The No.1 Website for Pro Audio
 All  This Thread  Reviews  Gear Database  Gear for sale     Latest  Trending
DBX 160X maintenance
Old 8th May 2012
Gear Head
davide.bonetti's Avatar

Originally Posted by jumunius View Post
Hi, that's a fast turnaround. Congrats, although too bad to hear that the results don't seem worth the effort.

So I'm confused as you mentioned more caps -- had you completed all the mods you had planned when you did the listening test?

Also, might some of the mods not be more apparent on single instruments than whole mixes? Especially since some of the mods are theoretically supposed to do things like increase dynamic range and reduce noise floor, if you aren't testing on widely dynamic individual instruments you might be missing some of the benefit anyways?

Just a thought.
"more caps" in detail: since my two units were bought used and in different moments, they had all different capacitors, so I decided to replace ALL electrolithic capacitors, in addition to the modification suggestions. I am still waiting for some but everything that concerns the basic mod was done before the listening test.

it is my thought too that the mod could be more effective on single instruments, maybe. I cannot tell at home because I do not have single instrumental tracks to evaluate. I'll see in the weekend when using live.
Old 8th May 2012
Gear Head
davide.bonetti's Avatar

well, there would be one more thing: I would love to have balanced outputs on my 160Xs... but without the transformers

the user manual says something about some AB-1 option card that is fitted as a riser card onto the main board. I guess it would be a small PCB based on SSM2142 or DRV134 chip.

can anyone help me realize this option? I'd just need the circuit, then I'll think about how to assembly it.
Old 9th May 2012
Gear Head
davide.bonetti's Avatar

please see attached picture, it seems pretty straight-forward as placing the DRV134 chip and two small caps on its power lines...


how to avoid the +6dB gain on the driver's outputs?
Old 9th May 2012
Gear Head
davide.bonetti's Avatar

the picture...
Attached Images
File Type: jpg drv134.jpg (45.5 KB, 2455 views)
Old 7th June 2013
Here for the gear

i've got an ab-1 in one of my 160x. been searching hard for a second ab-1 but with no luck :(

i can take some pics of the card if you still want to build this.
Old 7th June 2013
Gear Head
davide.bonetti's Avatar

Originally Posted by t4796 View Post
i've got an ab-1 in one of my 160x. been searching hard for a second ab-1 but with no luck :(

i can take some pics of the card if you still want to build this.
yes man I would love to. if I am not asking too much, remove the card from the unit and take as much pictures as you can, both sides. many, many thanks.
Old 7th April 2017
Gear Nut
cLoudBase's Avatar

Thanks for sharing.
Just wondering how many transistors are suggested to be replaced, all 5( 3 located after U 106A/B & 2 after U103), or just the 2 after U103 single channeled OP Amp ?
Old 9th April 2017
Lives for gear

Never really was a fan of that option board compared to putting in a jensen transformer.

but i would try doing this mod since this should do the same thing. remove the two 22 ohm resistors (the ones with red x's) and jumper to the nfb network on the buffer (in green)
Attached Files
File Type: pdf 160X Schematicproposed out).pdf (1.62 MB, 78 views) File Type: pdf 160X Schematic_original.pdf (203.4 KB, 56 views)
Old 4 weeks ago
Here for the gear
Hey, gang. I know this is an old post, but I was hoping someone could explain to me what happens when you increase the original 470uf main power caps to 4700uf.

I build a lot of kits (mostly 500 series stuff) and do a lot of mods to equipment when I'm given instructions on how to do it, but I don't always know what the mods do on a scientific level. On one of my 160x's I replaced the op amps, VCA and main power caps, but with a low ESR, 105c at the original 470uf value (before finding this post). Does Jim Williams cap value recommendation increase the DC voltage, giving more headroom?

I understand that those caps are acting as filters to the bridge rectifier to get rid of ripple current (hence the low ESR), but I still haven't learned what caps and their values do entirely. I've even created passive low pass filters (1st and 2nd order. Pretty easy stuff), but that's where my cap knowledge plateaus at the moment.

I would LOVE to learn more (maybe even take a class) on electronic repair, so I can understand in more depth what components do and their relationship to each other... and be able to maintenance my own gear with confidence. So, book and class recommendations (in NYC) are welcomed.

Any input would be GREATLY appreciated.
Post Reply

Welcome to the Gearslutz Pro Audio Community!

Registration benefits include:
  • The ability to reply to and create new discussions
  • Access to members-only giveaways & competitions
  • Interact with VIP industry experts in our guest Q&As
  • Access to members-only sub forum discussions
  • Access to members-only Chat Room
  • Get INSTANT ACCESS to the world's best private pro audio Classifieds for only USD $20/year
  • Promote your eBay auctions and listings for free
  • Remove this message!
You need an account to post a reply. Create a username and password below and an account will be created and your post entered.

Slide to join now Processing…
Thread Tools
Search this Thread
Search this Thread:

Advanced Search
Forum Jump
Forum Jump