Dayton Audio UM18 w/ SPA1200DSP Kit

[Zarkoff500]

I am looking for some assistance on troubleshooting a problem with this kit. I have been getting a very loud series of pops with auto on/off. I had sent the first SPA1200DSP back to Dayton but the second is doing the same thing. Now I am thinking it could be the UM18 which was a refurbished/restocked item.

Another piece that doesn't make sense to me is I have to set the gain on the amp at -15 db (85%) in order to get comparable output to my previous PB12-NSD and run the AVR at -2 db. Also, when running the sub auto calibration, I need to set the gain at least -25 db (75%) to have a loud enough signal for calibration.

The loud popping and high levels of gain required make me think that there is another component to this that I am missing.

Does anyone have any ideas? Anyone with this same amp, do you have to use a similar amount of gain?

Thank you sirs.

 

[agarwalro]

Another piece that doesn't make sense to me is I have to set the gain on the amp at -15 db (85%) in order to get comparable output to my previous PB12-NSD and run the AVR at -2 db. Also, when running the sub auto calibration, I need to set the gain at least -25 db (75%) to have a loud enough signal or calibration.

Different amps, different gains, different AVR settings. If there is no distortion when playing music, there's nothing to worry about.

I am looking for some assistance on troubleshooting a problem with this kit. I have been getting a very loud series of pops with auto on/off. I had sent the first SPA1200DSP back to Dayton but the second is doing the same thing. Now I am thinking it could be the UM18 which was a refurbished/restocked item.

Maybe the amp is not designed with soft turn-on capability. Kinda like when the sub is first turned on from being unplugged. Shouldn't be loud or a series of pops though. That's the only thing I can think of.

 

[Zarkoff500]

For what it is worth, I've done some additional testing:

SPA1200 with a different 4 ohm woofer with same gain and loud pops with auto off.
UM18 with SA240 amp zero auto on/off noises from driver

Next I was going to try the SPA1200 with the gain set to about 50% to determine if the high gain was contributing but I was then unable to get any output from the amp at all regardless of driver being tested. Swapped back to the SA240 and no problems. The amp turns on but now has no output.

Additionally, the wires that come from the preamp to the amp aren't 100% seated but are glued in place. Not sure if this could contribute. See photos for reference.

Finally this is a link to what the shutdown pops sound like from about 15' away.

 

[TLS Guy]

I would say the SP 1200 is junk then. There is a lot of it about these days.

 

[Zarkoff500]

It is unfortunate if that is the case as it has such potential with the DSP. However, Dayton does not seem to have been putting continued support into that feature. No updates that I am aware of, IOS support only, and the inability to use the PEQ below 20 hz where the SPA250/500DSP models both do down to 10 hz.

 

[Zarkoff500]

A slight update to this thread as I am waiting for my third amp. PE is certain the popping was due to the high gain used based on their testing. Before sending out the replacement, they say thorough testing will be done. Hopefully I won't have to manually turn the sub on/off once the replacement is received.

 

[Zarkoff500]

Probably the last update since I know many were keen to see the outcome of this thread .

This was their reply after additional testing:

"Thank you for your patience. I feel that it would be best to issue a refund at this time. We have identified some things that we do not feel meet the quality that we expect from Dayton Audio and we would like to get this item looked at in better detail before we ship another amp.



Sincerely,

Technical Support Team"

PE did not go into detail as to the QC items identified but the amp is now listed as Out of Stock at PE. Not sure what is going to happen with flat pack as it has cut outs specifically for this amp and control module. It would either have to be modified or replaced.

 

[lovinthehd]

Interesting. Hopefully they'll help you out with the box or amp soon. Curious, some reason you prefer a plate amp?

 

[Zarkoff500]

It was part of the PE kit, UM18, flat pack and amp. Mostly for convenience plate amp vs passive. They are now going to try and replace it if the QC areas are addressed. Just stinks that I am going months without a useable product. In the future, I would likely go the inuke route.