why the hell do i keep blowing my speakers

[jeff7bass]

More gain, less master

Yes master... I mean less master, master!

 

[agedhorse]

Had your amp been properly troubleshot by a QUALIFIED service tech, you wouldn’t have paid for repairs that your amp did not need.

Perhaps if you think you are having problems with your speaker cabinet, you seek the help of a QUALIFIED Ampeg service center so you don’t pay for more repairs that you don’t need.

 

[JeezyMcNuggles]

i have already replaced one and i can tell another speaker is about to go. I dont even play all that loud. my gain is 1/4 the way up and my volume is about 3/4+.
my gear is

ampeg svt 2 pro
RMS Power Output (4 Ohms): 300-Watts
RMS Power Output (2 Ohms): 300-Watts
Preamp: Tubes (4 x 12AX7, 1 x 12AU7)
Driver Tubes: 1 x 12AX7, 2 x 12AU7
Power Amp: Tubes (6 x 6550)
Tone Controls: 3-Band
Mid Tone Control: 5-Position
Graphic EQ: Yes, 9-Band
Ultra Low/High Boosts: Yes
Balanced Line Out: Yes, Pre/Post (transformer)
Effects Loop: Yes
Preamp Out/Power Amp In: Yes
Slave Out: Yes
Dimensions (W x H x D inches): 19 x 7.5 x 15.75
Weight: 70 Pounds

ampeg 410 hlf
LF Drivers: 4 x 10”
Voice Coil: 2”
Magnet Weight (each): 30 oz
HF Drivers: Horn/Driver
Voice Coil: 1”
Magnet Weight (each): 8 oz
RMS Power Handling: 500-Watts
Frequency Response (-3dB): 48Hz-18kHz
Usable Low Frequency (-10dB): 28Hz
Nominal Impedance: 4-Ohms
Sensitivity: 98dB
Maximum SPL: 125dB
Dimensions (W x H x D inches): 24 x 30 x 19
Shipping Weight: 110 Pounds
Handling Weight: 85 Pounds

the settings on my bass are : volume all the way up/ bass half and trebble is half.

am i missing simething important here? my amp will clip only when i really hit the strings hard , but i almost never do that.
please !!!!
thanks for ur time

Do you have a picture of the supposedly blown speaker? What do you mean by blown? Is there fire damage? Or is the speaker in more than one piece?

 

[JeezyMcNuggles]

I don't know your particular amp...but...my thoughts...

The first, MOST important thing is to pull out the owner's manual and READ it carefully. The absolute first thing I do when acquiring any piece of equipment is to get the owner's manual, even if I have to buy one.

In general, I have always found it good to run the preamp up high - but not into overload or clipping. This allows you to run the Master (output gain) lower, which is easier on speakers.

Boosting bass frequencies adds greatly to the load your speakers have to handle. If you have been boosting low end frequencies, turn them down and use more mid-range frequencies.

Finally, if you're having trouble hearing yourself with an SVT cranked up and a 4x10, either your preamp (Gain) is MUCH too low, or your band is too loud. You can always add a cab - like a single 15 - and get plenty of low end out of it.

No. He can't hear himself because he's using a cab that naturally scoops his tone. And he's also scooping the heck out of his eq. He's probably also using two pickups (which scoops your tone)

 

[JeezyMcNuggles]

do i not have enough headroom? i am useing SO to 1/4 inch cable, and a monster instrament cable. it isnt the power amp that is peaking its the pre amp.

Turn off the ultra high and low. Flatten your bass eq. Gain should be around 10 oclock. Master wherever you want it. That cab is naturally scooped, so you'll have to boost your mids to get any sort of volume. The problem isn't your amp, or your cab. The problem is that your scooping your bass right out of your sound. You're blowing speakers because of low end power. That cab already has boosted low end, which covers up your tone. Therefore making you seem quiet. You're not. Dropped speakers are there to prove that. You just can't hear it because you have no tone. Your bass is pretty much non existent in a group setting.

 

[byacey]

Take your blown speakers to a qualified speaker reconer. He'll be able to tell you exactly why the speakers are failing. You might not like the answer.

 

[rickdog]

Welcome to TalkBass! We try to give helpful advice....

I bought a used classic (made in USA.) It had a nasty hum. I assumed it was tubes so I bought new tubes. Hired a tech to install them. He set the bias to factory recommendations. Still hum. He replaced all the caps. Still hum.

Don't take your amp back to this tech. It really sounds like he was just guessing.

Read online that this is a problem and to ignore factory recommendations for bias and bias to ear. No hum.

If the amp is in good working order, biasing according to the procedure in the owner's manual will work correctly and hum will be minimal. You can fine-tune the bias to minimize the hum, but both bias lights must stay only green (no red). (I have an SVT-CL, I've done it and can personally attest to it.)

On the other hand, if the amp isn't in good working order (which yours apparently wasn't) biasing "to ear" and ignoring the bias lights can lead to damaging the amp.

You can read a lot of things online. You have to use some judgement about which things to believe.

I was playing. All of the sudden the amp sound shut off. Turned amp off and back on. It started working again.

If you damaged the speaker, how did turning the amp off and on make it start working again?

The SVT-CL has a protection circuit that detects excessive current in an output tube and shuts off the high voltage. Turning the amp off and on resets the protection. When it goes into protect mode, the standby light on the front flashes red and green, did you notice if yours did this?

Now I realized I can crank the master all the way up and it's actually a comfortable volume standing next to the amp. Plugged in a guitar to make sure it wasn't my Warwick bass. The d string on the guitar makes the guitar fufufutter sound.

This could be a damaged speaker... or it could be a damaged amp. @agedhorse knows his stuff, and gives good advice. Find yourself a competent tech who can diagnose the problems (my guess is there's more than one problem by now) by methodical troubleshooting.

 

[Wasnex]

I am having the same problem. I bought a used classic (made in USA.) It had a nasty hum. I assumed it was tubes so I bought new tubes. Hired a tech to install them. He set the bias to factory recommendations. Still hum. He replaced all the caps. Still hum. Read online that this is a problem and to ignore factory recommendations for bias and bias to ear. No hum. I get the amp. I have the Ampeg HLF 4x10 also. I keep the MASTER as low as it will go but gives me some umph. Like 9 o'clock. The gain is cranked to 2 o'clock ish. I was playing. All of the sudden the amp sound shut off. Turned amp off and back on. It started working again. Now I realized I can crank the master all the way up and it's actually a comfortable volume standing next to the amp. Plugged in a guitar to make sure it wasn't my Warwick bass. The d string on the guitar makes the guitar fufufutter sound. Not a drop D. A middle string. I paid over $900 plus $500 in maintenance. I think the cab I bought used was $500. Really heart broken.

The CL has a protection circuit that forces the amp into standy if one of the output tubes pulls too much current. You have to turn the amp off to reset the circuit. The SVT is prone to blowing screen resistors, so if the amp went into protect mode, and now it can't be biased...time for a tech.

Ignoring the factory bias recommendations is not a good idea. If the red LEDs are on for either bias sense circuit, it means one of the tubes is pulling too much current. That does not mean you cannot bias the amp by ear to some degree, but there are limits.

This amp has the tubes organized into two circuits of three tubes. Let's call them circuits A and B. The plate voltage is fed to the center tap of the primary of the output transformer. From there it travels in two directions to the outer windings. Circuit A is connected to one side of the transformer and circuit B is connected to the other side of the transformer.

Current flows through the tubes in circuit A. From A, current flows to the C where it is returned to the power supply.

The same thing happens with Circuit B. Current flows through the tubes. From B current flows to C where it is returned to the power supply.

The part you are doing by ear is balancing the current so it is equal in both sides of the transformer. In other words the current from A to C is equal to the current from B to C. When this condition occurs the hum balances out. It's okay to do this, as long the red bias indicators do not come on.

This amp has a bias sense circuit for both circuit and A and circuit B. But the status of the LEDs does not tell you when the current is balanced in the transformer.

I found this online and believe it is a good representation of how the bias sense circuit operates. The amp has two of these circuits. Each circuit monitors three tubes.

First you have an "And" logic function for the green LED. The "And" logic function requires all three tubes in the circuit to pull more the 15mA of current before the green LED will turn on.

Second you have and "Or" logic function for the red LED. The "Or" function is satisfied when one or more of the tubes pull 30mA or more current.

So if the tubes were perfectly matched, the total current to turn on the green led would be 3x15mA=45mA. Unfortunately tubes are rarely perfectly matched. So you might have something like 15mA, 24mA, 22mA in circuit A (61mA total). In circuit B you might have something like 26mA, 28mA, 15mA (69mA).

Notice the green LED just barely turns on in each circuit because one tube in each circuit has just passed the 15mA target. Also notice that the current passing through each side of the transformer is not balanced (I.E. 69mA is not equal to 61mA), so you will probably have a dull hum. The solution is to increase the total current in circuit A to 69mA. As long as this does not cause a red LED to light you are still following the recommended bias procedure. For example if the tube current in circuit A is increased from (15mA, 24mA, 22mA) to (17mA , 27mA, 25mA) you are fine.

But if the current in the middle tube really jumps up, for example, (16mA, 30mA, 23mA), then you have a problem. Notice in this example, we have balanced out the current at 69mA, but since the middle tube has hit the 30mA target, the red LED will turn on to tell you one of the tubes is running too hot.

I don't know the target for the fault circuit, but if one of the tubes pulls a massive amount of current, it will force the amp into standby in an effort to try and prevent damage. If you continue to operate the amp with a problem that is causing the fault circuit to engage, there is a good chance that collateral damage will eventually occur.

 

[chaosMK]

If the cab is farting then you need more cabs or roll back the master. Maybe roll back bass or cut the lowest a good bit on GEQ.

Huh, I've had my controls relettered to go to 12... Makes a HUGE DIFFERENCE in volume.
BOB

I relettered my knobs into universal "Clock" format.

 

[Fishheadjoe]

Once you have everything in proper working order, I highly recommend that you consider a High Pass Filter if you want to keep that 4x10 in working order. I would also suggest that you look into an additional 4x10 to ease the pain your single cab is feeling.
IMHO, you are asking too much from a single 410 and given that most 4x10's will blast the crap outta your knees and ankles, it's giving everything is has and you are missing most of it!
Fishheadjoe

 

[RavenTenderfoot]

The SVT-CL has a protection circuit that detects excessive current in an output tube and shuts off the high voltage. Turning the amp off and on resets the protection. When it goes into protect mode, the standby light on the front flashes red and green, did you notice if yours did this?

Yes. This did happen. Ironically, after this happened, the battery in my bass was dying. I assume that is why the sound was so low. It put in a new battery and it solved it. But I did get freaked out about the amp dropping in power before that happen. Just now I was recording a very low volumes and the amp dropped in volume twice. The first time I thought I hit something on the recording chain. Couldn't figure out what and then it did it again. It slowly came back up. But, yeah, it needs to be biased properly.

 

[RavenTenderfoot]

The CL has a protection circuit that forces the amp into standy if one of the output tubes pulls too much current. You have to turn the amp off to reset the circuit. The SVT is prone to blowing screen resistors, so if the amp went into protect mode, and now it can't be biased...time for a tech.

I'm thinking this is the best solution.

 

[RavenTenderfoot]

I watched this video on biasing. The 2nd bias does not light up at all. I turned it all the way in both directions. So, something is screwy.

 

[AxtoOx]

Big amp.
Had a nice Eden do the same thing, but,only one speaker and it was cool so....

 

[RavenTenderfoot]

Is there any audible way to tell if the output transformer is bad?
I see they run about $300 bucks for the Heyboer and $307 for an Ampeg. The Heyboer is USA made. No idea about the Ampeg.
If the output transformer is bad and a new one takes a few weeks to arrive, will recording with the amp destroy more than just the already bad output transformer? I'm expecting a "hell ya!" Can I get a "hell ya?"

 

[RavenTenderfoot]

I'm mean, I'd be reasonable... and keep a fire extinguisher handy. Duh.

 

[Lobster11]

Y'all realize you're responding to an 11-year-old post and OP hasn't been seen since 2012, right?

 

[byacey]

Yep, but another poster indicated he was recently experiencing the same problem. Better to keep it all in one thread so we don't reinvent the wheel when someone has a similar problem.

 

[S-Bigbottom]

Is there any audible way to tell if the output transformer is bad?
I see they run about $300 bucks for the Heyboer and $307 for an Ampeg. The Heyboer is USA made. No idea about the Ampeg.

Stop throwing parts and money at something it may not be, like you already have with the tubes and capacitors.
Give it to a Qualified Ampeg Repair Center and let them find what is really going on. Do not tell them to replace the whatever you think or read on line parts.
Let them find and fix what is really needing fixing.
They will find it.

Some do not mind putting in new parts someone asks for, They should fix it right the first time but the bill for new caps or tubes looks good. Sounds like your guy is one of them.

Also have your cab checked out, something may be wonky there from the previous owner. This would have your amp preforming good at the shop but when you get home your symptoms return.

If the output transformer is bad and a new one takes a few weeks to arrive, will recording with the amp destroy more than just the already bad output transformer? I'm expecting a "hell ya!" Can I get a "hell ya?"

When something is broke and you continue using it it becomes more broke.
This will cause the price of repair to keep going up and most likely into the "Not worth it anymore" price range.

DO NOT TURN IT ON ANYMORE.

 

[agedhorse]

Is there any audible way to tell if the output transformer is bad?
I see they run about $300 bucks for the Heyboer and $307 for an Ampeg. The Heyboer is USA made. No idea about the Ampeg.
If the output transformer is bad and a new one takes a few weeks to arrive, will recording with the amp destroy more than just the already bad output transformer? I'm expecting a "hell ya!" Can I get a "hell ya?"

There is a "thing" called troubleshooting, it's why QUALIFIED technicians UNDERSTAND how the circuit is supposed to work, and measure voltages, currents and resistances, to see if they agree with how the circuit should measure. There's no guessing involved, no internet wild ass guesses (which are usually wrong, many are pathetically wrong), scratching heads, pondering something that you do not understand. That's also why they charge what they do, to avoid wasting money on your repair.

Notice that I emphasize QUALIFIED, and UNDERSTAND? That's because there are technicians that have no more understanding that you have, from my extensive experience in this industry, these guys are responsible for causing additional damage and wasting customer's money. I see the results fairly often, it reinforces why it's important for a tech to really understand the theory behind how the circuits are supposed to work and with good fault tree analysis skills.

Why in the world would you replace a transformer without confirming through measurement and analysis that it's actually bad, or that there is no additional faults that could jeopardize a new transformer???