diyAudio - Blog Entries
Go Back   Home > Forums > Blogs
Home Forums Rules Articles diyAudio Store Gallery Wiki Blogs Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Old

Hiphonics Zxi 1008 amp repairs almost completed

Posted 9th February 2016 at 11:38 AM by tscr2015

The customers original problem with this amp was that it had no sound on one of the two channels, after replacing various components in the amp section and the power supply section it turns out that all it was, was a bad crossover selector switch. The contacts had broken on the inside of the switch. Sourcing this switch is a problem because most companies carry it but you have to buy like 100 or more at $.40/ea. Did find that I can get one from Mouser electronics next month. So in the mean time for testing purposes I hard wired the contacts in the switch together with solder until I can get a new switch.

Stay tuned....
diyAudio Member
Posted in Uncategorized
Views 30 Comments 0 tscr2015 is offline
Old

Headphone amplifier ground. Where to make the chassis connection?

Posted 2nd February 2016 at 08:11 AM by rjm
Updated 9th February 2016 at 08:36 AM by rjm

The discussion thread at the headphone forum is here, but I wanted to throw out the problem to the general blog-reading community here at diyaudio to see if anyone can nail this.

The earthed chassis (light blue) must connect to the circuit common i.e. "ground" (pale green). I do not know where the best place on the circuit ground is to tie that connection.

Suggestions please!

(COM and GND are completely equivalent pads on the circuit board, while IN- and OUT- also pads on the board but physically further away on the ground plane.)

****

Answer: as long as it connects at one point only, or the same point of both channels, it doesn't seem to matter at all. I have it connected at the ground tab of the headphone jack and that seems to be as good as anywhere.

****

The noise is a 60 Hz waveform, a positive spike and a negative spike once a cycle. It appears to originate from the current flowing...
Attached Thumbnails
Click image for larger version

Name:	Sapphire ground.png
Views:	35
Size:	32.5 KB
ID:	1775   Click image for larger version

Name:	DSC_5322b sm.jpg
Views:	30
Size:	846.7 KB
ID:	1777   Click image for larger version

Name:	DSC_5407 sm.jpg
Views:	46
Size:	748.4 KB
ID:	1780   Click image for larger version

Name:	Z-reg sim.png
Views:	24
Size:	273.4 KB
ID:	1782   Click image for larger version

Name:	IMGP6318sm.jpg
Views:	15
Size:	301.3 KB
ID:	1783  

Click image for larger version

Name:	March 2015.png
Views:	3
Size:	6.0 KB
ID:	1786   Click image for larger version

Name:	Feb 2016.png
Views:	3
Size:	5.5 KB
ID:	1787   Click image for larger version

Name:	160207 70 dB 24bit.png
Views:	7
Size:	42.0 KB
ID:	1788  
rjm's Avatar
rjm
diyAudio Member
Views 168 Comments 7 rjm is offline
Old

EPSUX3v2 High performance power supply group buy list

Posted 31st January 2016 at 02:06 PM by Frex
Updated 2nd February 2016 at 03:29 PM by Frex

EPSUX3V2

High performance 160W triple outputs Lab power supply
PCB GROUP BUY


Click the image to open in full size. Click the image to open in full size.


Frex, the 31 Junary, 2016.


Hello all,

I opened here a new blog page to replace the dedicated wiki page previously
made for this group buy list.
The DIYaudio wiki is unavailable for weeks now and that will take some time
to be re-opened. So for this reason i move the group buy here on this new blog.
I will probably also take advantage of this new blog to share many others things.

Until now, 12 pre-order are done on 25 required. We will wait end of February,
and then if we stay less than 25, i will make a new price estimation for a lower batch.

Frex



The buyers list you will find below can only be updated by me, so if you...
Attached Files
File Type: pdf EPSUX3V2.1_sch.pdf (487.7 KB, 40 views)
File Type: pdf EPSUX3REGV1.1_sch.pdf (146.2 KB, 28 views)
File Type: pdf EPSUX3V2_Manual_Beta.pdf (771.7 KB, 28 views)
File Type: pdf EPSUX3V2_FULLBOM_IndA.pdf (105.7 KB, 27 views)
diyAudio Member
Posted in Uncategorized
Views 163 Comments 0 Frex is offline
Old

What are "Ground Boxes"?

Posted 24th January 2016 at 12:48 AM by rjm

Ladies and gentlemen, please try to keep a straight face while browsing the following link.

http://www.entreq.com/products/ground-boxes-17667704

I'm not sure whether its possible to build a passive, permanent device that dissipates/neutralizes electrical charge. But the scientist part of me finds the claims that you can interesting.

Static electricity will eventually dissipate by attracting counter ions from the air. This happens more quickly if the humidity is high.

So seriously, if you just stuck a wire into a bucket of dirt, how much "earthing" would that actually provide? Is there any way to amplify that effect by using special materials or even passive electrical components?
rjm's Avatar
rjm
diyAudio Member
Views 200 Comments 2 rjm is offline
Old

Ground loop noise, why it is and what you might do about it

Posted 19th January 2016 at 12:37 AM by bwaslo

I recently was motivated to figure out numerically what might be happening when you get hum out of your power amplifier only when connecting other cables to it. And why a fix I sometimes use works so well.

Before you go blowing your budget on expensive audio isolation transformers, please take a look!

http://libinst.com/GroundNoise/The%2...se%20issue.pdf

Hope someone finds this useful.

Bill
bwaslo's Avatar
diyAudio Member
Posted in Uncategorized
Views 358 Comments 1 bwaslo is offline
Old

45watts Class B

Posted 15th January 2016 at 08:11 AM by naxilla100

can anyone verify this circuit

Click the image to open in full size.

someone says the power transistors are swapped,
but it seems ok to me .....

has anyone built this circuit before .....
naxilla100's Avatar
diyAudio Member
Posted in Uncategorized
Views 195 Comments 1 naxilla100 is offline
Old

Tube-I-zator V3.1 Stock Status

Posted 11th January 2016 at 11:48 AM by dvb projekt

Dear diyaudio friends,

the last batch of the Tube-I-zator V3.1 is sold.

A new batch will be ordered, if i have 20+ pre orders.

All who want to order, please add yourself to the pre order list in the thread.


Best regards,
Oliver

dvb projekt's Avatar
diyAudio Member
Posted in Offer
Views 238 Comments 0 dvb projekt is offline
Old

Highly affordable digital audio CPU board

Posted 8th January 2016 at 04:02 AM by abraxalito

STM's lowest cost ARM Cortex M4 CPU is now available on a very low cost evaluation board here - https://item.taobao.com/item.htm?spm...cket=13#detail

Its quite a good fit for audio purposes because there are a couple of I2S interfaces with a dedicated audio PLL. There's plenty of RAM (64k) and according to the benchmarks, it'll do the equivalent of around 100MIPs. Its also respectably low power when running out of RAM - use the flash memory accelerator though and its not quite so frugal.
Attached Thumbnails
Click image for larger version

Name:	STM32F401board.jpg
Views:	77
Size:	230.7 KB
ID:	1768  
Attached Files
abraxalito's Avatar
diyAudio Member
Posted in Uncategorized
Views 277 Comments 0 abraxalito is offline
Old

Description of digital distortion meter design, with CAD files

Posted 5th January 2016 at 11:48 AM by googlyone
Updated 10th January 2016 at 06:45 AM by googlyone (Update documents)

I have been asked for the CAD files for the distortion meter I recently built.

NOTE 10 Jan 2016 : I have changed the clock driving and distribution PCB as it really needed to be more versatile to me to run a mix of CS and AKM ADC and DACs. The change allows selection of MCLK at different multiples on the ADC and DAC via jumpers on the board. Again this is prpobably a bit more "hard wired" than a generic consumer device would be, but allows stable operation for fixed sample rate systems.

WARNING:
This project is not a super straight forward "chuck it together and it will all be fine" sort of build. I am providing what is essentially a collection of USB interface (MiniDSP), power supply (mine - open source), backplane, clocking and galvanic isolation (mine - open source), A/D and D/A (mine - open source) and a differential interface and attenuator (Silicon Chip magazine), though I am strongly tempted to do my own.

...
Attached Files
File Type: zip CAD FILES.zip (3.23 MB, 11 views)
File Type: doc Distortion_Meter_Description - v2.doc (4.34 MB, 84 views)
diyAudio Member
Posted in Uncategorized
Views 286 Comments 1 googlyone is offline
Old

Repairs to Fender PD250 Complete

Posted 3rd January 2016 at 02:36 AM by tscr2015

While after about 6 months of working on my Fender PD-250 PA System, I finally got it back together tonight and it works great. I don't think that I am going to mess with it any more.

Thanks to everyone on the forums for the help and suggestions. This should be ready to rock the parade season this coming year. Right now I can vibrate the floors of my office/work area with about quarter volume.

Stay tuned to this as I work on the Hiphonics zxi1008 amp that I have on the bench now.

Till then Have a good one
Tom
diyAudio Member
Posted in Uncategorized
Views 114 Comments 0 tscr2015 is offline
Hide this!Advertise here!

New To Site? Need Help?

All times are GMT. The time now is 07:07 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2016 DragonByte Technologies Ltd.
Copyright 1999-2016 diyAudio

Content Relevant URLs by vBSEO 3.3.2
Wiki