Help with replacing Ampeg 810 input plate

T

terwilliger

Nov 23, 2024
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#1
Hi everyone,
Been reading opinions on TalkBass for a long time but never signed up until now. Need guidance.
Main rig is a Sansamp pre to a QSC 2450 bridge mono amp, cab is an Atlas 4x15. Speakon out of QSC is wired +1 +2, Atlas has a 1/4" input. Works great.
The cab i use in the practice room is an Ampeg 810 classic. The input plate/jack fried on me recently. I found out that the plate was for a single 15 cab (yes I bought it on craigslist but hey it lasted 10 years without an issue).
Here's my questions:
Can an Ampeg 810 handle bridge mono (+1+2)?
Does anyone have a wiring diagram for an Ampeg 810 (jack plate #16-764-02)?
The Atals cab is power hungry, it only sounds good if you push it. Is bridge mono (+1+2) to 1/4" okay to do? How else could you provide a 2000w cab without solid state bridge mono?
Thanks again! Please excuse my tech ignorance. I'm a plug and play kinda guy
 
#2
The 1/4 inch jack burned up from the excessive current.

What cab burned has the burned up 1/4 inch jack?.......That may have acted as fuse and saved the cabinet!!

When you say 810 Classic do you mean an original Ampeg SVT 8x10 cabinet or the newer "classic" series.

With Speakons at each end the amp end will be wired 1+ 2+ the speaker end wired 1+ 1-. The 2+ connection becomes the 1- at the speaker end.
 
#3
Way too much power for an Ampeg 810. It’s a 4 ohm load and the amp is rated at ~2400 watts bridged into 4 ohms.

1+/2+ is only used at the amp end of the cable, 1+/1- is used at the speaker end in all cases.
 
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#4
Thanks for the responses! I'm aware that I'm overfeeding the ampeg cab running bridge mono but I really don't want to have to change the DIP switches everytime I switch to the Atlas cab for a show. I have plenty of head room, is it still bad for the ampeg 810 if volume is at 40%?
Also @Mike it's an old SVT810.
 
#5
What does the jack plate look like?

Modern 810s have a jack plate like this.
1732395296778.png


This is the Heritage version, but the standard version looks pretty much the same. Full Compass offers both the Heritage and standard version.


Wiring is discussed here: https://www.talkbass.com/threads/jack-plate-for-ampeg-svt-810e-classic.1560918/
 
#6
terwilliger said:
Thanks for the responses! I'm aware that I'm overfeeding the ampeg cab running bridge mono but I really don't want to have to change the DIP switches everytime I switch to the Atlas cab for a show. I have plenty of head room, is it still bad for the ampeg 810 if volume is at 40%?
Also @Mike it's an old SVT810.
Click to expand...
Just be very careful and run with a 50Hz HPF.
 
#8
terwilliger said:
I'm aware that I'm overfeeding the ampeg cab running bridge mono but I really don't want to have to change the DIP switches everytime I switch to the Atlas cab for a show.
Click to expand...
I doubt you'd need to change the DIP switches to use just one channel of the power amp -- just feed your speaker from the output of only the left channel amp. Leave the DIP switches where they are -- all they are doing is routing (and inverting) the input signal. The left channel would still work normally. IMO 2400 watts RMS is just too dang much power for an old 'fridge. If it's not yours, you're risking blowing up speakers in someone else's cab.

Edit: Also, if the cab is old enough to have an XLR input connector, a Speakon NL4 is just a drop-in replacement. And as indicated, use the +1 and -1 terminals in the connectors on the speaker end.
 
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#9
Redbrangus said:
I doubt you'd need to change the DIP switches to use just one channel of the power amp -- just feed your speaker from the output of only the left channel amp. Leave the DIP switches where they are -- all they are doing is routing (and inverting) the input signal. The left channel would still work normally. IMO 2400 watts RMS is just too dang much power for an old 'fridge. If it's not yours, you're risking blowing up speakers in someone else's cab.

Edit: Also, if the cab is old enough to have an XLR input connector, a Speakon NL4 is just a drop-in replacement. And as indicated, use the +1 and -1 terminals in the connectors on the speaker end.
Click to expand...
That trick would work, the Speakon cable at the amp would need to be then wired 1+ 1-.

If it is the old single connector cabinet use a NL4MP Speakon connector, those have a larger round mounting flange.
 
#11
Mike Caldwell said:
...use a NL4MP Speakon connector, those have a larger round mounting flange.
Click to expand...

Actually, NL4MPR is the part number for the Speakon with the larger, round flange. 'R' is for 'Replacement', as this was intended to be a direct replacement for the panel mount EP and AP series Cannon connectors. But the part number @Mike Caldwell gave, NL4MP, is the right one for a direct swap with a regular ol' XLR-3 connector. Mike is right -- if you don't actually need the smaller form factor of square-flange ones, the larger, round-flange connectors are easier to attach securely to a panel, or more importantly, directly to a wood cab.
 
#12
Redbrangus said:
Actually, NL4MPR is the part number for the Speakon with the larger, round flange. 'R' is for 'Replacement', as this was intended to be a direct replacement for the panel mount EP and AP series Cannon connectors. But the part number @Mike Caldwell gave, NL4MP, is the right one for a direct swap with a regular ol' XLR-3 connector. Mike is right -- if you don't actually need the smaller form factor of square-flange ones, the larger, round-flange connectors are easier to attach securely to a panel, or more importantly, directly to a wood cab.
Click to expand...
I described the R version but left the R off the part number!!! The R version would be easier to retro fit. If I'm not mistaken I think the originals used the round flanged style XLR connector.
 
#13
Holy crap! Thank you guys so much for all the info. Much appreciated 🤘 Imma dive into my rig using your suggestions. Like I said earlier I'm a plug and play guy, we play very low and very loud even at practice. After troubleshooting I'll let y'all know which one blows first, my cab or my drummer's ears lol.
Thanks again!
 
#15
Absolutely agree with agedhorse here. The old 810 fridge was designed to roll off at 80hz (or cps if you're talking old specs). The very low end was suppressed to allow the SVT package to cut through when facing full Marshall guitar stacks. It was intentionally not "wasting" amp power on the very low end to rattle stages. In those days you were barefoot as the PA systems struggled to provide vocal and maybe some of the drum kit.
 
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#16
Like I said earlier my show cab is an Atlas 4x15 2000w RMS. We practice in a basement and realized very quickly that our old asses are going to end up breaking an ankle or something taking that beast up and down rickety stairs. The SVT 810 stays in the basement for practice, I just want it to be somewhat close to what we sound like live when writing songs.
I also have an Ampeg 1x18 in storage. Could I daisy chain the 810 to the 18 to help bridge mono work better?

Thanks again guys
 
#18
terwilliger said:
Could I daisy chain the 810 to the 18 to help bridge mono work better?
Click to expand...
You can't do that because the resultant impedance would be too low for the amp when it's in bridged mode. You could run the two different speakers in 2-channel (parallel) mono mode, but what a lotta grief for your basement practice room. IMHO, of course. :smug:
 
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#19
terwilliger said:
Like I said earlier my show cab is an Atlas 4x15 2000w RMS. We practice in a basement and realized very quickly that our old asses are going to end up breaking an ankle or something taking that beast up and down rickety stairs. The SVT 810 stays in the basement for practice, I just want it to be somewhat close to what we sound like live when writing songs.
I also have an Ampeg 1x18 in storage. Could I daisy chain the 810 to the 18 to help bridge mono work better?

Thanks again guys
Click to expand...
At least you will be so deaf that won't be able to hear each other scream in pain when you break your ankle...

Sure you can parallel the 18" cabinet, you can do anything you want, but the amp won't very last long.
 
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#20
Really appreciate the input guys, thank you for everything!
I knew this thread would turn turd eventually but I got some good suggestions from what I can only assume are seasoned bassists.

Gonna delete my profile now. Don't understand why haters be hating. I think it's a nerd complex, except for the fact that it doesn't have to be.

Have fun, be yourself, and make music. Thanks again for everything.
 
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