RGV40 - clone of VALVE SPECIAL?

[Kich]

Hi everyone! I have an amplifier. Invasion RGV40.

 

http://img641.imageshack.us/i/img6509.jpg/

 

http://img682.imageshack.us/i/img6510d.jpg/

 

This amplifier is not different from the outside Epifone valve special. Internals are very similar as well.

 

http://img401.imageshack.us/i/img6512e.jpg/

 

http://img690.imageshack.us/i/img6513q.jpg/

 

http://img199.imageshack.us/i/img6514q.jpg/

 

http://img52.imageshack.us/i/img6515.jpg/

 

 

A set of parts is the same. At the internals is marking Epifone.

Amplifier assembled in the three lamps as Epifone valve special.

He also has a block of DSP. I need to work around it! But the roads on the board are different from Epifone valve specialists. Although it is possible scheme is no difference. Help to identify these photos where you want to do circumambulation DSP please! And if there are other ideas for modifications - contact guys!

 

View of the fee from the details:

 

http://img99.imageshack.us/i/img6552o.jpg/

 

View of the fee from the tracks:

 

http://img89.imageshack.us/i/img6550.jpg/

 

Combined: track and parts. View of the fee from the details:

 

http://img367.imageshack.us/i/img6550.jpg/

 

Can you find differences in the scheme with Epifone Valve special? Thanks to all who can help and point where I need to make a bridge over the CPD. As well as other modifications!

[Kich]

UPS...!

[Kich]

I see no body who can give answer fore me there. Here is not realy professionals. All people just bla-bla-bla.

I am disappointed.

[carverman]

I see no body who can give answer fore me there. Here is not realy professionals. All people just bla-bla-bla.

I am disappointed.

 

Vat you vant in questions? Ve are professionals but sometimes we blah-blah-blah. Very nice PC board vith

lamps (we call tubes here) und components. Is copy of Epiphone amp Yes?/No.

 

Ve try to help but pictures not enough comrade Kich. Ve need more specific questions.

 

 

Ok...

Now ve hav question for you. Is MOSCOW CHICKS REALLY VUNDERBAR? :D

 

(in Rossiya, a long time ago ...is song by Boneyem (Rasputin)

 

"But to Moscow chicks he was such a lovely dear

He could preach the bible like a preacher

Full of ecstacy and fire

But he also was the kind of teacher

Women would desire

 

RA RA RASPUTIN

Lover of the Russian queen

There was a cat that really was gone

RA RA RASPUTIN

Russia's greatest love machine

It was a shame how he carried on

"

[Kich]

I did not want to offend anyone.

 

I have the tubes power amplifier outside not different from the EPIPHONE Valve Special and the inside is very similar. Parts inside the same. The board has marks Valve Special HB01573 VER050728 and the output transformer is marked Valve Junior. That in itself is very interesting, I think. This seems to produce EPIPHONE by an unknown label Invasion. How can this be??!

That's interesting...

 

I basically want to make a bypass DSP. And ask about this.

 

Now about your question ... I'm not very well understood the question. But ... In Russia there was a historical figure Grigori Rasputin. It was a strange figure. Not everything that is in songs is truth.

Russia - a very beautiful and great country. The climate of the subtropical and temperate like west Europe, to north. People are basically good, peace and quiet. The girls mostly - beautiful. :-)

[carverman]

I did not want to offend anyone.

 

I have the tubes power amplifier outside not different from the EPIPHONE Valve Special and the inside is very similar. Parts inside the same. The board has marks Valve Special HB01573 VER050728 and the output transformer is marked Valve Junior. That in itself is very interesting' date=' I think. This seems to produce [b']EPIPHONE[/b] by an unknown label Invasion. How can this be??!

That's interesting...

 

This being a clone, is most likely made in China. Anybody with electronic smarts

can reverse engineer a circuit board by removing the components, then using

printed circuit camera technology, make a new photo resist mask for etching the

circuit board and a component layout mask. By doing this, the pc layout and

any board indentification markings are also copied and who ever did this

did not bother to erase the markings off the photo mask when they made these

boards, I expect. This is similar to the many fake guitars now being sold directly

from Chinese exports that carry the Epiphone name, but not made at the

authorized Epiphone Chinese or Asian Epiphone factories.

 

I would venture guess that "Invasion" is a name that this manufacturer or marketer uses.

 

I basically want to make a bypass DSP. And ask about this.

Well, you are not specific about what kind of DSP you want to make, and any

DSP is very complicated with a unique set of microchips...A/D -> DSP (with it's own

parameter/program external controls) -> D/A. Generally speaking, these are a compact

LSI 3 chip set with external components, such as a crystal (12.288 mhz), capacitors

and interface (i/p and o/p) drivers.

 

Here is a schemo of what I am talking about..

http://www.wavefrontsemi.com/UserFiles/File/AL_Info/AL32/Wavefront%20EV3201A%20Eval%20Board%20Data%20Sheet.pdf

 

 

Now about your question ... I'm not very well understood the question. But ... In Russia there was a historical figure Grigori Rasputin. It was a strange figure. Not everything that is in songs is truth.

Russia - a very beautiful and great country. The climate of the subtropical and temperate like west Europe, to north. People are basically good, peace and quiet. The girls mostly - beautiful. :-)

 

Sorry, I made a hearty joke because you mention you are from Russia. Yes, it

was a song made popular years ago and somehow it seemed to be funny.

My parents come from Ukraine, and I can understand/speak a bit of Russian.

[brianh]

Well' date=' you are not specific about what kind of DSP you want to make, and any

DSP is very complicated with a unique set of microchips...A/D -> DSP (with it's own

parameter/program external controls) -> D/A. Generally speaking, these are a compact

LSI 3 chip set with external components, such as a crystal (12.288 mhz), capacitors

and interface (i/p and o/p) drivers.

 

Here is a schemo of what I am talking about..

http://www.wavefrontsemi.com/UserFiles/File/AL_Info/AL32/Wavefront%20EV3201A%20Eval%20Board%20Data%20Sheet.pdf

[/quote']

Carver, I think the comrade was asking how to completely bypass the DSP on a Valve Special. I have a VS and that DSP is awful, I'd like to know how to do it too, and I haven't seen anything on it at sewatt.

 

BTW, is it not possible that these Invasions are just Epi amps rebadged for the Russian market? Not sure why anyone would go to the troube to reverse engineer a $200 combo to sell in Russia, when they could easily rip off Fender, Ampeg, Marshall, etc. with equal impunity.

[carverman]

Carver' date=' I think the comrade was asking how to completely bypass the DSP on a Valve Special. I have a VS and that DSP is awful, I'd like to know how to do it too, and I haven't seen anything on it at sewatt. [/quote']

 

Ok, that makes more sense...I misunderstood the "make a bypass DSP" in his own words, and thought he

was trying to get some info on how to make a DSP..which requires those mini beam lead LSI chips and they

cannot be soldered by hand..at least reliably, and he would be better off getting a commerically available

board and interfacing it with the amp.

 

As far as bypassing the dsp, in a tube amp..it should be possible..I haven't looked at

the schemo for this particular amp, but all you would need is a jumper at some point

in the actual circuit. My Alesis DSP has a rotary 16 position encoder switch at the

front panel with a Bypass position..but I'm surprised that there is no bypass on yours

or his.

 

Point me to the schematic and I will try and figure it out.

 

BTW, is it not possible that these Invasions are just Epi amps rebadged for the Russian market? Not sure why anyone would go to the troube to reverse engineer a $200 combo to sell in Russia, when they could easily rip off Fender, Ampeg, Marshall, etc. with equal impunity.

 

Well it could be..but why would Epiphone do that? Is there some political reason why Epi could not sell

their amps badged as Epiphones in the Russian market..I mean these are not fighter aircraft or space

shuttle components that need State Dept approval first.

 

Yes, you may be right. The Russian market is probably huge now with the new generation of musicians,

so it is possible that the amp was rebadged for some purpose..and over the years Epiphone guitar designs

and models have been sold under several brand names..although I'm sure their musicians would

not be happy about Gibson guitars being rebadged.

 

I was just trying to make a point that someone could easily rip off the pc design by disassembly of the

finished pc board and making their own copies of it..after all most of the tubes made these days

are made in Russia (Sovtek) and some of their former republics (ElectroHarmonix), so maybe there

was some other reason?

[brianh]

Here's a link to a previous thread with multiple links to the VSp schematics: http://forums.epiphone.com/default.aspx?g=posts&t=5335

 

Pickpicker posted some instruction and photos that look like they'll work. But it seems that the outcome was inconclusive or the original poster gave up though. It would be good to have your opinion on this before I rip it apart.

 

Thanks, Brian

[carverman]

Here's a link to a previous thread with multiple links to the VSp schematics: http://forums.epiphone.com/default.aspx?g=posts&t=5335

 

Pickpicker posted some instruction and photos that look like they'll work. But it seems that the outcome was inconclusive or the original poster gave up though. It would be good to have your opinion on this before I rip it apart.

 

Thanks' date=' Brian[/quote']

 

 

The DSP appears to be fairly simple as far as the external leads, but it's hard to

tell what kind it is.

Looks like pins 15, 14.13.11 and 10 go to a separate isolated pc gnd, which is

not the same as the tube ground...and the grounds (cathodes) of the tubes and

the +5v +12 and -12 are separate from the tube power supply ground as the

tube ground signal is different. The +12 and -12v are used for the op amps.

 

Pin 9, 7, 5, 3 are the prgm inputs.

pin 12 and 6 are inputs 1 and 2.

 

Pin 8 is + 5 v regulated to the DSP chip.

 

Pin 4 goes to TR1 which appears to be some kind of electronic switch.

 

Pin 2 is the o/p of the DSP and goes to a 50K volume or DSP level adjustment.

 

It is possible that there might be a bypass value on the prgm pin o/p but

with some detail on the possible 16 values , it is difficult to say. Most DSP

will be designed (at least I would think) with a bypass inside the program

by with values from 0 to 15 (or 1-16) you would need to consult the chip

info.

 

I would think that to disable the DSP, you would need to lift the o/p lead that

goes to one side of VR5 (DSP 50K). This will disconnect the volume control

from the o/p of the DSP...This would be my first attempt at a permanent bypass.

 

The other way is to disable both inputs to the DSP.

[Andyroid]

Hi, regarding the different brand name, there are lot's of em! All made in the same factory. I have a Grainger Blues Twin 30. It says Epiphone BC30 inside and there are a couple of extra screw holes under the Grainger badge, I suspect an Epiphone badge would fit there nicely! What is interesting is these rebranded amps sell at a fraction of the price. Here in England an Epiphone BC30 weighs in at £450, a Grainger BC30 costs a mere £200. Same amp, more middle men making profit, smaller price tag! Cheeky Epiphone extortionists!

[carverman]

Hi' date=' regarding the different brand name, there are lot's of em! All made in the same factory. I have a Grainger Blues Twin 30. It says Epiphone BC30 inside and there are a couple of extra screw holes under the Grainger badge, I suspect an Epiphone badge would fit there nicely! What is interesting is these rebranded amps sell at a fraction of the price. Here in England an Epiphone BC30 weighs in at £450, a Grainger BC30 costs a mere £200. Same amp, more middle men making profit, smaller price tag! Cheeky Epiphone extortionists![/quote']

 

Well, I guess everyone needs to make a buck these days, so Epiphone (factory) is

now doing what the car makers have been doing for years..rebadging based on

the market area likes.

 

I remember there was one car whose model name sounded good in the NA market,

but came out something like "bad car" when translated to another language, so

the same car was rebadged for that market..I can't remember the make.

The Russian made Lada was similar...cheap to buy..but not last long.

[Andyroid]

I think you're talking about the MR2, which in French means "The Car is Sh*t". Still, I'm happy about the situation, in a couple of weeks I'm buying a second hand Grainger BC30 for £150. Bargain! :-)

[RSDx]

I remember there was one car whose model name sounded good in the NA market' date='

but came out something like "bad car" when translated to another language, so

the same car was rebadged for that market..I can't remember the make.

[/quote'] I believe you might be referring to the Chevy Nova in the Spanish speaking countries ..... Nova (more specifically "no va") translated into Spanish roughly equates to "it does not go" or "does not go" or something like that.... guess they had to rename them...heh

[carverman]

I believe you might be referring to the Chevy Nova in the Spanish speaking countries ..... Nova (more specifically "no va") translated into Spanish roughly equates to "it does not go" or "does not go" or something like that.... guess they had to rename them...heh

 

Yes, that is the one.

there were others, but that one comes to mind..

 

here is a link to some other interesting english phrase translations that sounded weird

in other languages..especially Spanish..

and that Mitsubishi model must have raised a few chuckles before it was renamed..

http://spanish.about.com/cs/culture/a/chevy_nova_2.htm

[Kich]

Hi guys! Sorry for my long silence! I was very busy.

I did my "homework". I painted scheme on my board. The scheme which I painted is absolutely identical to the valve Special latest models!

 

A good professional Chris Gordon told me to it and showed how to do bypass DSP.

 

http://img689.imageshack.us/img689/6282/mod1c.jpg

 

I did it. My amp has a good sound now. However, not enough highs. And has the background noise...

Also has a weak effect of the limiter. With good attack. High surge in volume and a slight decrease immediately after. What could it be?