Forum may be experiencing issues.

Main Menu

Show posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.

Show posts Menu

Messages - Om_Audio

Thanks for the reply. The batteries do seem to have some built in chips:
"Use Smart Universal Li-ion Battery Charger for proper charging. - Made of Four 2200m - Ah cylindrical 18650 cells with PCB and poly switch for full protection Light weight and higher energy density than any rechargeable battery Longer storage life than Ni - MH battery. No memory effect and rechargeable Built-in IC chip will prevent battery pack from over charge and over discharge and prolongs battery"

Will have to some more research- thanks-
Adapter is 14V/800Ma
not sure center pin polarity yet
(replacement adapter cheap-

14v battery packs are avail from $35-$75,or.r_cp.r_qf.&bvm=bv.73231344,d.cGU,pv.xjs.s.en_US.jy1SGYsq9dM.O&biw=1920&bih=904&tch=1&ech=1&psi=nIXuU9D7A8njoAS1j4CoBw.1408140696382.3&ei=3YXuU7nVCon7oAT25oDYCQ&ved=0COIBEKYrMAU

What is needed is enclosure and know how to connect battery correctly to ports needed for charging the battery and powering the 505. Also not sure how to equate the draw of the 505 with the capacity of the batteries in terms of run time and if it is even worth doing with battery packs in this price range.

Any assistance appreciated-

Quote from: haveyouseenhim on June 17, 2014, 09:58:51 PM
The two extra pins could be a switch.

Nope- it is a simple non-detented volume pot- no switch.
Open Discussion / REQ: Vol pot id and source to buy
June 17, 2014, 09:42:41 PM
Need to replace this vol pot on my Roland SP-404SX but cannot id it and find a place to buy-
any help appreciated-


Sent from my SM-G900T using Tapatalk


Sent from my SM-G900T using Tapatalk

Here is another observation- if I plug in this ground loop isolation transformer the noise is almost inaudible. All I do is plug in one side of the transformer- all other connections remain unused.

Also, if I plug something into the insert the noise is gone. I am wondering if a damaged component could be shorted and causing the issue. The noise id produced before the EQ and Aux secions. The XLR is normal- no noise. I am using simple 1/4" male to RCA female adapters for testing.
No it is not that, it is only on 1 channel and new issue. I took the mixer apart tonight to check solder joints of connector etc. Bunch of SMC in there. :/
I will give your suggestion a try once I have it all back together but I suspect some part in that input got damaged. I never go 3/grounded to 2/un-grounded permanently- only for trouble shooting- just not a good idea.
The manual only has a rudimentary routing schem- so I have no full service schem to offer the more experienced users here.

Had Reaper and 820i (v1) working great for years on laptops, desktops, etc.

Recently CH2 on the 820i has an odd behavior- it buzzes when you plug anything into the 1/4' input. I plugged a 1/4" to RCA adapter in when I first noticed it. If you plug a balanced cable same but if balanced cable is connected to a piece of gear the sound is still there but almost inaudible. I have recreated settings exactly on CH1 and it is silent in all scenarios as it always has been (and CH2 until recently).

I am posting a link to a zipped Reaper project with screenshots of freq display of audio examples. One screenshot here. (copy and paste link- won't let me post full link as I have not been active on these forums enough yet- less than 5MB zip file w project)

Anyone have any idea what could be wrong? I will open the unit soon to look inside- I am good with a soldering iron so if I burnt an op amp or something I may be able to repair (although if surface mounted components might be tricky)


Dropbox link to project-
Screenshot links showing frequencies:
Hey guys,
I modded 2 of my samplers to have additional outputs. I am hoping to add either piezo or reg small speakers s an option as well. Obviously fidelity will be non existant but would allow to use the machine without headphones which would be nice. Maybe if the speaker was coupled to the case or utilized a cavity I could vent could help. I also know because I am simply splitting the wires I cannot use more than 1 connection at a time without risk of overloading the headphone pre but just not sure what sots of speaker(s) I might be able to employ. I would assume the speakers would also require a switch to make sure they are disconnected when using headphones.
Any input appreciated!

Links to mods and guts:
SP-404SX headphone jack add:
SP-555 headphone jack add:
SP-404 internal mic move/improvement:
OK,  thank you very much. I was thinking same,  def place to start, will report back after I get parts and re-cap.

Sent from my HTC_Amaze_4G using Tapatalk 4

This "Dead Easy Dirt" is an awesome circuit to test diodes, caps, and ic in- very fun and I know what you mean about overtones and harmonics- they change a lot w diff diodes, caps, input/output volumes, etc.


Batteries are fine, so that rules that out.

Looks like there are a few things down the line from the mic input-

.005u cap
.1u cap
Ge tranny
3k, 10k, 40k resistors
30u cap (pol)
3k, 5k, 3k,

It all flows together, and there actually is no REC level control- just speaker volume and a variable resistor for tape speed.


Open Discussion / Re: This made me chuckle..
September 01, 2013, 12:20:27 AM
I don't get it. I'm making one now.