hi guys, i need some info from you experts. i am building a signal cable to connect my dac to the preamp. the dac has only balanced xlr outputs, while the preamp only has unbalanced rca. not to use rca-xlr adapters I enjoy building some nice cables. the designer of the dac told me that the connections, in the specific case of this dac, are: phase + on pin 2, phase - and shield together on pin 1, pin 1 connected to the connector body to the chassis. pin 3 remains disconnected. So far so good, but I came across this Ramm Audio Elite 8 signal cable, which has not two conductors plus the screen, but 3 conductors (Green, red and white(?))plus the screen. how do i connect them? two conductors on pin 2 and one with the shield on pin 1, or one on pin 2 and two with the shield on pin 1?

Hi!
sorry for yet another...
My toroidy 2 x 18V 500VA
has a earth-wire (yellow-green) accompanying the 2 primaries.
Looking through the build-guides as well as sound-au's Power Supply Wiring Guidelines doesn't show this detail.

Do I connect it to the power-connection, to the chassis before the cl60, or after (together with the PSU's ground?)
My instinct tells me to hook it up as soon after the power-inlet/switch/fuse as possible...

thanks for confirmation!

Wondering, host based Windows 10, is there a simple configurable HP filter? I am running the Peace GUI on the EQ, and just knock down the lower two octaves. HP at least 4th order, 60 Hz as my desktop speakers are 3 inch Fostex. They are reasonably flat so I don't actually use any other eq. ( modified and tweeter)

Seems over kill. Maybe it makes no difference, but I am one of those where the less is running the happier.

hi everyone, I wanted to talk about dual head usb cables construction, therefore with separate data line and power supply line. I always use for data rail a certified usb cable in order to be sure to comply with the usb protocol requirements. The power supply rail, on the other hand, I have always chosen cables with a larger section, perhaps ofc and with low inductance and shielded. What I am not clear about is the screen: on the dac connector type B and pc connector type A connected both sides, but on the power supply connector side? i usually use xlr connectors on the power supply. Perhaps it is better to choose an unshielded cable for the power branch, perhaps a quad star ...

Choosing between 3 Troels Gravesen 3way project
1) SBA 761
2) ScanSpeak Discovery 861
3) Jenzen SEAS ER



Plan to use this acoustic for a long time. Medium size room. Music(any genre), movies.


1) SBA 761 (TW29RN-B-8 MW16P-8 MW19P-8)

most advanced speaker technology (satori). What about reliability?

2) ScanSpeak Discovery 861 (D2608/913000 18W/8434G00 22W/8534G00)

newest project. cheapest. will it have the same performance as satori, or be worse?

3) Jenzen SEAS ER (CA26RFX, ER18RNX T25C003)

old project. biggest size. how it would perform compare to others?

I wanted a schme as simple as possible and a power amplifier as easy as possible to make in amateur mode.(as a hobbyist).

I used an SMPS push pull. ( with an transformer from an ATX computer power supply)

With the transformer secondary I directly in series the speaker and a solid state relay (Consisting of two NMOSFETs)

The audio PWM signal is given by an Attiny25 / 45 which also brings a lot of noise. I didn't solve the noise problem.

But I want to solve the following problem: So I use only half the power of the transformer.
When I need to have a positive voltage on the speaker, I waiting the positive pulse from the secondary and the voltage value is made of PWM duty.

I need an H-bridge-like circuit to change the polarity of the voltage, but to work and for positive voltage and for negative supply voltage.

Sure, I could put a rectifier bridge and an H-bridge, but there are too many components, I'm looking for something I can easily do.

Class D amplifier eliminated ultrafast bridge and SMPS filter capacitors - YouTube

I don't have an oscilloscope to show you the waveforms.
Calculated PWM frequency must be at 64KHz, but I didn't measure that, I just know it can't be heard.

Hello,
Everything worked perfectly until one day when I turned on my pop-up light. Suddenly, the player began to run irregularly and both the stroboscope (on/off-button) and the pop-up-light began to flash. I have examined the lamp, there are no short circuits.

It flashes only when it plays (the disc spins). Whan just on, it has a steady light. There is also a clicking sound when it spins. Only off the engine. Not when I roll it manually.

Luckily I have another SL-1200 MK2 so I have tried to connect that player's three contacts to my player with errors. Pitch control, lamp and (off / on, 33/45 / start / stop) parts are in other words ok.

I have also replaced the IC101 (motor circuit). Yes, I now have one for sale if anyone wants to buy 🙂 I have also changed diode 103 (now 4.7V 500 mW) and resistor 307 (now 10 kohm 0.25 W) which many suggest in various forums.

I have also soldered the contacts in the tone arm.

What do you think is wrong? What should I change / do?

Hi - I have an old amp that used to have an optocoupler in an auto mute circuit to operate during a 2 minute warm up.

This is the component:
https://www.tubesandmore.com/sites/default/files/associated_files/r-vtl5c1_2019.pdf

I have been chasing hum and thought it might be one of these so I removed from the circuit, the hum did not change much ( a little bit) but the sound improved so I kept it out of circuit.

I now wonder if I need to put in some sort of equivalent resistor in the controlling / driven side of what is now a circuit missing a component in a circuit.

To be honest I really have no idea what I am talking about, but I have a problem of instability that is occasional and worrying and it's just a logical question - have I left an unstable circuit with a gap!!

Circuit is here https://www.arcdb.ws/Database/SP8/ARC_SP8_manual.pdf

Chuck Yeager passed.


First american pilot and man to cross the sound barrier and WWII hero who fighted in the french sky and won a lot of battles there.



RIP Chuck Yeager.

Hello,

I have a Tannoy TS2.12 dead. No power, no led light. I took the PSU out and I don't have the standby voltage at all. The PCB is double side, very crowded and difficult to fallow the tracks. Are the schematics of this PSU available somewhere ?
In Primary I have 314 volts on big capacitor and nothing on input of KA78R15 which I think is for standby voltage? What can I check next?


Thank you and Kind Regards.

Hi all,
Please let me know if you have any for sale, ideally in multiples of 10 or more.

Cheers,
cv

Hi,

My receiver has started to power off after 2-3 hours of use. Restarting it will give me progressively less time (10-20 minutes) so I assume it's some sort of heat protection. Removing the cover doesn't reveal any dustbunnys or scorch marks

Any other Yamaha power down threads I've seen so far talk about immediate shutdown or coinciding with a volume increases which doesn't seem to be my situation. The diagnostics menus don't quite match the service manual I found, 20.1 thru 20.4 all say "I PRT". A 457 service manual says that means excessive current so bad power supply?


Any suggestions?

Thanks,

Hi. I want to build a low power germanium stereo amplifier and i got a little stuck...
So the story goes like this: A few years back was repairing a vintage radio and had it hooked up to one of my crappy speakers which had a decent bass for what it was and i was really surprised by the "warmth" and power of that tiny amp. I don't know if it was because all i used at the time were cheap class d board or because of the tapped volume control but I liked the sound and I didn't even know germanium transistor were a thing at the time... Then I started to look for a circuit using these transistors (ac187/188k) and I found an interesting amplifier which is riz transiwatt 8 and it uses these transistors. It doesn't have a tapped volume control but it has a tone control.
Here is a circuit:

https://www.google.com/url?sa=t&sou...Vaw1bdam7IFN2Tf_iu8zoPBSu&cshid=1607085821221

Now here are my questions:

1 what do r13 and r14 do. They seem to be trim pots and i don't know how to adjust them.

2 where am I supposed to find 13M ohms volume pot?

3 is there a substitute for ba103 diode because NOS part costs 20 dollars!!!

4 I see that under each transistor it says another transistor name. I think that is other compatible transistor. Now what do I do. I can get NOS parts or use bc108 ? (I already have NOS output transistors)

And finally is there some suggestions about the pcb layout?

Thanks in advance and sorry for the wall of text. Also if anyone has a better circuit for these transistors feel free to tell me.

Hello all.

Im toying with the idea of building a simple IDHT preamp to clear up some spare parts off my shelves.

Im looking for a nice linear IDHT with a lowish output impedance (less than 5K).

I have thought about a 12B4, 6V6, 6Y6, and 1626 tubes.

The amp the preamp would be driving has an input impedance of 10K.

Any recommendations and thoughts are welcome.

Hi, I know very old and cheap speaker. But, I'm interesting about (yes, cheap and old so I can open and disassemble them).



Tannoy mercury series mx1, mx2 tweeters are the same. I have both. I absorbed weak sound level. It's very low I think. I measured empedance, resistance, crossover; everything is ok. Also, I opened one of them, coil looks good.


Now, I newly learned speakers have ferrofluit and if it loose it's viscosity, it can behave like a glue?! Those are very cheap speakers, is there any ferrofluit in it? I could't find anything in internet. If so I will open and clean it. Or cone may be very old.



How can a speaker lose it's volume? There is no replacement. I want to fix them.

Selling four VBO52-08N07 IXYS bridge rectifiers. These are the stout PWS-D package, and turned out to be just a bit too tight for the chassis I bought them for. They all work fine.

$60 for all four, shipped within US. $50 plus actual shipping cost anywhere else in the world.

Hi
I have this amp and I'm adjusting the bias for the two channels and have a few questions I'm hoping someone can answer for me. I bought the amp with a problematic channel but after looking at it I noticed one of the thermistors, RT3 was not in the heatsink. I put it back together and replaced both trimpots with 4 turn so I wouldn't have the sharp adjustment of the 1 turn. The amp voltages and currents all check out fine and I've spent some time trying to figure out the imbalance in temperature between the two channels and have some hypotheses but need to confirm some things first.

1. Does anyone have the FEB parts list that shows component values?
2. What is the "B" value of the 1K & 3K thermistors? 3800?
3. Should 49C at the rear of the heatsink be the target for this amp as listed in the bias procedure?

What I'm finding is the left channel will settle out at about 40-43C, using an IR thermometer at rear top of heatsink, and the right will settle out at 45-47C when the initial power on current is about 1.4A per channel. When the two channels settle, left~400ma and right~600ma. When I trim in the bias to increase drive on the left channel after it has settled and replace the cover, the left settles back in at 40-43C. I do this twice and let it cool but the problem is when I turn it back on cool the startup current has now doubled and the resulting temp comes right back down. I think I understand why the large increase in current when cool is because the secondary opto compensation kicks in after(above 40C somewhere) but it just seems different than the other channel and I can keep adjusting but not really lock in around 46-49C as I would like. It looks like the diff amp circuit will kick in at about the 48C point, based on the value of RT1 being 375 ohms(48C) if it's a B of 3800. Anyway any help is appreciated.
Thanks,
Kevin

Help!
My CD player is Sony Cpd-X55es, but unfortunately, it catchs a trouble now £¬mainly appearance is that the door open and close automatically, and the trouble is some even if no CDdisk be placed , i want to repair it by myself, so i need the circuit schematics and the service manual for X55ES.
Can anybody give me a help. thanks very much!
My mail is kaisa.xiong@163.com or kaisaxiong@hotmail.com
Thanks for your help.

Hello. When i turn on my amplifier the light keeps flashing red and not turning white as before. I cant locate the problem. Anyone have any suggestion? Would really appriciate it

Hello, I am installing a DACT 100K attenuator and the original potentiometer is a four-pin Alps so I deduce that the fourth pin is for loudness, it could be installed since the DACT has only 3 pins

CSRA6620 looks promising, and unlike Zetex this one is a single-chip solution.
As I see I can buy CSRA6620 for about $5 from Arrow, however, Qualcomm makes from that chip a military-like secret. Any ideas?
Documentation | CSRA6620 | Qualcomm

No interest here, so I am deleting the content.

These were made by Tong-sol , with Bendix specks. I have had both , they sound the same. Tested on a Hickok TV7-U, were 36 is low.
test 62 - 66
62 - 62
340$ and shipping
thanks Rick

I have a DC-offset issue on one channel of an Accuphase E-303, and I can't seem to find the cause, so I could really use some help.

Starting point:
All electrolytics are new.
All other components have been measured and checked (several times).
I found only one defective diode: D3.
It works and plays music just fine, and THD is normal.

BUT: As the amp warms up, the right channel drifts from DC offset at basically zero, to about 650-700mV (a rather suspicious value..).
The left channel only drifts around 30mV, which seems normal/reasonable.

Initially I suspected the input stage, but it measures well balanced, app. 100mV on all Bases of Q2 and Q3.
The problem seems to at the Base of Q13 (the PNP driver), which only has about -0.45V when warm, and it should be close to -1.3V.
The base voltages of both drivers change during warm up - they become increasingly uneven.
Please see attached schematic, where I have also noted some voltages.
The rail voltages are all very close to the schematic values.

The question is why? What can be the cause of this?

I have spent quite a few hours trying to find the fault, and have one by one replaced the following transistors (to try something..):
The Q12/Q13 drivers (with a matched pair).
Q4/Q5 and Q6/Q7.
The STV-3H triple diode, and the VR2 bias trimpot.
All the plain signal diodes.
- All the replaced components test good out of circuit, and the DC offset is still the same (but no worse).

I have also tried removing first one output pair, and then the other, but it didn't make any difference.

Seems like it is a simple issue, but it just eludes me, so would greatly appreciate some help 🙂

SOLD SOLD SOLD FS PAIR JBL CINEMA SPEAKERS MODEL 4670

Gently used pair of 4670's, only ever been in a home theater and never saw commercial use. I ran these bi-amplified with active crossover and i do not have the passive network. You'll need a dsp/active xo like a DBX Driverack/Behringer DCX2496 or similar.

Pair JBL 4508 Bass Bins
Four JBL 2226 15" Woofers OR 2035's your choice
Pair JBL 2080 Horns
Pair JBL 2446 Compression Drivers

I'm selling them to make room for pending and future speaker projects.

My 1st post here: hi all of you!

I want to remove ALPS Blue Velvet from my integrated amplifier and I read somewhere that a resistor of the same value should be replaced with (some say in parallel others in series), but I would like to see a simple schematic, if possible, in order to be sure.

The potentiometer is a motorized ALPS 10KΩ Blue Velvet Stereo (RK27112) just as the picture in attachment.

How to do that?
So many thanks for any appreciated addressing!

Hello everyone,

I am new to this forum and this is my first post. I did use the search function for my topic but had no luck, thus I decided to actively ask you guys for some advice.

As title says, I have a turn on/off pop using an Alpine PDX-M12 for my sub.

Some background: I am currently in the process of upgrading my car stereo. As part of this upgrade I have doubled my sub. So instead of using a single 10" Wavecor sub I am now using 2 of them in a CB, wired in parallel (they are 4 Ohms drivers). My previously used Alpine MRV-T757 (used to run in bridged mode to fire one Wavecor sub) was no longer sufficient to power 2 of them so I was looking for a more powerful amp. I ended up buying a PDX-M12 used.

After installing the M12 and connecting it to the newly built double sub I noticed a slight turn on/off pop which was not present in the previous setup. It is not very loud but audible and I would like to get rid of it, if possible.

I searched the net and came across some threads in other forums where people were reporting same symptons but no real solution or clear root cause. Others were reporting no issues whatsoever with these amps. Seems almost like a hit or miss situation with these amps.

So I am really wondering if something is broken in my amp that can be repaired or if this is maybe a design flaw of the PDX series which surfaces only in very particular setups or equipment combinations.

Thanks a lot for your support!

Holger

Good morning everyone, I have a mmats 1100.1 amplifier on my table, it had damaged mosfets irfb4710 and hip4080 which were replaced, I can no longer find damaged parts, however, I connect positive and ground (without connecting the remote control) and the led " default "stays on, there is no overconsumption, what can be activating this protection without the remote control cable?

Just wanted to spread the word on these in case someone is rehabbing their lineaum two ways.

They have been in storage most of their life and I recently applied new surrounds.


Pair of original 5" woofers radio shack RCA 40-5007 | eBay

Hi guys,

I wonder if it has been done, and what would happen if for a 2 way, the midbass driver is placed into a sphere of known volume and then two PVC pipes are supposedly interconnected into the sphere. One PVC pipe will be closed, the other will have a port to mass load the TL. The main ideas are:

-simple materials to experiment with.
-two pipes, one will serve as the speaker offset to kill the closest harmonic
-street lamp plastic sphere as the primary driver enclosure to reduce back radiation of waves towards the cone. P.S I need to check the BSC frequency with spherical enclosures.

The fullrange speaker can then be mounted inside a second sphere, where a "pseudo Nautulus" can be built, a sphere with a pipe opening and aperiodical stuffing.

What do you think of this idea?

I know a person who once got into a debate with me about choosing the value of amplifier's power supply filter capacitors.
I told him that supply filter cap's value are chosen according to the amount of current it should filter. But, from his point of view, the more the capacity the better the sound quality from every aspect like low, mid and highs are touching the sky.
Anyway, I know that supply filter cap's value make a difference in sound quality. But according to logic/physics, is there a point where this theory becomes useless?

Just to share .

MY HIFI MALAYSIA

Hi all,

I am in the process of building a pair of these: Amiga - undefinition from a PartsExpress kit. These are 8Ohm, 83/84dB according to Carmody himself.

I plan on using a Raspberry PI as a streamer so no need for that feature to be necessarily integrated. I would rather a decent integrated, possibly with sub- and/or pre- outs. Can you guys make any suggestions in the $400-500 or less price range? I'm ok with factory refurbs but would prefer to avoid used market.

Another option is RaspberryPI+DAC hat, into a volume box such as a Schiit Sys, into a power amp. I think. But I don't know how I would ensure these would work together without blowing a speaker or a component...

I have been looking at, in no particular order, Cambridge Audio AXR100 refurb, Allo Volt+D, Emotiva TA-100, IOTAVX SA3 refurb, Yamaha A-S501 refurb...

If there is amore appropriate section for this post, please let me knowing I can repost there. Or feel free to move this post over.

Thank you for your advice.
G

Hi there

I have put a passive output in my SCR 2496, it worked fine, but now it is very muffled nearly muted, I bougt a DIY DAC with the AKM AK4396, put a passive output in it and it also is very muffled nearly muted, i use the french article for my output change, that is a high quality cap, 6,8 µF in series, a 2,2 µF paralel and a 1k resistor direct from the AKM DAC chip, am i doing something wrong?
When i use the active stage all sounds normal.
I am no expert, but play around a lot with electronics....

thanks for information, tojoko.

I think that the ripple from power supply is responsible for at least 30% of "transistor sound". In a way to reduce ripple I have invented this push-pull schematic. I have no intentions to patent it (I already have 3 patents and never made any decent money from them). If it is new I proclaim it public domain (with my name attached to it "Podoliak").
The circuit works as follows:
1). the signal from usual rectifier -WITHOUT SMOOTHING CAPACITOR - is splitted into two regular zener-diode voltage regulator.
2). One regulator has zener-diode lifted from ground to collector - thus the bias resistor and zener diode are interchanged in one regulator. At this point the outputs of both linear regulators can be smoothed by capacitors. The voltage of zener diode(s) should be near 50% .. 55% of max amplitude of signal from rectifier.
Thus, one regulator cuts the upper half of a signal, the other - the lower half.
3). The two signals from both regulators are then summed in bipolar transistor (with high max base-emitter current limit).
4). The output can be smoothed by capacitor in a usual way.
There are two basic schematics in this concept:
= one with lower half - feed into collector of summing bipolar;
= another - lower half - feed into the base of summing bipolar.
This schematic:
a). increses the utilization of signal from rectifier.
b). provides smoothing of two near-equal signal by summing them.
At this point it is just a concept schematic, modelled in MicroCap 11 (9,10) software.

Transient -local pictures show rectifier signal, base of upper transistor, base of lower transistor.
Working title was (like in Hollywood) "push-pull rectifier".

Hello to all

I manage to build a excellent class D amp with 500W RMS power on 4 ohms and 1000W RMS on 2 ohms
I also build a full bridge DC to DC converter to easily driving this bad boy
everything is ok when I connect amplifier input to an external audio device like: my moble, mp3 player,.. etc
but as son as I connect the amp input to the car stereo RCA there is a huge spark and the smps current rises quickly. I guest it's because the ground of smps input and output connect togather as the car stereo and smps are powering from the same power sourse (car battery)
so whats the solution here? how does all commercials amp works then? am I missing some circuit here?

Please help me fix this amp

I am looking for a specific CAS 4040 schematic. My creek has sn:9254. There are a lot of schematics only not for mine.

There is schematic on this forum but i can't reed the numbers. And i can't make contact with the uploader.

I need to know witch transistors are being used or witch replacements can be used. I have the folowing (i think):

Q3: ?
Q4: BFR39
Q5: BD139
Q6: BFR39
Q7: BFR79
Q8: BD909
Q9: BD910

Hello Everyone!


I am kind of green still and am looking for help on building a speaker that will be the same as an Infinity SM-155.

See specifications below:

Power Rating - 10-300 Watts
Frequency Response - 29Hz to 27kHz within +/- 3dB
Crossover Frequency - 500Hz / 5500Hz
Efficiency - 102 dB SPL, 1 Watt / 1 Meter
Impedance- Compatible with 4 to 8 Ohms
Driver - 1 x 15" Woofer, 2 x 4.5" Midrange, 1 x 1" Tweeter
Dimensions - 17.75" Wide, 40.25" High, 12.5" Deep

Tone controls (mid, tweeter), auto-reset circuit breaker protection (mid & tweeter)
Port - Tuned Rear

I need help with the following:

1) driver selection
2) enclosure construction
3) crossover schematic design


It would also be great if someone with these speakers could comment on if there is bracing in the original speakers and what the port dimensions are.


Also is it possible to use a front slot port versus a rear port?


Thank you in advance!

Hello, Have a Bgw Gtb Bought locally Channel A works good but B is out.
Has Yellow Green and Red Lights *Just the Red Light lights as No Green or yellow.
Nice amp would love to take a crack at repairing it Output stage?

There‘s an old technics SP-10 with national-panasonic-mark and original tonearm, all said to be in excellent contition, for sale.

How much is it worth, approximately?

Thank you!

First post on this forum and sorry if there was a sticky about recommended builds somewhere, I did not find it.

I'm looking for ideas/recommendations for a large, max 60L, bookself speaker. The size can be smaller of course, but since a big percentage of my listening is movies and series I prefer the dynamics and overall benefits of bigger speakers. I also like directive speakers (horns and such), but I'm always up for a change if there is some compelling build. Since the speaker would be a bookself the height would be limited to 60cm.

At the moment I'm using Finnish speaker designer Samu Saurama's coaxial desing. It uses Eminence CX12 woofer and Selenium D220Ti compression driver. I also have two subwoofers to deal with under 80hz frequencies. I would like to keep my crossover at 80hz or below.

Now I'm looking for a step, or two, higher in overall sound quality. Samu's newest design using B&C 15CXN76 piqued my interest first, but I felt curious about other options outside of Finland.

After the initial interest in better coaxial design I started to look at 2-way designs using horn and 10-12" woofers. These seemed interesting but as I read more about the designs it seems that they is fundamentally "flawed" because the matching of horn and the woofer would require rather large compromises in almost all situations. I started to think about 3-way builds, but I just thought that I might be better off asking recommendations at this point.

I have no speaker design skills other than that I have designed my own subwoofers and build my current speakers following instructions. I'm not necessarily looking for a ready package (such as DIYSG-builds), parts list and crossover schematic will do.

So, do you guys have go-to build ideas? I list a few builds I have found interesting below.
- Samu Saurama's other builds (coaxial and 2-way designs in general)
- Econowave (mainly PA310-8 and D220Ti version)
- TPL-150H-based builds (this would probably be a challenge to make work with 2-way passive design?)
- Some 3-way build (I think the speaker height would become limiting considering this option)

And just to be clear, my requirements and limits for the design:
- Cabinet size 60L or under, height 60cm or under, bookself speaker.
- Used for movies, series and music. Personally I prefer more directive designs.
- Passive crossover design preferred.
- Bass extension to atleast 70-80hz
- No specific budget yet, just looking for ideas in general.

Hi everyone I am new on this forum. I am requiring some guidance in the trouble shooting of a fault
I am experiencing on an old Spirit Folio Notepad mixer by Soundcraft - pc board revision 6. The issue is L and R peak led’s remain constantly on.
What could be causing this and a remedy ?

Been absent for quite a few years, cleaning up the basement i stumbled upon my ECM 8000 + Preamp that i originally bought to use with PC based softwares for measurement and tuning of loudspeakers an complete systems.
Should i sell those or keep it ??

What is the new good stuff for DIY measurement/tuning for systems, setups and rooms ?

I plan on working on living room and HT systems in the next few years ( finally ) so don't want to sell things i'll need when i get there.

But same time, would like to learn about the new methods
you guys might have developed or found .

Thanks for your time 🙂

Hi cheshtap,
can u tell me what are the diodes i pointed in the pcb image.
thank u.

Hi,

I built a set of the "Fast Fun Inexpensive OB Project" speakers in late 2017/early 2018. The crossovers are based on what was on the thread at that time.

Fast, fun, Inexpensive OB project

I ran these for a short period and they sound good. I then ran into a a very nice deal on a pair Linkwitz Orions on Craigs and went that way.

These need to get out of the way. I disassembled them and got rid of the baffles.

I am offering the whole package at a great deal and hope someone has fun with them.

2 Peerless 830669 12" woofers (seem to be out of stock everywhere).
2 TC9FD-18-08 midrange
all of the electronics in prototype assembled form - no soldering, so easy to adjust

Electronic components are mid-range like Audyn capacitors etc.

I have the original boxes for the Peerless woofers (see pic).

All for $125 + actual shipping. Free pickup in Denver area. Paypal fine.







I seem to be having a problam with the pic insert. Use these URLs to see pics


Imgur: The magic of the Internet
Imgur: The magic of the Internet
Imgur: The magic of the Internet
Imgur: The magic of the Internet
https://imgur.com/8elVgc0
https://imgur.com/eeJkb2U

Hello,

I am a little confused by the 50ASX2BTL input diagram, I thought this amplifier board had a balanced input.

My plan was to go from the TRS out on my Focusrite Scarlett Solo gen. 3 to the 50ASX2BTL, but the diagram makes it look like you just tie both inputs on the 50ASX2BTL to a single output on "preamp" like you would with an RCA.

Am I reading this wrong?

Any help would be appreciated!

Thank you,

David.

The mail arrived today,-5x Coral Flat 8 II's and a Quad Vena II amp. Two of the Corals are modded with a phase plug, three are unmodified. I plan to put two of them in an Open Baffle system, (not sure what to do with the remaining) but while waiting to get the baffles made I just couldn't resist having a listen.
I've read a lot about full range speakers, rumours of shoutiness and unwanted resonances made me unsure about spending money on full range speakers at all. There's two things I can't stand: -Shoutiness and shrillness!

No baffles yet, so I placed two of the Corals at an angle towards the wall and played some music: Ein Straussfest from the Telarc record company,-no dynamic limit with gunshots and the whole works. Skinny Tuba (blues/jazz), Postmodern Jukebox (jazz) and the tune "After you get what you want" from the TV-series Boardwalk Empire.

#1: Ein Straussfest sounded,-well, dynamic (who would have thunk!) and unrestrained. The gunshots didn't seem to bother the speakers one bit.

#2: Skinny Tuba has a female singer. Her voice sounded very pleasant, no problems there.

#3: The song from Boardwalk Empire is performed by a female singer with a voice that could rip the skin of your back straight off and make your ears bleed, but even her voice sounded OK. Much better than I feared it would sound.

To sum it up,-the Coral speakers have made me look forward to building baffles for them, they do sound pleasant and even if they probably don't go up to 20 kHz they do not seem to lack treble.

In case of any lack of bass I have two 15 inch Eminence Alphas lurking in the corners.

I have an RCA 632-11. All fm stations were working before and after the recap. I believe they quit after mounting the tuner back into the console. Now with AM the stations are controlled by a tuning capacitor, but with FM it uses a multiplexer right? Would that be the 6ba6 tube?

Is there anything else I could double check? I start to lose stations after 95, and there is nothing. No static when sweeping or anything!

Dutch and Dutch achieve a 20dB drop from front to side in their 8Cs. I built a low-mid cardioid but can only get a 8dB drop over the 200Hz to 1,200Hz spectrum. It is passive cardioid without active bandwidth cancelling.

What would you consider a successful drop in dB at 90 degrees off-axis over the 200-1,200 bandwidth using strictly passive methods?

I don't know if I can keep gaining more with passive or if I should just be happy and start working on active cancelling.

My first Amp Camp amps are to be built soon and a B1 buffer has just been completed. So it’s time to decide what speakers to build.

I suspect that there may never be consensus on the ideal DIY speaker to bring out the best in the ACA’s, but I’m trying to draw up a short list for the speaker build. The listening area is 18 feet long x 13 feet wide. It’s just for normal home use - no parties.

So far, someone has suggested in another thread that 8” or 10” classic Audio Nirvana full range drivers would work well (no mention of the enclosure, though). I have also been eyeing single 5”Dayton Audio PA130-8 drivers in 0.53x Karlsonators.

I’m considering the Karlsonators because it suits my budget, but I can’t help but wonder if there are other suitable options.

Christo

Hello all, love my music, and my workshop amp just died. Its a Kriesler ka4000, full transistor amp. I have had a play with it and found the signals get to what i think is a long tail pair, and i used the finger test to get hum to test the rest of the amp, and both channels appear ok after the input circuitry. Because both sides dont work i thought the PS might have a bias voltage to those particular sections but it all seems ok.


I was wondering would anybody have a circuit of this particular amp....... I have scourged the net and it seems kriesler is only known for its old valve radiograms and mantle radios. It would be greatly appreciated if someone could pluck a cct from i dont care where 🙂
--------------------------------------------------------------


Thanks everybody for looking, waited a couple of days in hope, i'll start tracing it out...........

Hi all, i am looking for the article from ETI-june1982 the mosfet PA called project 477 .Please if anyone has it ,or a link to it, help me!
Thanks!!

Hello to the Forum


Few months ago I got a Fostex D-15 reported as dead, coming from a building clear out. Only recently I had some spare time to look into it.


Once opened It showed some signs of hard impact: the bottom of the case was deformed near the feet and the control panel PCB was cracked on one corner near a fixing screw. Even the VFD pins was slightly deformed downward. The cassette door had both the hinges broken but still in place. The device had clearly fallen down on its feet during moving operations...bad start...


I fixed the control panel PCB (no lines was actually interrupted), unsoldered the VFD, straighten up its pins and put back in place.
I then removed all the PCBs and did a very careful inspection of all the components and lines, looking for craks, cold soldering or any other visible damages caused by the mishandling. Everything looked fine.
While everything was disconnected from the power board, I turned the power on and measured all the regulated lines. All the voltages are as espected and stable.
Put back everything, reconnected all the cables and powered on again...no signs of life.
The only things that seem to work are:
- VFD cathode lines: they heat on normally
- cassette vane light
- a red LED on the video sync board. It flashes few times after poweron and then shuts down permanently.


At this point I am stuck.
I don't have any experience with this these decks and I don't even know exactly where to start looking from.


Hints are really welcome.


Thanks for reading


Raffaello

Hi Guys,


Is anybody able to suggest where I might find good quality octal sockets?


Nothing is available locally.


It doesn't appear as though they are available from any of the standard reputable suppliers eg: Mouser, Farnell, Digikey etc.


Has anybody had any good experience with the stuff available on ebay?

Are there any command line DSD bitstream generators out there (GitHub etc)?

* Create a mono DSD512 bitstream given a requested frequency.
* Enhance later to convert PCM to DSD.

If not I'm tempted to write a simple one.

These caps are normally 70$ each . Copper and oil cap .@ 1mf .
59$ for both and shipping.
thanks Rick

Hi,

I'm looking at placing an order for the Ian Canada Fifo Q3, Transporter, and super capacitor Pi filter. At the same time, I am looking to order upgraded clocks.
I was hopeful someone may be able to clarify what clock speeds are required for the upgrade. I.e. do I order the same clock speeds, do I need to mix and match etc.

Example Clocks:
CRYSTEK CCHD-957 Ultra Low Phase Noise Clock 49.152MHz 3.3V 25ppm - Audiophonics
CRYSTEK CCHD-957 Ultra Low Phase Noise Clock 45.1584MHz 3.3V 25ppm - Audiophonics

Fifo Q3:
IAN CANADA FIFOPI Q3 ULTIMATE FIFO Reclocker Module PCM 32bit 768kHz DSD1024 DoP - Audiophonics

The manual doesn't seems to cover this, unless I missed it.

@iancanada, it would be amazing if some kits existed which would allow novice users to buy the correct boards with a pre punched case. I think this would go a big way to helping users like me get off the fence and purchase.

some drivers have quite deep cone profiles and other have a lot shallower ones, what sonic differencies will this make? i have the impression that shallower cones sounds more open or big then deep cones, is there really any difference in "wave front"?

Does anyone have one of these laying around? If so, what's your price?

Thanks
Tim

Just wondering if somebody could relate if they had any success with some of the Chinese branded full range drivers available on eBay and Aliexpress? It's not an easy topic to search for. Looking for info on what drivers worked out and the user managed to get TS parameters from vendor or other source. TIA.

I've been asked to assist with a car audio build that's using a Sundown NightShade NS-15 V4 D2 to provide bass duties. Sundown recommends a 4.25 cu.ft. tuned to 32 Hz and I've put together a bog-standard vented box design that meets those specs. Hornresp suggests that the build will produce a fairly big peak at around 30 Hz and starts rolling off about 60 Hz.

For a lark though, I also put together a POC7 TH design for the driver that's only slightly larger (2 inches deeper) and the results look interesting. The rolloff is reduced (as is the peak at 30 Hz) and, apart from a peak around 100 hz that can be reduced with EQ, it looks like it has a fairly decent usable passband.

I don't know how this driver will actually perform in a TH though. Is anyone here familiar with it?

I do believe this is probably a very simple question to answer, but for the life of me I just can't figure it out.

What is the "Vin" value in SE Amp Cad?

The help pop-up in the application explains exactly what it is, however I have no clue what it means or (more importantly) how I am supposed to figure out what value to plug in here for accurately running simulations.

Hi,
on all Thorens TP 14 tonearms I have seen, the tracking force balancing weight is sagging. This is because the rubber decoupling part has degraded.
To repair this, I use two PVC grommets from Farnell, part number 152-332.
Cut off one side of each grommet, leaving the middle part intact.
With a sharp cutter knife, reduce the diameter of the crommet that goes in the arm tube, to make it fit.
That's all.
I am open to all comments.
Best regards, 968driver.

I've seen some pictures online of the grill removed, but would like a second opinion as to whether this is a undo-able operation and if there's any risk of damage.

This is my latest project for a while and the next one that I will put into practice, given that I already have everything I need to build it (I will use a pair of OT 2300 instead of 2500, but there won't be much difference). 3 watts are obtained and a distortion around 3% ... as always all the corrections, and suggestions will be welcome before the work begins.

Hi ! sorry for the very generic question in the title. I wonder if The Lounge or Everything Else coud be a better place to ask.

When you design a circuit do you simulate it first or not ?

and if so, is there a fair correlation between simulation performance and then actual performance measured on a prototype ?
Thank you all and have a nice day, gino

At the urging of a couple of other DIY members that claimed the 12B4 would stomp the Rosenblit Grounded Grid I decided to persur building one.... I left a trail of metal shavings fomr Cody to Rock Springs Wyoming as I partially assembled this on my last service trip. This IS alot more fon that watching cable TV on the motel rooms!

My grounded grid follows this basic diagram. I can't remember where I found this one but it was within a thread on this site that I found the link to it. Mine is pretty much a stock 12B4 as was my Grounded Grid. The only change I made to the grid when I built it was to use a different feedback resistor(less feedback) and a variable regulator IC in place of the fixed 12 volt IC. This allowed me to use the designed 12.6 volts on the filaments of the 12AU7's instead of Bruces 12 volts.

How do they compare.....? Listening tests were done with my Dynaudios driven by my DIY overbiased/overbuilt Aleph 2s. Source was from my Pioneer DV-45 CD player, a long time favorite of mine and one which has the proper DACs for the proper type of disks! All three types of CD's were used in listening tests.

The Grounded Grid is very detailed and open and extremely neutral and very dynamic. Overall its a very pleasing line stage to listen to once a good tube type is found. Yes, its somewhat tube fussy as I finally ended up settling on NOS Tung- Sols in mine. This seemed to be the best choice forthis line stage. JAN tubes while less microphonic were much more strident sounding on the high end. Did I say microphonic....... Yes. The grid suffers from this plague to some extent although I never found it to be a real problem. My stereo rack pretty is well isolated and on spikes.

Overall the grid has been very good and I've lived with it now for well over a year.

Then commeth the 12B4!

What can I say when something is so dramatically better. To try to sum it up I'll say that this simple circuit is the real meaning of more for less. By that I mean more music for less parts used. Somewhat the same basis for the Aleph series of power amps too.

This line stage has detail and top end that have to be heard to be believed and seemingly unlimited dynamic range. Its also drop dead neutral. As a comparison to the GG the 12B4 has alot more leading edge comming through than the Grid does and thats the single most obvious difference between the two. The bottom end and midrange performance are very simmilar to the grid but again with the 12B4 revealing even more detail and nuances deep in the music. This is very evedent on plucked bass and vibes and is pretty amazing. Background noises in recordings start to get annoying with the 12B4! Overall this is a much more musical line stage than the grid. Its hard to believe that high end tube equipment manufactirers have not hit on this tube, their engineers must be .

Are there any drawbacks? YES! This line stage has just about zero Power Supply Rejection and requires the very cleanest power you can give to it. Does it need to have a CSS or LED's to sound good. NO! This stock circuit is simply amazing running off my regulated bench supplys. The CCS mod might raise the PSR a good bit but good regulated supplies as Dr. Gizmo used to do and as I am doing also works very well. Its either going to take alot of iron or some well designed regulated power supply to get this unit hum free.

So have I retired my GG? No, it'll serve in another system in another room. Its also a very good piece but the 12B4 does indeed blow right past it.

Simply put the Grounded Grid runs at Warp 5 and the 12B4 runs at warp 9.

Build your self one!

Mark

After Dynaudio decided not to talk to DIY-ers anymore it`s not easy to find any good sounding 2" or 3" domes for a four-way system.
Does anyone know where to find some? Monacor are still selling one 2"`, that`s all I know😕

Sold!!!
new in box.
100.00 for pair plus shipping.

Hey guys I'm having a very frustrating time putting together a set of speakers I'm working on. It's a bookshelf, Dayton BR1 bookshelf enclosures with Peerless drivers.

Tymphany 830874 6-1/2" PPB Cone HDS Woofer
Tymphany XT25TG30-04 1" Dual Ring Radiator Tweeter.

I'm running active, crossing over everywhere from 1500hz up to 5000, right now I have the mids just running full range.

Speakers are being powered by a zoudio 4 channel amp with dsp. 50wrms x4 @4oms.

I think one hurdle I'm facing is that my woofers are 8ohms, tweeters are 4ohms.

but whatever I do The sound is very muddy and removed. Question: Should my midwoofers sound GOOD just hooked up and running full range??? they sound terrible... What could I be doing wrong??

I wonder if my amp is just junk ??? not enough power?

In another post I asked if anyone had built the M J King Satori MTM.
But it seems no one has done so I have some other questions.
1. There are no dimensions for the driver centres but am I right in assuming that with an MTM it is best to get the centre's as close as possible together.
2. I know Martin is well known and well regarded but what do you experts think of the crossover that has been designed for this MTM
Thank you

I have recently acquired a pair of Eltax floor-standing 10i speakers. They are surplus to my requirements and pretty damn awful.

They are literally a waste of space. The twin 5" bass drivers produce little or no bass. However, the design of the cabinet provides room for me to install a 6.5" down-firing sub. (The speakers are on spikes anyway).

The logical solution would be to seal the sub in the lower half of the box. However, this would require carpentry skills beyond my pay grade.

What are the effects of the subwoofer, the two bass drivers, and the port all sharing the same internal airspace.

Hopefully you can see from the pic what I'm trying to do.

Hi, I am looking for a service manual (schematics) for the Wharfedale powercube SPC-10 10" subwoofer. Could anyone please advise where can I find it? Thanks in advance!

I have built a number of Naim NAP250 clones with 20Ω Draloric AC wirewound resistors in their Zobel networks (as in the originals, I believe).

But I've recently understood that their inductance can swamp their resistance at high frequencies, and if said high frequency is less than the fT of the output stage then you've essentially got no Zobel network for half of each cycle.

So I thought I'd better find out what the inductance of my wirewounds is. Of course the datasheet doesn't spec it. 🙁

Being that I'm in no great hurry I fired off an email to Draloric/Vishay. This was around 11pm on a Sunday.

I get a reply at 5am Monday morning: 0.26µH. Now that's customer service!

(And for those of you curious my resistors turn inductive at a bit over 12MHz. Probably another reason NAP250's had a tendency to fail with no load hooked up.)

Hi, this is my first post so welcome. Is there any possibility to measure output voltage of cartridge? I've got Ortofon Rondo Blue. On the paper there is 0.5mV but I think, there is much higher. How to chceck it? I've test record with 1kHz signal. The multimeter (mV AC) connected to output said about 0.91-0.96mV. Is it true?
Regards

Wanted to build a 2-way kit that exhibits linear acoustical phase property. I found the "Tributes" kit by Jeff Bagby.

Are there other 2-way kits out there with linear acoustical phase, maybe nicer drivers?

I've seen it mentioned it is a generally a bad idea to use them, it has to do with capacitance I presume.

Is it a good idea to use them as input devices? Say a solid state source driving an input tube?

Or use it on the output of a solid state amplifier (plenty of current, but not enough voltage gain) to drive a power tube?