svt vr 4 ohm into 8 ohm cabs, ampeg say don´t do it

[solitario]

svt vr 4 ohm into 8 ohm cabs, ampeg told me not todo it but if have seen many players vith vr and svt classic with ampeg 410 he cab that are 8 ohm.

I asked some tech and they told me that if the cab in 8 ohm and the amp 4 ohm there should be no problem.

are all those players with ampeg valve heads and 410 he wrong?

thank you

[Bassmec]

Originally Posted by solitario

svt vr 4 ohm into 8 ohm cabs, ampeg told me not todo it but if have seen many players vith vr and svt classic with ampeg 410 he cab that are 8 ohm.

I asked some tech and they told me that if the cab in 8 ohm and the amp 4 ohm there should be no problem.

are all those players with ampeg valve heads and 410 he wrong?

thank you

If you run an SVT into an 8 ohm cabinet using the 4 ohm tap you are stressing the output tubes because there is not enough current to pull the voltages down and the output transformer insulation might start failing, causing the dreaded shorted turn and an untimely death.
You can get away with it, but for how long? it sucks the power and it's a huge risk, don't do it.
PS did the engineer you asked get the tube amp concept or did he just give you a semiconductor based answer.
If the latter he is right. Quite a lot of young engineers have no experience with tube technology.

[solitario]

I told him it vas a svt vr... he is supoused to know svt vr are all tube amps... I hope...

[arai]

+1 to Bassmec's post
But it it is fine to do it with someone else's gear

[Bassmec]

Originally Posted by solitario

I told him it vas a svt vr... he is supoused to know svt vr are all tube amps... I hope...

He gave you a semiconductor answer so he didn't seem to understand the concept of output transformer load matching in tube amps.
Of course you could just check your cab and see if it is actually 4 X 8 ohm drivers in series parallel to arrive at 8 ohms total.
which would add up to 2 ohms if you rewired the cab all drivers In parallel.
You have an impedance tap on your VR for 2 Ohms so match it.

[derridiandrift]

Originally Posted by Bassmec

Of course you could just check your cab and see if it is actually 4 X 8 ohm drivers in series parallel to arrive at 8 ohms total.
which would add up to 2 ohms if you rewired the cab all drivers In parallel.
You have an impedance tap on your VR for 2 Ohms so match it.

Pretty sure the drivers in the 410HE are the same 32 ohm drivers from the 810E.

[CL400Peavey]

The he's use four 32 Ohm drivers I believe. Would have to source new drivers to get the cab to a 4 or 8 ohm load.

Personally I would look into a different cab, way more economical in the long run.

[Bassmec]

Originally Posted by derridiandrift

Pretty sure the drivers in the 410HE are the same 32 ohm drivers from the 810E.

If they are, it's not going to be possible.
do they still use 32 ohm drivers these days, I know my old CTS driver'd 8 X 10 was, seems odd because it must cost them in Ampeg only application terms. quantity ordered cost considerations.
That's why I said if they are 8 ohms.

[JimmyM]

If you keep the volume low, you can usually use an 8 ohm cab with an SVT without incident. But it's certainly not recommended.

[walterw]

right;

you can run your 5-speed car on the highway in 3rd gear, but is it a good idea?

[wilfredes]

Would have to source new drivers to get the cab to a 4 or 8 ohm load.

[beans-on-toast]

Originally Posted by solitario

svt vr 4 ohm into 8 ohm cabs, ampeg told me not todo it but if have seen many players vith vr and svt classic with ampeg 410 he cab that are 8 ohm.

Ampeg gave you their "official" answer. The amp should be matched to the cab for optimal performance.

People run with the bulls. That doesn't make it safe.

[ScottTunes]

In the ignorance is bliss column, I used my V-9 SVT (1976 Magnavox era) through 8 ohm cabs many times, although for relatively low volume sits... Back then I was told you could go "up or down" basically one level - meaning using an 8 ohm amp into 4 ohms, and/or a 4 ohm amp into 8 ohms (with tube heads anyway)... But matching is the best option.