Power Amp Help -- VHT2502 Owners

[JLagoon]

Hi all,

I may have a problem with the VHT2502. The volume, presence and depth controls for channel A doesn't work at all. :smack: :smack:

Here's how I wired it:

Units:
1 Delay unit (Boss DE 200)
1 VHT 2502
1 4x12 cabinet (set to stereo operation)

Delay Unit MIX (TRS cable)--> VHT Chan. A --> Cabinet L
Delay Unit Invert MIX (TRS cable)--> VHT Chan. B --> Cabinet R

When I use this wiring, only the controls for channel B work. The sound that comes from the RIGHT side (invert mix) is lower than the LEFT side.

When I only use the channel A (leaving channel B unplugged), the controls that work are still channel B controls. And when I put channel B in standy (only powering channel A), I hear my playing, but it's crackled and very low in volume.

I'm pretty sure that it wasn't like this before; meaning that I could operate both channels independently.

Is this a case of a bad tube? I retubed both channels back in late February with 4 JJ EL34L and have used them for approximately 80 hours.

Thanks!

 

[Duke of Metal]

Re: Power Amp Help -- VHT2502 Owners

You know.. i has a similar thing going on but it turned out I plugged my speaker cable into the wrong output.

For some reason, the 2502's outputs are positioned opposite to their inputs. (picture attached)

Try switching the speaker cable around the different outputs to see if it produces any sound.

Basicly go:
Guitar --> Triaxis --> VHT 2502 --> cabinet

Plug your Triaxis into Channel A input of the VHT 2502 and turn the volume at around 9 o'clock or so (just loud enough to hear your playing through the speakers). Plug it into Channel A output (bottom 2 on right side) and see if it makes any sound thats affected by channel A controls.

Before you do that, unplug any cable from Channel B input and Channel B outputs. that way, your only working with Channel A.

Give that a try and see if it helps.


Cheers

 

[JLagoon]

Re: Power Amp Help -- VHT2502 Owners

Hey Duke!

Thanks for the reply, man. Apparently, this is a case of a blown fuse. When I turned on the standby button, there was no electrical "jump start" sound. I checked the fuse of channel A, and yes, it was blown. I replaced the fuses for both channels. Now it works well.

I just noticed the way the output jacks are positioned today. I was wondering why channel A came out of the right side (should be LEFT) and channel B came out of the opposite side. Now that you report and illustrate the same thing, that explains it.

By the way, have you tried using 6L6 on one side and EL34 on the other?

Thanks again!!!

:dance: :dance: :dance:

 

[Duke of Metal]

Re: Power Amp Help -- VHT2502 Owners

Hey Duke!

Thanks for the reply, man. Apparently, this is a case of a blown fuse. When I turned on the standby button, there was no electrical "jump start" sound. I checked the fuse of channel A, and yes, it was blown. I replaced the fuses for both channels. Now it works well.

I just noticed the way the output jacks are positioned today. I was wondering why channel A came out of the right side (should be LEFT) and channel B came out of the opposite side. Now that you report and illustrate the same thing, that explains it.

By the way, have you tried using 6L6 on one side and EL34 on the other?

Thanks again!!!

:dance: :dance: :dance:

Ahhh.. damn those fuses.. but hey, they do save the amp at the end..

Actully.. a whole bunch of people have tried 6L6s in the 2502 and all of them have said they worked fine in there, but the bias range is not high enough to accept 6L6s, so they'll be biased cold and they wont sound that great.

If you want something with tighter, thicker and punchier lowned and overall tone. Try the JJ E34Ls or even the new JJ KT77s. The JJ KT77s are suppose to be a very hot rodded sounding EL34. I have a quad of them here with me, but I cant plug them in until my VHT 412 fatbottom slant cabinet arrives..

regarding the outputs.. yes. that fooled me the first time I got the poweramp. I thought it was a defective unit but I tried the other outputs and it worked just fine. When I opened up the top panel of the unit and looked at the wiring of the jack, thats the way they're wired from the factory as it seemed.


Cheers

 

[JLagoon]

Re: Power Amp Help -- VHT2502 Owners

Wait, I can swap EL34 with KT77 with the same bias???

I'm using matched quad JJ EL34L now. I thought EL34L is the end of EL34. I wonder if the KT77 is a good match with the TriAxis. Let us know how it sounds with your setup. :fing2:

 

[Duke of Metal]

Re: Power Amp Help -- VHT2502 Owners

Wait, I can swap EL34 with KT77 with the same bias???

I'm using matched quad JJ EL34L now. I thought EL34L is the end of EL34. I wonder if the KT77 is a good match with the TriAxis. Let us know how it sounds with your setup. :fing2:

The brand new currently made JJ KT77s are direct replacement for EL34s.

I will let you know how they sound compared to standard EL34s. But it probebly wont be for another week or more.

either way, I'll let you know.

What cabinet are you using with your rig?


Cheers

 

[JLagoon]

Re: Power Amp Help -- VHT2502 Owners

Thanks!

I use Behringer BG412S cabinet. I like the angled top speakers design, I figured that I could just replace the speakers, which are already good, when necessary in the future and still benefit from the structural construction of the cabinet. Maybe I'll get another one.

 

[Duke of Metal]

Re: Power Amp Help -- VHT2502 Owners

Thanks!

I use Behringer BG412S cabinet. I like the angled top speakers design, I figured that I could just replace the speakers, which are already good, when necessary in the future and still benefit from the structural construction of the cabinet. Maybe I'll get another one.

I tried one of those cabinets.. they do the job.

I personally so far like Marshall cabients. the 1960A and 1960B. I still kick my self sometimes trading my old school Marshall JCM800 straight 412 cabinet for a Mesa Traditional 412 cabinet.

I hated the mesa soo much tone wise.. that I sold it not even 4 days after getting it. I put the money toward a VHT 412 Slant Fatbottom cabinet, which I am still waiting for. VHT (the company) is taking their freaking time with the thing... and if I dont like that one either, then I am going back to the old school Marshall cabinets and do some of the mods to them like I did to my old JCM 800 cab. replace the wiring & re-enforce the back panel. Possibly even add some dacron polyester. that made the cabinet tighter and more punchy, specially at high volumes.

Anyways.. I'll let you know about the tubes when I get a chance to plug them in.


Cheers