Hooked up Shiit Mani incorrectly


I feel really stupid right now. I hooked up my Shiit Mani to my phono input on my Adcom GFA 555 preamp causing both my speakers to start distorting. Once I realized my mistake I shut the system down. I believe I may have damaged both my amps in the process.  Both amps are humming when turned on. What damage could of done? Any guidance would be greatly appreciated 

horsestuff

According to Schiit no damage should of occured to the amplifiers possibly the speakers could sustain damage if the volume is set high which it wasn't around the 8 O'clock position . Also, he wrote that damage to the preamp was unlikely and should contact the preamp manufactures for more info. Not happening since they are no longer in business. With that being said I will hook everything back up and power up the system to see what happens. Hopefully I will be spared any damage.

@horsestuff 

Interested in your follow up.  Sounds like all the individual components are working OK?  Have you put your system back together to try it out?

horsestuff OP  No guarantees, but amps generally have fairly robust input circuits since they are designed to work with variable volume. They might have survived the onslaught. It's definitely a good sign that the hum is absent with no input source.

Continued to troubleshoot the amps by disconnecting the inputs to the amp leaving the speakers connected then powering up the system the hum is no longer audible. Does this mean the amps are ok?

A good place to ask these kinds of questions is the people who made the equipment.

@hickamore The engineered solution would be to use different phono-only connectors, caps that must be removed and are marked with warning statements, or other human factors safeguards.  In the nuclear industry caps are put over important buttons that should almost never be pushed.  Operators know they need to be certain whenever they flip up the caps.  Because of their design, they are referred to as "toilet seat covers".

But you have a very good point.

Jerry

Post removed 

Another good reason why preamps should not include a phono stage.

Would be an easy mistake to make for those not paying careful attention.

perkri The output of a phono cartridge is much lower than a standard line output, so it needs to be boosted for the preamp stage to be able to process it. The phono inputs on preamps and integrated amps sends the phono signal to an internal phono preamp to increase it to a line level signal. When you have no phono inputs, or a phono input with limited capabilities, an external phono amp like the Mani is used. it preforms the same function as an internal phono preamp and is intended to be connected to any available standard line input.  The OP's problem occurred because he inadvertently connected the line level output of the Mani to a phono cartridge level input that was designed for a much lower power signal. It was too much for the built in phono preamp, which probably still managed to boost it to line level just long enough to cause additional circuit overload to the main preamp.

Sorry you had this happen.

 

I’m trying to understand what you did wrong? The Mani is a phono stage, and you connected it to the phono input of your preamp?

From what you are saying, by swapping in another preamp, the phono input overload and the preamp itself are fine. And the overload zapped the input stage of your Adcom(?) monoblocs? 

Ouch!  Don't be too hard on yourself.  We have all been there.  

Not wanting to hijack your thread, but do you think home insurance would cover the damages?

I fried like that my Nak tape deck by accidentally connecting to the phono output.

I've identified quite a number of components that had been clubbed by overloading  and it was quite a number of miniature caps, transistors and diodes.

 

I swapped preamps and the problem is still there. I will swap both amps out to see if any other damage has occurred. Hopefully the speakers are ok

If you are lucky, all you fried is your phono stage.  Have you switched away from "phono", hooked up to a normal input, and still have problems?

The damage is in the input stage of your amp. You’ve just fried it.

Overloading input circuits causing the most sophisticated damages to troubleshoot pretty much.