Cheap PCB amps are junk!? OK, I'll 'fess up ...

Rob DiStefano · September 26th, 2006, 05:48 PM

... I recently revisited the Epi Valve Jr. by way of MF (hey, I saved on the shipping - that was an incentive of sorts). A few dayze later it arrives, dead as door nail, won't even light up, and it went back on MF's dime. A week or so goes by and another arrives. The pilot light works - a good sign - and she's really quiet (unlike the first VJr. I had). I plug in a fave Tele w/Keystones and I'm totally digging the EL84 tone. Yeah, really. I take it back - PCB or not, these new & cheap VJr's are too good to pass up.

Tremo · September 26th, 2006, 06:10 PM

Maybe they do sound good, that's great. But none the less, the build quality is crap on the cheap PCB amps. You pay your money and take your chances. If they crap out, they're disposable.

maestrovert · September 26th, 2006, 06:10 PM

Quote:

Originally Posted by Rob DiStefano

... I recently revisited the Epi Valve Jr. by way of MF (hey, I saved on the shipping - that was an incentive of sorts). A few dayze later it arrives, dead as door nail, won't even light up, and it went back on MF's dime. A week or so goes by and another arrives. The pilot light works - a good sign - and she's really quiet (unlike the first VJr. I had). I plug in a fave Tele w/Keystones and I'm totally digging the EL84 tone. Yeah, really. I take it back - PCB or not, these new & cheap VJr's are too good to pass up.

uh, you ok there Rob ? sure you don't wanna go lie down or something ?

txspreacher · September 26th, 2006, 06:24 PM

Quote:

Originally Posted by Tremo

Maybe they do sound good, that's great. But none the less, the build quality is crap on the cheap PCB amps. You pay your money and take your chances. If they crap out, they're disposable.

Well, they are disposable. I hear that some good tones can be coaxed out for cheap. But, like you experienced Rob, I've heard of alot of folks (more than not, in fact) that got one that was DOA or the pilot light came on, and that was it. If I was in the market for a quick grab 'n' go, I might consider it.

Rob DiStefano · September 26th, 2006, 06:38 PM

Quote:

Originally Posted by maestrovert

uh, you ok there Rob ? sure you don't wanna go lie down or something ?

I'm actually annoyed that this VJr sounds so danged good. Grrrrr.

Rob DiStefano · September 26th, 2006, 06:55 PM

Quote:

Originally Posted by Tremo

Maybe they do sound good, that's great. But none the less, the build quality is crap on the cheap PCB amps. You pay your money and take your chances. If they crap out, they're disposable.

Yep, for sure. Everything I've always preached about PCB junkers. When (not IF) this one dies it'll become a platform for a complete rebuild ala PTP.

Gee · September 26th, 2006, 06:57 PM

Jesus, here we go again.

You know, the thing about the Epi VJ is that it gives you a cheap ring side seat for an expensive members only show. Those who paid the full show price, and spent the time joining the club, don't like that there is a low cost back door entry into the exclusive show.

Or like Rob, you can go back, spend $100 and listen with an open mind. Good on ya mate.

Don't forget to check out the VJ (1158 reply) thread over at 18Watt.com.

GUITARmole · September 26th, 2006, 08:55 PM

FWIW, there ARE some decent yet cheap PCB amps. IMO the Vox AC15CC is one of them. The build quality is actually decent with the tube sockets mounted on the chassis (and not the PCB) and it sounds great!

11 Gauge · September 26th, 2006, 09:00 PM

The cool thing about amps like this is that you can run them until they crap out, and then fabricate a simple board to get them up and running again, due to the circuit simplicity.

I had a Pignose G40V that was a total rat's nest inside. If it would have gone kaput, I would have built a board for it, and it would have taken me just an afternoon. Even with the PCB, I was able to mod the heck out of it.

I see some amps as toys, and the super cheap PCB tubers fall into this category. I'd never gig with one, but they sure can be fun around the house, or for quiet little jam sessions.

yegbert · September 26th, 2006, 09:35 PM

Rob, thanks for trying it out and sharing frankly.

PraiseCaster · September 26th, 2006, 09:43 PM

I've heard some say really great things about the Magnetix Mod's for the Valve Jr.

I know one guy that gig's all the time, and he even takes his Valve Jr. as a back up at venues where he is piped through the PA. He loves the tone of it that much!

BradKM · September 26th, 2006, 09:48 PM

I've added it to my Christmas list. I'm just thrilled about the multiple speaker outs on the thing. A tiny head that I can use with any speaker cab on hand, for less than a c-note? I'm there.

DrewB · September 26th, 2006, 10:07 PM

Quote:

Originally Posted by Rob DiStefano

... I recently revisited the Epi Valve Jr. by way of MF (hey, I saved on the shipping - that was an incentive of sorts). A few dayze later it arrives, dead as door nail, won't even light up, and it went back on MF's dime. A week or so goes by and another arrives. The pilot light works - a good sign - and she's really quiet (unlike the first VJr. I had). I plug in a fave Tele w/Keystones and I'm totally digging the EL84 tone. Yeah, really. I take it back - PCB or not, these new & cheap VJr's are too good to pass up.

I'm proud of ya! For an amp that is, admittedly, not the best built, that little booger sounds awfully good. As others have said, a complete rebuild wouldn't be a lot of trouble, and it might even wind up sounding better. If mine bites it at some point, that's what I'll do, probably using terminal strips so I can install chassis-mounted tube sockets. Yeah, it sounds that good!

JohnnyCrash · September 26th, 2006, 11:53 PM

I've had tons of PCB amps, and they all sounded pretty good, bar one or two of course :)

IDK how many DOA stories I've heard about this one single amp, though, but it's been WAY too many. It is really a sad commentary on it's quality.

I have no prejudice based on it's price (or poor quality for that matter) - I just don't like them - soundwise. Then again, I personally HATE the Blues and Pro Junior amps as well and those are well liked by MANY many people on this forum.

On the other hand I've heard many folks frustrated at the "poor tone" they got from a Champ!

I guess tatse will always be a funny thing ;)

But it is funny how the "snob" factor is always brought up... like somebody is really miffed at good tone for dirt cheap prices! If I liked it, I would've viewed the $100 as money very well spent :)

Congrats on finding another amp you like Rob!

tdu · September 27th, 2006, 06:38 AM

I was pretty impressed with the tone of the VJ when I tried it in the store. And I thought cosmetically, it was a really cool design. If they made a 10-15 watt version of it I likely would have bought it because that's what I was shopping for at the time. I know there is the Standard, but I like the simple control layout of the Jr.. And I know you don't have to use them, but I hate the fact that the DSP effects are even on the Standard.

Rob DiStefano · September 27th, 2006, 07:53 AM

Quote:

Originally Posted by JohnnyCrash

... But it is funny how the "snob" factor is always brought up... like somebody is really miffed at good tone for dirt cheap prices! If I liked it, I would've viewed the $100 as money very well spent :)

Congrats on finding another amp you like Rob!

Everything about music is subjective, surely including the gear. What's annoying about a VJr is that maybe one outta X number of these turkeys actually works and sounds darned nice (to me).

How long it will continue to work is the crap shoot, and THAT is the really annoying part - I don't think it's trustworthy for anything but casual use, and that's a shame 'cause I'd really like to gig with it.

Heck, I'm already gathering parts for a rebuild - and building a 2x12 cab for it.

TC7 · September 27th, 2006, 10:16 AM

Quote:

Originally Posted by Rob DiStefano

Heck, I'm already gathering parts for a rebuild

Well, if it is just a matter of time before they fail... and if you discover a PTP scheme that works for you... and if you want to pass it along...

I'd love more info about that PTP plan. I modded my EVJrH... but now that that project is done, I'm ready for another project.

By the way, it's very cool you gave the VJr another listen!

Rob DiStefano · September 27th, 2006, 10:24 AM

Quote:

Originally Posted by TC7

Well, if it is just a matter of time before they fail... and if you discover a PTP scheme that works for you... and if you want to pass it along...

I'd love more info about that PTP plan. I modded my EVJrH... but now that that project is done, I'm ready for another project.

By the way, it's very cool you gave the VJr another listen!

A 5F1 6V6 platform is simple enuf to fabricate - https://taweber.powweb.com/store/5f1_layout.jpg

I do like that single EL84 tone though, so maybe this - https://taweber.powweb.com/store/smokeI_layout.jpg

Gee · September 27th, 2006, 12:00 PM

Quote:

Originally Posted by Rob DiStefano

I do like that single EL84 tone though, so maybe this - https://taweber.powweb.com/store/smokeI_layout.jpg

If you make the resistor and cap changes to the VJ that are outlined on 18Watt.com, add an MV and a Princeton tone control, you end up with an exact Smokin Joe for about half the cost of the Smokin Joe.

Keifer · September 27th, 2006, 12:37 PM

A couple months ago I picked up a 16 watt Crate Palomino cheap at a yard sale. When this little box fails, it's destined for the bench and within a couple days it'll be rewired point-to-point.

Mwieczorek · September 27th, 2006, 12:39 PM

I've got my Valve Jr. head driving a homebrew 2x12 cab packed with a pair of Eminence Texas Heats. It sounds GREAT cranked up. But, it's actually too loud to crank in the living room, so I'm going to build a single 8" cab and put a less efficient speaker in it.

Have fun with it!

Mwieczorek

kludge · September 27th, 2006, 01:19 PM

A while back, I went looking for a good Champ-style amp for home recording and practice. I tried a bunch of nice vintage amps at Willie's, including several tweed Champs and Princetons, silverface Champs, Gibson Skylarks, and a couple of small lap steel amps.

The best of the bunch by far was a Gibson GA5, which had a GREAT growly voice. The only other really great ones were a couple of blackface Princeton Reverbs that were too loud for my purposes. The rest ran the gamut from just okay to downright bad, and honestly, most of them were bad.

I wound up getting a Valve Junior. It's a better-sounding amp than 80% of the vintage equivalents I tried, and in better condition than ANY of them. Sure, there were a few that beat it soundly, but for how long before they need a cap job or blow a transformer?

Rob DiStefano · September 28th, 2006, 07:50 AM

The 18watt.com board has that huge, still growing VJr thread that's just chock fulla good, or at least interesting, stuff to consider.

In answer to my query there, the minimalist mod for insuring a long VJrH (head) life without any significant tone altering was offered by one amp guru as changing R10 to 1K5W, R14 to 240, and adding a 1K1W resistor off pin 9 of the EL84. I trust this guy, I'm gonna do those mods.

There are other significant "Deluxe SILVER Plated" circuit changes that folks have done to "better" the tone ...

R1 1meg (1/2w on all resistors unless noted)
R2 10K
R6 shorted out
R7 91k, or replaced with 500K or 250k pot, for Gain control
R8 1k or 1.5k (the exact value doesn't matter too much)
R9 620 ohms
R14 240 ohms (the "life" mod)
R10 1K 3W (the "life" mod)
C3,C4 3.3uf 6v (or anything between 2uF to 4.7uF to your taste)
C5 1000uf 16v

I'm totally NOT an amp person, so take all of what I typed above with perhaps some reservation. I like my VJrH's tone as is, so I dunno if I wanna go further than the "life" mods and changing tubes.

The "Deluxe GOLD Plated" version of the above mods would also include changing the OT to something like a Hammond 125DSE - folks who've done this say it makes a noticeable difference.

So, I'll probably just try to keep the amp alive as is and not do a rebuild. Maybe. Sorta.

The mods ...

Gee · September 28th, 2006, 09:41 AM

Rob - the schematic you show is for the very first version of the VJ, i.e. the one that was noisey.

However, the mods you list from the 18Watt are a good summary of the current evolution of those mods and the component identification can be read from the VJ PCB. The OT is well worth changing as the stanard one is a small Champ sized one.

Rob DiStefano · September 28th, 2006, 09:57 AM

Quote:

Originally Posted by Gee

Rob - the schematic you show is for the very first version of the VJ, i.e. the one that was noisey.

Yeah, my bad, wrong pic - I just replaced it with the head version that has the DC filaments added.

However, the mods you list from the 18Watt are a good summary of the current evolution of those mods and the component identification can be read from the VJ PCB. The OT is well worth changing as the stanard one is a small Champ sized one.

Some folks think the Champ sized OT is worth saving for the "vintage" tone. Dunno about that.

September 26th, 2006, 05:48 PM	#1 (permalink)
Rob DiStefano Friend of Leo's Join Date: Mar 2003 Location: Park Ridge, NJ Age: 62 Posts: 4,788	Cheap PCB amps are junk!? OK, I'll 'fess up ... ... I recently revisited the Epi Valve Jr. by way of MF (hey, I saved on the shipping - that was an incentive of sorts). A few dayze later it arrives, dead as door nail, won't even light up, and it went back on MF's dime. A week or so goes by and another arrives. The pilot light works - a good sign - and she's really quiet (unlike the first VJr. I had). I plug in a fave Tele w/Keystones and I'm totally digging the EL84 tone. Yeah, really. I take it back - PCB or not, these new & cheap VJr's are too good to pass up.

September 26th, 2006, 09:00 PM	#9 (permalink)
11 Gauge Friend of Leo's Join Date: Mar 2003 Location: The East Coast Posts: 3,015 10 Photos	The cool thing about amps like this is that you can run them until they crap out, and then fabricate a simple board to get them up and running again, due to the circuit simplicity. I had a Pignose G40V that was a total rat's nest inside. If it would have gone kaput, I would have built a board for it, and it would have taken me just an afternoon. Even with the PCB, I was able to mod the heck out of it. I see some amps as toys, and the super cheap PCB tubers fall into this category. I'd never gig with one, but they sure can be fun around the house, or for quiet little jam sessions. __________________

September 26th, 2006, 09:43 PM	#11 (permalink)
PraiseCaster Friend of Leo's Join Date: Mar 2003 Location: Whittier, California Posts: 4,347 16 Photos	I've heard some say really great things about the Magnetix Mod's for the Valve Jr. I know one guy that gig's all the time, and he even takes his Valve Jr. as a back up at venues where he is piped through the PA. He loves the tone of it that much! __________________ Later! PraiseCaster Visit Guitarists Praise and Worship Forum!! Dance Like David, MySpace

September 26th, 2006, 09:48 PM	#12 (permalink)
BradKM Tele-Meister Join Date: Apr 2003 Location: Charlotte, NC Posts: 420	I've added it to my Christmas list. I'm just thrilled about the multiple speaker outs on the thing. A tiny head that I can use with any speaker cab on hand, for less than a c-note? I'm there. __________________ "Go Team Venture!"

September 27th, 2006, 06:38 AM	#15 (permalink)
tdu Friend of Leo's Join Date: Jan 2005 Location: Ontario, Canada Age: 32 Posts: 2,452 11 Photos	I was pretty impressed with the tone of the VJ when I tried it in the store. And I thought cosmetically, it was a really cool design. If they made a 10-15 watt version of it I likely would have bought it because that's what I was shopping for at the time. I know there is the Standard, but I like the simple control layout of the Jr.. And I know you don't have to use them, but I hate the fact that the DSP effects are even on the Standard. __________________ Torn Down Units brand Rock n' Roll My Solo Stuff:

September 26th, 2006, 06:10 PM	#2 (permalink)
Tremo Friend of Leo's Join Date: Mar 2003 Location: Silicon Valley, CA, USA Posts: 3,767	Maybe they do sound good, that's great. But none the less, the build quality is crap on the cheap PCB amps. You pay your money and take your chances. If they crap out, they're disposable.

September 26th, 2006, 06:57 PM	#7 (permalink)
Gee Tele-Meister Join Date: Mar 2006 Location: Wales Posts: 307	Jesus, here we go again. You know, the thing about the Epi VJ is that it gives you a cheap ring side seat for an expensive members only show. Those who paid the full show price, and spent the time joining the club, don't like that there is a low cost back door entry into the exclusive show. Or like Rob, you can go back, spend $100 and listen with an open mind. Good on ya mate. Don't forget to check out the VJ (1158 reply) thread over at 18Watt.com.

September 26th, 2006, 08:55 PM	#8 (permalink)
GUITARmole Tele-Afflicted Join Date: Mar 2005 Location: Portland, OR Posts: 1,117 50 Photos	FWIW, there ARE some decent yet cheap PCB amps. IMO the Vox AC15CC is one of them. The build quality is actually decent with the tube sockets mounted on the chassis (and not the PCB) and it sounds great!

September 26th, 2006, 09:35 PM	#10 (permalink)
yegbert Friend of Leo's Join Date: Sep 2004 Location: Clinton, Maryland (US) Age: 54 Posts: 4,850 85 Photos	Rob, thanks for trying it out and sharing frankly.

September 26th, 2006, 11:53 PM	#14 (permalink)
JohnnyCrash Poster Extraordinaire Join Date: Mar 2005 Location: Lost Angeles and Orange County Posts: 7,128	I've had tons of PCB amps, and they all sounded pretty good, bar one or two of course :) IDK how many DOA stories I've heard about this one single amp, though, but it's been WAY too many. It is really a sad commentary on it's quality. I have no prejudice based on it's price (or poor quality for that matter) - I just don't like them - soundwise. Then again, I personally HATE the Blues and Pro Junior amps as well and those are well liked by MANY many people on this forum. On the other hand I've heard many folks frustrated at the "poor tone" they got from a Champ! I guess tatse will always be a funny thing ;) But it is funny how the "snob" factor is always brought up... like somebody is really miffed at good tone for dirt cheap prices! If I liked it, I would've viewed the $100 as money very well spent :) Congrats on finding another amp you like Rob!

September 27th, 2006, 12:37 PM	#20 (permalink)
Keifer Tele-Holic Join Date: Dec 2003 Location: Louisville, KY Posts: 565	A couple months ago I picked up a 16 watt Crate Palomino cheap at a yard sale. When this little box fails, it's destined for the bench and within a couple days it'll be rewired point-to-point. __________________ Electric:Teles, Strats, pedal steel Acoustic:dobro, 5-string banjo, mandolin

September 27th, 2006, 12:39 PM	#21 (permalink)
Mwieczorek TDPRI Member Join Date: Dec 2004 Location: Norwalk, Ohio Age: 29 Posts: 87	I've got my Valve Jr. head driving a homebrew 2x12 cab packed with a pair of Eminence Texas Heats. It sounds GREAT cranked up. But, it's actually too loud to crank in the living room, so I'm going to build a single 8" cab and put a less efficient speaker in it. Have fun with it! Mwieczorek __________________ I are an engineer... I know that E=mc^2 and you can't push a rope.

September 27th, 2006, 01:19 PM	#22 (permalink)
kludge Tele-Afflicted Join Date: Aug 2006 Location: Minneapolis Age: 43 Posts: 1,025	A while back, I went looking for a good Champ-style amp for home recording and practice. I tried a bunch of nice vintage amps at Willie's, including several tweed Champs and Princetons, silverface Champs, Gibson Skylarks, and a couple of small lap steel amps. The best of the bunch by far was a Gibson GA5, which had a GREAT growly voice. The only other really great ones were a couple of blackface Princeton Reverbs that were too loud for my purposes. The rest ran the gamut from just okay to downright bad, and honestly, most of them were bad. I wound up getting a Valve Junior. It's a better-sounding amp than 80% of the vintage equivalents I tried, and in better condition than ANY of them. Sure, there were a few that beat it soundly, but for how long before they need a cap job or blow a transformer?

September 28th, 2006, 07:50 AM	#23 (permalink)
Rob DiStefano Friend of Leo's Join Date: Mar 2003 Location: Park Ridge, NJ Age: 62 Posts: 4,788	The 18watt.com board has that huge, still growing VJr thread that's just chock fulla good, or at least interesting, stuff to consider. In answer to my query there, the minimalist mod for insuring a long VJrH (head) life without any significant tone altering was offered by one amp guru as changing R10 to 1K5W, R14 to 240, and adding a 1K1W resistor off pin 9 of the EL84. I trust this guy, I'm gonna do those mods. There are other significant "Deluxe SILVER Plated" circuit changes that folks have done to "better" the tone ... R1 1meg (1/2w on all resistors unless noted) R2 10K R6 shorted out R7 91k, or replaced with 500K or 250k pot, for Gain control R8 1k or 1.5k (the exact value doesn't matter too much) R9 620 ohms R14 240 ohms (the "life" mod) R10 1K 3W (the "life" mod) C3,C4 3.3uf 6v (or anything between 2uF to 4.7uF to your taste) C5 1000uf 16v I'm totally NOT an amp person, so take all of what I typed above with perhaps some reservation. I like my VJrH's tone as is, so I dunno if I wanna go further than the "life" mods and changing tubes. The "Deluxe GOLD Plated" version of the above mods would also include changing the OT to something like a Hammond 125DSE - folks who've done this say it makes a noticeable difference. So, I'll probably just try to keep the amp alive as is and not do a rebuild. Maybe. Sorta. The mods ... Last edited by Rob DiStefano; September 29th, 2006 at 05:34 AM.

September 28th, 2006, 09:41 AM	#24 (permalink)
Gee Tele-Meister Join Date: Mar 2006 Location: Wales Posts: 307	Rob - the schematic you show is for the very first version of the VJ, i.e. the one that was noisey. However, the mods you list from the 18Watt are a good summary of the current evolution of those mods and the component identification can be read from the VJ PCB. The OT is well worth changing as the stanard one is a small Champ sized one.