Quantcast
Channel: diyAudio
Viewing all 93581 articles
Browse latest View live
↧

FS: Threshold FET One preamp

August 24, 2019, 6:08 pm
$
0
0
No introduction needed for this legendary preamp, designed by Nelson Pass. This was their TOTL preamp in 1982 @ $2,200.

I picked it up back in March to pair with my Pass Labs X150. Great combo, but I bought a new tube preamp. Passing this along for what I paid, which was a steal IMO.

All electrolytics have been replaced with Black Gate and Illinois Capacitors. The power supply diodes/rectifier have been upgraded to Fairchild Stealth diodes. All the work was done prior to me buying it, except the 3 new Illinois Caps in the power supply, which was done at then end of July. I used Cardas silver bearing solder. No odd noises or issues, it's a very quiet preamp.

*Cardas rca covers NOT included.

Asking $850 shipped, PayPal fees included, ConUS.
↧
Search

alpine pdx 1.1000

August 24, 2019, 7:05 pm
$
0
0
hello, I get this alpine pdx 1.1000, turn on, the source delivers +54 -59 volts, everything looks good, I only found sd902 diode in short, replace the diode and everything remains the same and that is when I realize that I have no output voltage For pre amplification in both transformers (leg 16) I must have 20 volts and it does not reach 2 volts, is there any component that activates the voltage at these outputs of the transformer? the transistors regulators of the main card as the regulators of the pre card mark ok.


I already downloaded repair manuel but it doesn't give me a clue of the possible solution, thanks in advance
↧
↧

WTB Shinkoh 2watt 1K Tantalum Resistors

August 24, 2019, 7:08 pm
$
0
0
Hi Guys,

If you've got some to spare, kindly pm me pls.

Thank you
↧

mpd service or Who wants to live forever...

August 24, 2019, 8:06 pm
$
0
0
How can I stop/disable mpd service at startup?

I tried to stop/disable mpd as a system service:
Code:
sudo service mpd stop
sudo update-rc.d mpd disable
sudo systemctl disable mpd.socket
sudo systemctl disable mpd.service
It didn't help. Also I tried this proposal:
systemd - Prevent mpd finally from auto-starting - Ask Ubuntu
It didn't work either. Whenever I start RPi I always see mpd process running:
Code:
pi@raspberrypi:~ $ ps -elf | grep mpd
0 S pi        631  556  0  80  0 - 49135 do_epo 03:56 ?        00:00:01 /usr/bin/mpd --no-daemon
What else should be changed to avoid mpd running as a service at startup?
Thanks!
↧

Help Needed with TSE-II Configuration Decisions for a First Time Tube Builder

August 24, 2019, 8:21 pm
$
0
0
I am building my first tube amp and would really appreciate help from experienced builders to select the right configuration and parts for a good outcome on my TSE-II build.

Background Information

Before I jump into the build decisions, I wanted to provide some details on my system, musical tastes, and goals for the amp.

My primary speakers are Wooden Designs Vulcans (FE206EN Back Horn ~ 96 db efficency) they make good bass and I would like to run them full range with this amp. In another thread there was a comment that the impedance of these speakers might be a problem for a tube amp. I have included a simulated impedance chart below taken from this thread. Does the impedance look ok?

I mostly listen to classical/acoustic music and classic rock, at moderate volumes (usually at night when the kids are in bed).

I have two goals for this amp 1) to get an accurate feeling for what a very good tube amp sounds like 2) make the amp versatile enough to run both high efficency drivers and some thing more conventional along the lines of Lynn Olsen's Ariel speakers.

If I am really missing the boat on my build decisions, please keep in mind that I have never heard any tube amplifier before, and never even held a vacuum tube until my 5842's arrived a couple days ago.

Build Decisions:

Tubes: 300B's - Available New, Most Power (helps with the versatility goal), Good Reputation, thinking Genalex Gold Lion from Viva Tubes (~$210 per pair)

Output Transformer - 5000 ohm primary, Multitap 8 ohm and 4ohm. Based on the Western Electric table of "Recommended Operating Conditions" for the 300B i am thinking that a 5000 ohm primary operating around 400V and 60 mA would be a good balance of power vs. distortion. Thinking the One Electron UBT-2 would be a good choice, but I am definitely open to something else.

Built in Volume Control - I would like to include a built in volume control and source selector, but I don't know the gain of this amp. Any idea on the gain of a 300B TSE-II?

Thanks!

Attached Images
File Type: png Vulcan Curves.png (35.5 KB)
↧
↧

Matching tubes, what parameter to use?

August 24, 2019, 9:11 pm
$
0
0
It would seem that matching on their gain would be best?

Is it?

Or is there a better parameterto match them on?

Thank you
↧

Can Califone PA OPT's be used to build a tube amp

August 24, 2019, 9:21 pm
$
0
0
I have an old Califone PA Model 35 with a nice looking OPT and wanted to confirm if it could be used to build a tube amp? Any input would be greatly appreciated.

Attached Images
File Type: jpg Caliphone Model 35.jpg (154.9 KB)
File Type: jpg Cali 2.jpg (52.1 KB)
↧

distortion in speakers discussion Klipsch vs Hartley

August 25, 2019, 10:31 am
$
0
0
The attached article is an exchange in "letters to the editor" in Radio-Electronics, 1957. I suppose it could be considered an ancient form of flame war since it gets a little snotty in places, though subtle.

It seems the two gentlemen got sideways with each other over their repective products and philosophies. At that time, not everyone was willing to admit that the cone movement caused by a low frequency signal could frequency modulate a high frequency signal being reproduced by the same cone, and to what degree cone movement should be limited to minimize that in a full range speaker. Some 'dismissals' of those facts were probably related to the product being marketed at the time, especially in small diameter full range speakers with large excursions.

Part of the contention revolves around data in the book "ACOUSTIC DESIGN CHARTS" by Frank Massa. Chart 61 is especially interesting.

The book cited is too large to attach but can be downloaded here:
Acoustic Design Charts : Frank Massa : Free Download, Borrow, and Streaming : Internet Archive

Attached Files
File Type: pdf speakers klipsch-hartley.pdf (652.4 KB)
↧
Search

Kenwood 7020

August 25, 2019, 10:57 am
$
0
0
Evening all

I acquired one of these monster 90's amps recently for restoration. Top of the Kenwood line in 1990/91. Dual transformers, massive 15,000uF Elna capacitors, all good stuff. This one was caked in dust and while it sort of functioned it sounded like a worn out amp. I've restored it by cleaning it thoroughly and re-capping it throughout (many of them were failing badly), but i'm now having trouble resuscitating it!

Tracing the audio signal through the circuit(s) (with my equally ancient Kenwood oscilloscope!) it gets as far as the front panel PCB, enters a pair of op amps connected with the loudness circuit but doesn't emerge. Bypassing this circuit with 'source direct' gets it to the little volume control daughter board, but again, it goes into the associated volume control op amps but doesn't come out. All the circuits/op amps seem to be correctly powered, the main power amp DC offset and bias are all ok, and it's possible to get some very nice sound out of it (albeit very quiet) by bypassing the volume control with the audio signal that's made it this far - so the power amp seems ok.

Weirdly, when you really crank up the input signal the sound 'breaks through' (even with the volume right down), albeit very rough?!

I'm at a slight loss so I thought i'd canvass some opinions :-)

Hope you can help!
↧
↧

Bluetooth speaker retrofit

August 25, 2019, 11:30 am
$
0
0
Hi All, I hope I'm in the right forum. I got a Cambridge Soundworks Center channel speaker for free, and I thought it would be fun to make it a built-in stand-alone bluetooth speaker. Most of the chip amps I've seen have two channels, a left and a right speaker. This center channel has two midrange, apparently wired in series, and one tweeter and they connect to a crossover (I guess?). How do I wire the speakers to the 2-channel amp with one tweeter? Do I use the crossover somehow, or eliminate it? Any other advice you can give me? Thanks all!

Attached Images
File Type: jpg 20190825_141417.jpg (182.1 KB)
File Type: jpg 20190825_141400.jpg (373.5 KB)
File Type: jpg 20190825_141343.jpg (805.0 KB)
File Type: jpg 20190825_141532.jpg (753.0 KB)
↧

Just wanted to say hi.

August 25, 2019, 11:31 am
$
0
0
I've been a DIY guy for the last 30 years.

Had a acct here for the last 5 years but was busy posting on another big forum.

I figured I should finally say hi. HI!

I have a DIY home theater. 3 way active mains with 2226's and horns, custom sub, DIY screen.

I'm about to design and build a new theater. My old one is torn apart and on its way out. I plan on doing some over the top stuff with it. 160 12's in a baffle wall, 50-100kw of power, quad 15 LCR.

I found an auction and bought most of the gear that I'm planning on using for the upgrade.

I have a lot of good stuff that came with it that I won't be using tho. Literally tons. I'm spending the next few weeks testing everything.

I wanted to reach out to this forum and let people here know.

It's on the scale of Erich's JBL buy that was the beginnings of diysoundgroup.


Thank you
↧

Sanity check on psu for a direct coupled 45 headphone amplifier.

August 25, 2019, 12:40 pm
$
0
0
Hello all.

This is my first time using voltage regulator tubes as well as my first time making a shunt regulated PSU, so I would appreciate some feedback to make sure I am doing things correctly.

I am aiming for an output voltage of 408v with a load of about 85ma. The idea is to bias each 45 tube at ~35ma a piece and then bias the regulator tubes at ~15ma.

I know tube regulators need slightly higher voltages for ignition and regulation. I am not sure I have enough extra voltage at 450v. One thing I can say is that the power transformer we are using is rated for 115v on the primary. So even if the line voltage does drop a bit, we should be ok. But thankfully the line voltage is actually pretty high at 123v, so we should be good.

At least I hope so : P

I also hope using a simple cascaded IXCP10M90S would be sufficient for a CCS. If I can do better, please let me know.

Thanks for any advice in advance.

PLEASE IGNORE THE 100UF INPUT CAPACITOR. I was in a rush and forgot about the maximum input capacitance of 50 uf.

↧

Ribbon/Flat Cable

August 25, 2019, 1:20 pm
$
0
0
I am still trying to make my X-Ray behave with minimal tooling. However I have reason to believe that the problem could well be the ribbon cable that is connected to the KSS-240a. Although I think I have found someone selling them, it is on the other side of the world plus it is not cheap.
Is there an obvious place I should be looking for such parts? What I need this time is a flat cable, 12 core, 100mm long & 13mm wide. Is this a difficult ask? Is there a supplier in the UK that specializes in such things?
It would be good to know for future reference as it seems a lot of these kind of cables are expected to flex many thousands of times during their service.
I am surprised at how much difficulty I am having finding some of the parts, having said that, this is not my area at all, so I may very well be being naive.
↧
↧

Heatsink Calculation for LM 317/337

August 25, 2019, 1:22 pm
$
0
0
I just need to select a Heat sink for Lm317/337, i have Texas Instrument T220 devices and i am a little confuse about; the Junction-to-ambient thermal resistance is 23.3 °C/W, the Junction-to-case (top) thermal resistance 16.2°C/W.With the same T220 (Case 221AB) device with On conductor the Junction-to-ambient thermal resistance is 65 °C/W and the Junction-to-case (top) thermal resistance 5°C/W.

What values should i use for heatsink calculation ??

Attached Images
File Type: png LM317 Texas Instruments.png (116.0 KB)
File Type: png lm317 On Semiconductor.png (126.6 KB)
↧

Any recommendation towards Class D?

August 25, 2019, 1:39 pm
$
0
0
Not sure if this is the right section to ask, but I am intending to get a class D amplifier.

I have zero technical knowledge. So first option would be to buy a prebuilt one.
Second option would be to get a schematic plan and the parts needed and ask a friend that knows how to at least read those schematic plans and that hopefully can help me put the parts together.

Requirements for the amplifier itself would be the following:
-USB/optical input (preferably the former)
-around 100w @4 ohm stereo
-cost should be around or below 200

So are there any reasonable priced ones around with decent build quality? Chinese ones or anything really works for me.
If not how feasible is it to build one myself within those requirements?
↧
Search

Cancelling noise from other room

August 25, 2019, 1:42 pm
$
0
0
New to the forums and don't know much about sound design. I wasn't sure which group to post this in...

Our living room surround sound system has three speakers plus subwoofer right by the tv, which are all about 12' away from and in line with the doorway into the kitchen. I'm not sure if it's the acoustics of the living room or what, but any time the volume is at the right level for the people watching TV, the sound can be heard in the kitchen and it seems even louder than in the living room.

I was reading today that if the wires are reversed on a speaker it can actually cause inverse sound waves (I suppose this means they would cancel out). Alternatively, I've seen speakers which are designed to be noise-cancelling. Would it be possible to put a speaker in the kitchen that cancels out the sound coming from the living room speakers? Thanks for your help!
↧

Alpine 5952 Pinout

August 25, 2019, 1:53 pm
$
0
0
Pin configuration for Alpine 5952-5959 changers posted for a member needing info.

Some of these models bundle the signals in the DIN cable, some use outboard RCA's. Otherwise they are compatible.

If anyone has information on the large 12 disc, first-generation Alpine players that BMW used, please chime in.

Attached Images
File Type: jpg Alpine CD DIN.jpg (722.6 KB)
↧
↧

Super Pensil Curiosity

August 25, 2019, 4:34 pm
$
0
0
I'm a Pensil devotee and started thinking (and that's usually a problem :D). I see that there is a Super Pensil for the 12p, why couldn't there be a "Super" type of alignment/design for the other Mark Audio Pensils? I'm assuming the Super for the 12p is to extend the bass response? I'm listening to my 10p Pensils, the mancave is rocking...:)
↧

Anyone try the SPDIF connection in TV sets ?

August 25, 2019, 4:41 pm
$
0
0
Anyone try the SPDIF connection in TV sets ? Are they noisy or just as good as the SPDIF from CD players ? Maybe add a nice OCXO reclocker though.

Thanks.
↧

Are horns easier to use active x-overs?

August 25, 2019, 4:51 pm
$
0
0
Hi Everyone,

I just thought about something and I'm wondering now if I'm missing some inherent horn / PA speaker goodness. I have been over at Audiogon discussing the pro's and cons of active vs. passive. I'm not religious, but I found myself with a bias which may be due to building multi-way home speakers. That bias is that designing an active crossover well is still difficult.

One thing I always have to incorporate into a crossover is some EQ. Usually to extend the bass ( baffle step ) or to extend the treble and get flat past 20 kHz, not to mention get great phase matching. All of this, of course, can be handled by an inexpensive unite like a miniDSP. Bear with me a little longer please.

Then I was reminded of my brief exposure to theater speakers and professional line- level crossovers, and I realized how utterly simple they were. You had frequency and level, and that was it. I mean, the level of care, and fussing I put into a crossover design just kind of vanished! It was never there.

I'm asking those of you with experience in the pro world, is there something about horn loaded pro speakers which made them much more active x-over friendly??

Thanks,

Erik
↧
Viewing all 93581 articles
Browse latest View live
Search