few insights too, of course!

See ya!

Hello!

My name is Don, and I am an amp-oholic. I am here to learn more about amplifier circuitry and repair/modification, as well as just being a part of a community of like-minded audiophiles. Thanks!

Hi all,
Im a musican and home studio enthusiast from Cape Town, South Africa. I have a fairly wide collection of analog outboard studio gear, some of which I have done minor repairs to. Im interested in possibly building an SSL bus compressor clone at some point in the future but at the moment I really just need an occasional bit of advice on repairs or components.
Cheers, Nick

Hello. I am Alia. A new member.

contacted Cary and they sent a few sketches that are very incomplete

Hello

im planning to build a speaker, but on my current presonus eris e8 with silk dome tweeter i kinda hate the highs, they never sound right, they sound different with different cables/dacs but im still unhappy

what is in your opinion the tweeter "topology" (AMT, planar, ribbon, electrostatic, soft dome, hard dome horn etc..) that sounds the best/smoothest or "most silky" in terms of smoothness but still representing the original signal faithfully?

im also specially curious what you guys think of full range driver in comparison to tweeters ?

I have an older Brinkmann Balance Turntable that uses a Pabst motor for its belt drive. It is having trouble holding speed at 33.33 rpm from one day to the next. For example, yesterday the speed was spot-on. Last night, I turned it off. Today, I turned it on, waited for about 45 minutes and the speed was 33.11. Nothing else changed from last night: the placement, my electric. The speed at 45 rpm is fine each day. I use a RöNt that was serviced at Brinkmann last year and the bearing was serviced as well this year. I had the motor serviced a couple years back, but when I ask the person who serviced it, he said check with Brinkmann. Has anyone else had experience with Pabst motors and these issues?

Thanks.

Class D half-bridge amplifiers as we known to have some disadvantages. The main one is the requirement for a power supply. As a consequence of the pamping effect Hi-quality bipolar SMPS almost not available on the market, especially if you need to get a small power.

We have designed a circuit to adapt the Texas Instruments bridge power stages for use in a self-oscillating amplifier circuit. In such a case, a single monopolar voltage is sufficient.

TAS53xx, TAS51xx type chips are well suited for self-oscillating operation: they provide linearity in the of 0.2% without any special means. Propagation delay of 50-60ns contributes to the improvement of dynamic characteristics.
Even for a UcD modulator, this makes it possible to get better than 0.001% THD+noise at first watts without loss of quality at high frequencies.
Considering further of the technology, modern modulators like ncore/purifi can be easily applied to this platform. In this case the THD+noise will be below 0.001% in the whole frequency and power range.

We have made a variety of prototypes with different variations of the bi-polar supply for the modulators.
As is often the case, the most primitive one turned out to be the most effective as well.
As a result, a virtual ground source and a level shifter added.

The prototype is built on TAS5342 in PBTL mode.The block diagram of the amplifier is shown below:
Due to the peculiarities of the output stage, the amplifier cannot clipping, it simply disconnects the half-wave of the signal. but this is not a bug, but a feature 😉


Tipical performans ( modern modulator like purifi et400)
15W 4ohm real speaker, we can't measure better because our DAC/ADC is of insufficient resolution


We tried our best and fit everything into a two-layer PCB. PP capacitors panasonic are used on the output. 8x470µf panasonic FR are installed in the power main, 2x220µf panasonic FM in the supply of the analog part. OA OPA1602+ high-speed comparator TL3016 are used in the modulator, preamplifier is assembled on OPA1612.
Subjectively it turned out to be quite pleasant sounding.

The module supports 2ohm load.
The signal spectrum in the picture is obtained with the power supply for 9 dollars, 24V 6A of the lowest quality.

HI .
Do you know possibly free software that checks the hardware functionality of the USB sound card with a test?

That’s a ‘54cm port tube resonance (halfwave) not a 81 cm/3, 1/4 wave resonance , right?


(320 hz in the response shape)

Recently I saw a demo of CrossLite+ a tool to develop DSP filters. I was hoping I could ask for a free equivalent besides REW. I've looked at REW and it seems to do everything completely backwards from what I expect, and very much tied to specific DSP platforms.

I want something that lets me draw a couple of filters and examine how the filters behave in terms of phase and time. For instance, have 2 "ideal" drivers, put them through an arbitrary LP and HP filter and see what this means to the impulse, phase and group delay. I'm afraid all the wordy explanations I read are not sticking with me, so I'm hoping for something interactive with graphs that let me feel the changes.

Thank you,

Erik

Hello!
First speaker attempt - narrow and tall to flank tv and replace soundbar.

Is my crossover design in VituixCad heading in the right direction? (Should the graph look like that?)
If yes, then I'm going to start hunting for or producing with a mic the .frd file for the HiVi M6N 6" because I like the way the HiVi aluminum/magnesium cones look.

Drivers:
Tweeter: Dayton DC25T-8
Mid: HiVi (Swan) M4N 4"
Woofer: Dayton GF180-8 6.5"

Thanks for any input!

New in open factory box TEAC UD-501 DAC with headphone amplifier. USA model in silver color. I am the original purchaser and this item has never been used in any way nor powered up. Sold "as-is" and no warranty is expressed or implied. No returns or refunds. Sells and ships to USA residents only. $400 plus shipping.

SONY DAS-R1 digital-to-analog converter in very good cosmetic condition and working well. Features twin Philips TDA1541 DAC chips in an overlapping staggered configuration operating in 18-bit with 8x oversampling at 352.8 kHz. It has 2 coaxial SPDIF inputs along with a proprietary twin optical input for the CDP-R1 CD player (not included). $1500 plus actual shipping & insurance cost.

This DAC is approx 37 years old and may require some service in the future as it is vintage equipment! I purchased it second hand from an audio store in Japan many years ago and it is a Japanese domestic market item operating on 100 Volts AC. A 120V to 100V AC step down transformer is recommended.

Sold "as-is" and no warranty is expressed or implied. No returns or refunds. Sells and ships to USA residents only. No APO/FPO addresses. Shipping and insurance may be high because of an oversized box weighing 42 pounds. PayPal use will include a transaction fee. Please pm if interested.

Please PM if you have an available, used FiFoPiMa board you're willing to part with.

Rick

thanks regarding how to design this specific type of waveguide

Hi
I have been involved in the recording and audio industry for many years - hi fi reviewing alongside studio work (currently for mix engineer Spike Stent) and consultancy for some hi fi manufacturers. Ever since building valve amps with my father from an early age I've never been to far away from building speakers and amps, mostly for fun, although sometimes they have ended up being used in the studio. The process of experimenting then building, measuring and tuning a speaker project is something I still find endlessly fascinating and very rewarding, especially when it goes right -

I have a Memphis 400.4 six five series bridged to focal k2 es 165k in front. 1 and 2 to left 3 and 4 to right . Useing the passive crossovers. Question how can put the tweeters on say 1 and 2 and midbass on 3 and 4. With crossovers given with focals .

Duncan amps tube pages are down, I get this - MySQL connect failed: No such file or directory - I hope it's not Psud all over again.

Andy.

Honestly, I don't have enough knowledge to determine whether it's worth it or not, but what I do know is that when vendors add chip models to the specifications it's a good sign 🤣🤣

4in 8out about 185€ inclued shiping to EU (+import taxes) on alibaba

340€ on aliexpress all inclued..

What do you think?

I have 4 free PCB sets for GainWire MK3. This is an excellent preamp/headphone amp, a must try, highly recommended!

Original thread: https://www.diyaudio.com/community/...re-phone-amp-with-very-low-distortion.296545/

GainWire MK3 + SSR3 pcb (30 eur + shipping)
I send by post all over the world. Paymet via PayPal (F&F)

Hello from Hungary! I'm gafabo.
Welcome to the diyAudio community!
I've been reading interesting topics here for a couple of years. Thanks for the inspiring posts! Maybe it's time for me to speak up. When I was university student, I already built myself an amplifier and a DAC, after which there was a big break. Now I started thinking about building another old style DAC. In addition, I would be very interested in an SE tube amplifier, which has interested me for a long time. Just have enough free time!

Final Steps - Projects!!
VFA P FET 1-1-3.4 V3.3

Hi my name is Paul I am trying mainly to understand how audio works in general to setup my car audio system, nothing fancy but aiming SQ in general

I've decided to build a pair of subs for my son's studio, likely using a pair of 18" JBL 2268HPL drivers. The goal is low THD in vented or aperiodic enclosures, to determine the best design for crossover points higher than most typical larger subs can pull off for their size.

At first we looked at dual 12s, but none of the decent reasonably priced 12s were capable of the low distortion figures the JBLs could do from way down low to way past 100hz. The SB34NRXL is the only 12 I've used with distortion numbers closer to the JBL ($400), but one of them is close to the cost of the JBL ($340). That means closer to $700 using 2 of the SBs, for the same cone surface area as the JBL. The SBs have the xmax advantage over the JBL 2268s, but that isn't relevant at higher frequencies closer to the LP cutoff.

I've heard the JBLs in various configurations and enclosures. They are likely the best 18s available under $500 for vented enclosures and open baffle based on my listening experiences. Because of this, my son has gotten ahold of a pair of the JBLs and wanted to build a pair of vented subs, but he's also open to aperiodic enclosures if they can go down into the mid 30s using little to none shelf correction.

We'll be running these off of 1000W Icepower plate amps with very light EQ, one driver per enclosure, per side. They'll mainly be used for mixing electronic pop, jazz and acoustic music. He plays drums and is very picky about low end. The bass has to be accurate and have exceptional dynamic capabilities.

I preferred the 2268s because they have an excellent reputation and sound great in the right enclosure at just about any level. This is another trait not typical with large pro audio drivers. We looked at 18 sound, B&C and Eminence, but the JBL always won due to price vs performance.

The enclosures were going to be 6 - 7 cu ft based on the preliminary specs I have on the 2268s. I'd like to hear about some of the designs others have done using JBL2268s.

Hello everyone,

I have a pair of older Pioneer bookshelf speakers. They were probably never that great sounding, but I think they sound a little dull at the moment. They do not have a crossover, just a single electrolytic in series in between the driver and the tweeter. Can you please recommend a capacitor that is at max 10$ for one, that would bring a new life to them? I have heard a lot of praise for the film capacitors, would they be a good choice? Should the value remain the same (2.7uF)?

Thank you

I purchased this and then was gifted a Denon DL-103FL

DENON DL-103SL Special Ceramic Moving Coil Turntable AT-MS11 Headshell $375 firm

This is a special cartridge. It was produced in 1989 with a white ceramic body for a more rigid body and faster response. It takes the already great sound of the legendary DL-103SL and takes it to the extreme. It also uses a 99.9999% high purity copper wire to reduce distortion.



Thanks for looking.

Hi everyone,
I'm Tom from the UK. I enjoy fixing music related electronic equipment, especially guitar valve amplifiers. I have some experience in this area but am in no way an expert so will probably be firing a whole load of questions to y'all over the next few years!

Hi all, sorry if this is a little redundant...
I've had a Logitech Z-5500 for like 15 years now on my various Desktop PCs. I've been super happy with it overall, but we've had a wild ride together. Several years ago, I replaced the main L/R speakers with 2 small bookshelf-size that I built with help from the kind folks here, using 3" MarkAudio drivers. They sound great. The rest of the system is stock.
Recently, I've started hearing some pops and crackles (almost a sizzling static) from all speakers when there's no other output. I'm afraid the amp, or some other internal component, is finally about to let out the magic smoke.
I would like to begin investigating options for replacement. My current PC (just built), has a Creative Sound Blaster AE-5 Plus sound card, so I'm working with 3x analog outputs that need to be accepted by whatever sound system I buy/build. I'd like to use my current main speakers, and I have 2 Definitive Tech surrounds that might make good rear or center speaker(s). Beyond that, I'm looking to buy/build whatever I need. I'm not interested in going the full AVR route. I've tried that once before, and not only do I not really have the room for it, I never got the inputs and outputs to work correctly with Windows. Also, I've heard about routing sound through HDMI via my video card, but that doesn't appeal either, since it involves a 'phantom monitor', which invokes all sorts of additional issues.
I thought about something like the Aiyima A09, but the one actual review I found of it wasn't encouraging.
As for the Sub, I would probably go with a Polk PSW10, unless you folks have a better suggestion in the same general price range. I've installed 2 of those in homes for friends, and they are solid units with good sound for the price, in my 'very much not a professional' opinion.

Bottom line: I'm looking for something that will sound as good or better than the Z-5500, doesn't take a degree in electrical engineering to set up, and won't totally break the bank. I'm not 100% fixated on 5.1, either. If there's such as thing as 3.1 (L/R/C/Sub), I'd consider that as well, if it sounds good enough. My rears aren't really mounted properly anyway. 😉

Any suggestions greatly appreciated!
I actually asked this question a couple years ago, and got no response. I'm hoping this time will be better. 🙂

I was wondering if anyone here has ever built an SE amp around the 8005 or 572 triodes?
I know Wyetech Topaz had their amps some time back.
They seem like pretty decent powered triodes.

Hi,

We just got a UPV back from an extensive service @ R+S. As it's discontinued and we are concerned about how long R+S will support it for, we decided to go for the full repair option, inc. 1 year guarantee (big hole in wallet).

The machine works like a charm and has the latest firmware (good). However, when either of the oscillator options are fed to the analyser (standard oscillator, B1 or B3) there is a 50Hz spike on the FFT (it goes from below -150dBV to around -120dBV). I shorted the I/P and flipped between analogue IN / gen 1 / gen 2 - and you can see the 50Hz is not there with shorted I/P and only present when loopback (or XLR leads from I/O) are used. Our other UPVs offer -113 THD+N with 2VRMS, but the serviced one only has -111 THD+N. If I feed it from another oscillator, it's cool, so the issue is isolated to the UPV output section.

My feeling is that a shield isn't grounded or a screw has been left out - that kind of thing. I am loathe to open the thing as it has a 1-yr guarantee. I am wondering if R+S will give us special dispensation to open it, assuming that there is an obvious instruction to fix it (hence my post here, to ask if anyone has taken one apart and can think of an obvious culprit?). It would be a bummer if we have to send it back to Germany just because someone left out an insulating washer...

They swapped the entire analogue board during the repair - repair report here:

12-months warranty on the entire product

• Replacement of the Display Converter.
• Replacement of the Analog Audio Board.
• Replacement of the hard disk.
• New installation of the image and the current firmware version 4.0.5.190.

Click to expand...

The irony is that one of our UPVs was constructed out of a pair of totally broken UPVs (by us) that we bought for parts - and it has no 50Hz to worry about! We had front panel and keypad changed on the problem one, so it looks and feels like new....aarghh...

Any tips appreciated!

Mainly making vintage audio equipment restorations from time to time.
Also interested with various measuring equipment.
I think there is lot of interesting reading at DIYaudio

BR

hi

Everything tells me, that AD797 is not only a very good operational amplifier
The topology used has got to be something extremely good!

Using only the simplified schematic from Analog Devices datasheet
I get some extraordinary simulation results.
(And I am used to see a few good figures, from my own circuits. Using same transistors.)

===============================

A few details from me, for those who want to try to make a better AD797 Clone.
... but I am not sure anyone could do this better than myself
... maybe get some similar results, but not better, I doubt.

My circuit is in attachment and follows the AD797 schematic
- what I know from reading This Datasheet Very Closely

Lineup Audio Lab
AD797 Clone - version 2a
by lineup

... Supply +/- 15 Volt DC
... Test 10 Volt RMS into 2.2 kohm, = 14.14 Volt peak!!!
... Gain= x10, +20dB
... Frequency, -3dB at 600kHz
... THD <0.001%, my MultiSim does not show anything = 0.000%, see picture

Some more details:
All transistors BC550C and BC560C.
Total Supply Current 8.0 mA
Output stage, like the original biased only 0.5 mA ( 492uA more precise .... )

Click to expand...

Good Luck Fellowes!
You may need really it 😀

Regards
lineup

I am working with a Sound Stream 5 channel (Ref5.1000)m for 2 days now.It is a class AB amp. It is on protect mode, I had replaced a shorted transistor (TIP41C), a burned capacitor (10uf/25v) and burned resitor(1,2K) as shown in the picture wiht red circled, other than that i checked all the components but it seems all parts are good as far as I'm concern. What I found out was, there is no rail voltage because the TL494 PWM drive is not giving pulse signal to the FETs gates. The TL494 seems good I believed because I can see a saw tooth wave in the pin 5 and 5 volts reference voltage on Pin 14. Pin 12 Vcc is 12 volts to the ground. So i believed the TL494 is just shutting down the pulse signal output. As measured, I am getting unequal voltages on the non inverting and inverting inputs Pin 16 and 15(error amp) . Am I missing something? I did not try to replace the TL494 yet. Can anybody shed me some light on these amp. Is The TL494 deffective?

I’ve been mostly lurking in the Digital forums, learning a lot, it’s time to share back.

What happens if I "Follow" a member? Will I receive an "alert" notification if this member posts anything?

Im trying to figure out what kind of circuit can affect to q of a subwoofer system as described in the paper attached


Fig.4 Vandersteen Model Seven, acoustic crossover on upper-midrange axis at 50", corrected for microphone response, with nearfield responses of upper-midrange unit (green) and lower-midrange unit (blue), both plotted below 350Hz and taken with high-pass filter in-circuit. Nearfield response of powered woofer shown with Contour set to: "1" (green), "4" (cyan), "7" (black), "9" (magenta), "10" (red).

To the left of fig.4 are shown the powered woofer's output, with its Contour control set to "1" (green trace), "4" (cyan), "7" (black), "9" (magenta), and "10" (red). (The 11 bandpass equalizer pots were set to their central, flat positions for these measurements.) The Contour control adjusts not only the amount of midbass boost but the low-frequency cutoff. Peculiarly, the biggest response changes occur when the control is set between "7" and "10"; a light hand on this control will be necessary. I set the woofer-level control to give an apparent crossover of 90Hz, but it should be noted that there is plenty of woofer gain still available. Again, a light hand on this control will be necessary to get the best match of speaker and room.

Now that I'm finally retired from my day job, I have more time for these more interesting projects.

I've already repaired some turntables and recently acquired some cassette decks to work on.

I have to say that the restoration of the turntables was a "piece of cake" compared to these old cassette decks.

I am also interested in modifying loudspeaker crossovers to better suit my small listening room.

So there has been lot of interesting reading for me here at DIYaudio.

Markus Klug 805b Horns
Brand new
Recommended crossover is 500hz and above (cutoff frequency 300hz)
For 1.4in CDs (3 or 4bolt)
Horns are natural with cork surrounds.
25in w x 13in h x 16in d
Asking $1500 free shipping CONUS

Acoustat Answer Man - just joined this board to ask you a question. I have a pair of Spectra 11's powered by a B&K AVR-307. Sound great, like a hot knife cutting through butter.

My issue is that one speaker is definitely louder than the other. I have tried swapping channels and amps, but the issue is the same. Feels like something is missing in the sound. Is what I am describing a familiar issue? I read this thread here and it sounded similar:
https://www.diyaudio.com/community/...rostat-damp-and-subwoofer-replacement.334555/

A local speaker repair guru says they can take a look, but are less familiar with electrostatics. Is there a place in the circuity you might recommend them looking? I have another pro-audio guy coming to take a look. Trying to get these fixed in Denver, CO.

Dear fellow passionate builders.

Great to meet you all! My name is Razvan, I'm a passionate DIYer, have been building speakers for more than 10 years and I am planning something big in the coming years.

Hi all. I am a new member. I had to build some tube amplifier as SE300b, SE EL84 for myself. Hope can learn more from all of you. Thanks

I have a cross- over design and want to add another mid bass driver (so there will be 2 each channel, same type speaker) How to wire to keep it 4 Ohms or do i need to change the whole cross-over? any help or suggestions welcome

Came here to find out how to increase CM6530N PDM mic gain. In widows sound meter it barely hits 5 percent mark if I blow directly into the mic. I believe it is firmware related problem. As I read on the web there is cm65xx configuration tool to create firmware with desired configuration.
Where could I found copy of it? Thanks in advance!

From New Zealand, 68 year old body with a 25 year old brain. Always loved music and have about 1000 CDs which still get played. About to up grade my amp for a better sound but before doing that I want to upgrade my LX44 speakers which I will explain more in a forum. Love all the helpful info on this site

Thanks
Terry

Can anybody help me?
I am looking for a service manual NAD517

Hi everyone, I am from michigan and am a new member to this forum. This is my first post here to introduce my self.

Hey everyone, surprised others haven't noticed this incoming model from ScanSpeak. Textreme 1" dome tweeter. Aside from the coolness factor of Textreme (at least for the last year) what really is cool about this particular model is the low end extension and very flat FR for a low profile design. Even among SS tweets, their low profile (small face plate) models tend to suffer considerably compared to the full sized versions of the same line. Honestly wish I had this before my center channel build, I could have probably shaved an inch and a half off the height of the front baffle. 🙂



For a small baffle tweet these are some excellent results:

My amplifier is rated at 44 watts per channel, with the first 6 watts in class A. I would like to know if there is an App application to use, like a decibel meter app, to check how many watts is my amplifier putting using with different volume levels.

I tried to be as clear as possible.

Regards,

I have maranta cd63 which I modified 10 years ago with Ray’s version of the PFM flea to power a tent clock. After taking the unit out of storage, I’m getting a strange signal at the output of the clock and suspect this is the cause of the cd mechanism acting weird (speeding up like mad, with or without a cd in it). Where to start debugging?

(Can’t find a scope photo at the moment, imagine a sinusoid with sharp points)

Do you guys know a dual triode tube that can be used for a low power SE output stage?
I'm looking at say 50mA bias in class A with 20W anode Pa (per triode) max.

Jan

Hello all,
I'm a dentist in Florida who made knives for gifts, and now want to explore making speakers as gifts.
Not an audiophile. Love my little Fosi / Aiyima amps and speakers all over the house and office.

Hi,

whatelse will normally go when the output transistors of an amp blow?

Might seem like a silly question as there are bound to be lots of possibilities but i was thinking that through your experience there is a likelyhood of other components that either made the transistor blow or will have blown along with the transistor.

I have come across a few amps recently that have all got shorted output transistors on one channel and when replaced they still wont work, only the one original unblown channel works.

Suppose what i'm looking for here is a - "when the output transistor(s) blow, always check/replace ..." sort of answer.

Please help!