Ampeg SVT-CL

[Jazz P Bass]

Ho Hum.

[soundguruman]

It seems to work OK with "semi matched" tubes.
We mixed 2 Sovtech with 4 Svetlana, and it kept going and going...

Chicken Soup = Jewish Penicillin.
Eat lots of it.
Get better soon dude.

[soundguruman]

Ho Hum.

No, not very exciting, is it?

[Leo_Gnardo]

I also noticed that there were two spade connectors(flag shaped), that were badly corroded from overheating over time......I have two new ones here now to install as well.

Those are almost certainly the filament connections. Spade connectors good for 10-15-maybe 20 amps. I cut 'em off and securely solder the filament wires onto the PC lands. PC design engineer "sorta forgot" that a current pulse on startup is the norm for filaments - I've measured 6x compared to "warmed up". For a circuit that normally uses 10-12 amps of filament, that's what, 60 to 72 amps. It's all over in a fraction of a second but no matter - spade connectors can't take that. Same problem noted in Fender/Sunn 300 bass amps.

[Jazz P Bass]

I was not refering to IT.
U.

[Mick Bailey]

Later, the factory closed, and production moved to China. But, still same amp...

The ones we get here are all made in Vietnam - not seen a Chinese one.

[bsco]

Just checking through all those service bulletins and looking at the sequences of serial numbers, the number I have here does not appear on the list...The number I have starts off with EFRDU then it has 5 sequential numbers...... So do these bulletins also include this amp as well ??? Sorry for all these questions but I just want to make sure...I don't want to do mods if this particular serial number does not call for it.......god only knows what will happen.....I feel it is better to be safe than sorry....

[MarkusBass]

This is as simple as checking whether you have 22 ohms resistors on the board. I know that taking out the power board takes some time but since you have open resistor there, you have to do it anyway.

Mark

[bsco]

Looking back at post #1, I have this unit all dis-assembled...There are 22 ohm resistors installed there...rated for 1 watt...it still has the diodes installed as well...I have replaced two flag terminals on the underside of this board... ( the ones with the two white wires attached)....The serial number of this unit does not coincide with those on the service bulletins...which is why I had posted that last question...sorry if I have confused you as you are assuming that I do not have this unit dis-assembled....Once again, I thank everybody for their input....I learn much from this forum......
Cheers,
Bernie

[bsco]

Hi Mick. Just for the fun of it, I double checked this amp's origin and it is made in Korea....

[Enzo]

It doesn;t matter if your serial number made the list or not, the circuit is the same. The affected serials just are from the period of time they know they were installing the old parts. If your amp is not updates to 220 ohm it should be.


Guruman likes to spout the same old tiring rant about Ampeg being made by the same company that makes Crate. SO what? Cadillacs are made by the same company that makes Chevrolets.

SLM used to make their electronic products in the USA. Crate didn't make Ampeg, SLM did. Just as Cadillac doesn;t make Chevy, GM does.

Don't take my word for it. Here, watch this video of them making the amps. Don't look or sound very Chinese to me.

Building a Heritage - Ampeg Heritage SVT Series - YouTube

[bsco]

Ok Enzo...I'll cut out the diodes and install 220 ohm 1 watt resistors...I gave the socket associated with the bad tube a very good inspection and it looks fine...no signs of overheating and carbon tracks anywhere. I'll give all the sockets a good cleaning with some De-Oxit....I'll use guruman's suggestion for testing with one set, then two and finally all of them...everybody here is great...they spend a lot of time here helping out people like me.....it is much appreciated......
Cheers,
Bernie
P.S. Used to have a 74 Cadillac DeVille.....great car....like floating on a cloud....murder on gas....
Had a look at that video...quite the set-up there...

[bob p]

I own a pair of SVT-2 Pro. One of the was manufactured by SLM and made in the USA. The other was the same SLM design but manufactured in Korea. I've taken both amps apart to the point that I had all of the boards and transformers out. While I was repairing some other problems that happened during shipping I decided to recap the amps, just on the basis of their age. It seemed like it was worth the cost to spend a few bucks and do this while I had the amps apart, because time is money.

While I had the two amps apart I had an opportunity to make detailed comparisons of quality of the boards, quality of the passive components, quality of the caps, etc. I even had a chance to blueprint the transformers (non-destructive testing only).

I can tell you with complete confidence that there is NO DIFFERENCE in quality between the USA-made SLM amps and the Korean-built "Crate Pegs." Anyone who suggests differently is talking out of his butt.

[MarkusBass]

I noticed the same regarding SVT3Pro. The ones manufactured in Korea were of the same or better quality then the older ones made in the US. They had also some adjustments (improvements) that were not present in the older version. It would be nice that SGM knows the difference between China and Korea - this is not the same country. It's like confusing the US with Cuba. On the streets there are a lot of american cars but this is not the same country (check on the Wikipedia if you don't believe).
I'm also curious which Ampeg amps is this "good-old-real-american" amp. If Ampeg SVT Classic is not, can you name the correct ones? Do you mean SVT HD Skunkworks? Some of them for a short period of time were manufactured in Japan. Or you mean Ampeg B-15, or SVT VR? I'd like to know the list - it looks that it is very short (according to SGM).

Mark

[bsco]

Thanks bob p...and Mark......Yes this amp is built like a tank...and the workmanship is not like the other cheap junk I get to work on....I'll check out the filter caps while I have it apart as well....thanks a bunch.....
Cheers,
Bernie