Ampeg SVT-II appreciation thread - Page 39

JimmyM · #**761** 12-21-2012, 12:08 PM

I'd like to know what your source is for these 210w SVT's. SVT's in proper working condition hit their marks no problem. Tubes might get weakened a little over the years, but failing that, they should hit their marks.

tbird36go · #**762** 12-21-2012, 12:28 PM

Quote:

Originally Posted by JimmyM

I'd like to know what your source is for these 210w SVT's. SVT's in proper working condition hit their marks no problem. Tubes might get weakened a little over the years, but failing that, they should hit their marks.

Just stacking the numbers together as I go from tube spec sheets. The tube store, tube depot, euro tubes, wiki etc. I just dont see how 6-6550s in an SVT can put out the same 300 watts as 6-kt88s in a SVT when they are different watt tubes? Am I missing something here? Does the output tranny have something to do with it? Will a higher watt tube just open up more clean headroom vs. early breakup?

JimmyM · #**763** 12-21-2012, 12:30 PM

You're asking me?

tbird36go · #**764** 12-21-2012, 12:43 PM

Quote:

Originally Posted by JimmyM

You're asking me?

Lol, you or anyone else on here. I wana know how wrong I am because I dont wana muck things up. I gota deal with some real loud band members & I mean real loud! I want all the raw power I can muster outa the beast.

tbird36go · #**765** 12-21-2012, 01:07 PM

Johnathan Herrera of BP magazine says the output transformer is the main interface between your amp & speakers & has a large influence on sound because of different winding arrangements, amount. & quality of copper & iron etc. This is one of the main reason I may. Hange to a new tranny. They degrade over time & start to muck up your amps performance

JimmyM · #**766** 12-21-2012, 01:24 PM

Quote:

Originally Posted by tbird36go

Johnathan Herrera of BP magazine says the output transformer is the main interface between your amp & speakers & has a large influence on sound because of different winding arrangements, amount. & quality of copper & iron etc. This is one of the main reason I may. Hange to a new tranny. They degrade over time & start to muck up your amps performance

The one in my 69 SVT isn't degraded whatsoever, and considering how it was treated before I got it, if any trannies should degrade, it's that one.

tbird36go · #**767** 12-21-2012, 01:33 PM

Quote:

Originally Posted by JimmyM

The one in my 69 SVT isn't degraded whatsoever, and considering how it was treated before I got it, if any trannies should degrade, it's that one.

Thats cool I hope mine checks out OK. If its good to go I might just pop in some JJ KT88s & call it a day.

Dave M · #**768** 12-21-2012, 03:30 PM

Quote:

Originally Posted by tbird36go

Average plate dissipation rating of 6550s is 35W, KT88s is 42W, KT90s are 50W & KT120s are 60W. I'm no math magician but it seems to me if you run 6 6550s in a SVT you would push about 210+ Watts or you could drop in KT88s for 252+ watts so on & so on. I wana run KT120s at 360+ watts & this is where the new tranny comes in. I sent an email to Mercury so i'll se what they have to say about it. I know tubes give a little more power in the push/pull they do but not a ton more. I could be totaly wrong about all this but I spend alot of time reading specs with my OCDisum. A guy at Watford Valves in Hertfordshire, England swears by the KT120s & runs them in his SVT. I don't know if hes done any mods to it but Im gona find out.

You are quoting specifications. Many times with tubes they operate outside of their design parameters. Many times successfully, sometimes not

.

Quote:

Originally Posted by tbird36go

Just stacking the numbers together as I go from tube spec sheets. The tube store, tube depot, euro tubes, wiki etc. I just dont see how 6-6550s in an SVT can put out the same 300 watts as 6-kt88s in a SVT when they are different watt tubes? Am I missing something here? Does the output tranny have something to do with it? Will a higher watt tube just open up more clean headroom vs. early breakup?

Tube vendor data, which *hopefully* is reliable.
The SVT runs a relatively high plate voltage which is necessary to get the 6550s to produce their max. It also supplies a good amount of current at those voltage to keep up with the electrical demand even WHEN THE AMP IS RUNNING FLAT OUT. As I said earlier, the power supply must be able to properly deliver voltage and current to produce the power.

(There are 4xEL34 amps that can produce clean 120w RMS, too. But that tube is *rated* for only 25w max.)

Does the SVT-II even have the capability to:
1) Safely operate the KT-120?
2) Produce the claimed (thank you, NS) output of the KT-120?

Quote:

Originally Posted by tbird36go

Johnathan Herrera of BP magazine says the output transformer is the main interface between your amp & speakers & has a large influence on sound because of different winding arrangements, amount. & quality of copper & iron etc. This is one of the main reason I may. Hange to a new tranny. They degrade over time & start to muck up your amps performance

Yes, the OT has a significant influence on the sound, feel, frequency bandwidth.

The OT degrades over time? Who said this, and why?
If a mishap occurred in the amp, it could damage the OT. But, under normal operation this sounds like pure BS.

Quote:

Originally Posted by tbird36go

Thats cool I hope mine checks out OK. If its good to go I might just pop in some JJ KT88s & call it a day.

That may be all that you need, or you may need nothing at all. For example: 320w vs 270W in your amp. Will you hear or feel the difference, all else being equal?
BTW, how much power is it actually producing right now?

SactoBass · #**769** 12-21-2012, 03:42 PM

I just purchased an Ampeg SVT II (nonpro) from a guy in the midwest, and it is currently on the UPS truck on its way to me.

It's in fantastic condition and I got it for a smokin price. The only thing the amp is missing are the little white plastic covers that go on the ends of the EQ sliders (his 3-year old nephew took them off a while back, never to be found again).

Would any of you happen to know where I could buy a set of those thingies?

Thanks.

JimmyM · #**770** 12-21-2012, 03:50 PM

Quote:

Originally Posted by SactoBass

I just purchased an Ampeg SVT II (nonpro) from a guy in the midwest, and it is currently on the UPS truck on its way to me.

It's in fantastic condition and I got it for a smokin price. The only thing the amp is missing are the little white plastic covers that go on the ends of the EQ sliders (his 3-year old nephew took them off a while back, never to be found again).

Would any of you happen to know where I could buy a set of those thingies?

Thanks.

Holy cow, good luck with that one! EQ slider thingies are some of the hardest replacement parts to get for any amp.

SactoBass · #**771** 12-21-2012, 03:55 PM

Quote:

Originally Posted by JimmyM

Holy cow, good luck with that one! EQ slider thingies are some of the hardest replacement parts to get for any amp.

Yeah, if I don't have any luck finding real Ampeg slider covers, I might look elsewhere such as hardware stores, electronic parts stores, etc. They strike me as being something that is fairly generic.

JimmyM · #**772** 12-21-2012, 04:00 PM

Well at least the metal part didn't break. That's when you're really in trouble.

SactoBass · #**773** 12-21-2012, 04:02 PM

Quote:

Originally Posted by JimmyM

Well at least the metal part didn't break. That's when you're really in trouble.

For sure!

Fortunately, the eq sliders themselves are perfectly fine. I just need the white plastic (or PVC) covers that go on the end of each slider.

This place might be able to help me:

http://www.stockcap.com/pvc-caps.html

The rectangular caps look promising.

JimmyM · #**774** 12-21-2012, 04:43 PM

Ya, that would be my guess for your best bet, too.

tbird36go · #**775** 12-21-2012, 05:24 PM

Thanks for all the info & calming of my nerves but the head hasn't even reached me yet its on its way FedEx. That's the kind of guy I am I need to know damn near everything before I touch something. I've been working on & building basses for years but never did any major amp tweaking other than rolling tubes & speaker wiring. This may just be the OCD project I've been looking for. I might overdose on this head just to see what happens. Nobody else on this forum is doing it so why not be the first. Im also in the process of preping my 810E to get a coat of LineX. Lots of projects ill keep everyone posted.

tbird36go · #**776** 12-21-2012, 05:27 PM

Quote:

Originally Posted by SactoBass

Yeah, if I don't have any luck finding real Ampeg slider covers, I might look elsewhere such as hardware stores, electronic parts stores, etc. They strike me as being something that is fairly generic.

You can always use the "Plasti Dip" from Lowe's. I used that on some ancient acoustic sliders.

**haystack55** · #**777** 12-22-2012, 03:05 PM

Quote:

Originally Posted by JimmyM

Holy cow, good luck with that one! EQ slider thingies are some of the hardest replacement parts to get for any amp.

sucks that they're often the 1st things lost.

**haystack55** · #**778** 12-22-2012, 03:07 PM

i wonder if these might work:

http://www.ebay.com/itm/Equalizer-pe...item3ccc8c53fe

Primakurtz · #**779** 12-22-2012, 07:54 PM

Quote:

Originally Posted by tbird36go

You can always use the "Plasti Dip" from Lowe's. I used that on some ancient acoustic sliders.

I was going to suggest that, but it would be really difficult to hold such a heavy amp upside down while the stuff dries...

greengoblin · #**780** 12-22-2012, 08:16 PM

Check out your local auto parts stores and look at the vacuum caps that close off ports. I have seen some of those that are similar....

Or LOUD parts: 1-(800)-258-6883 ??