Hello,
After many mods, I would like to put a reverb tank into a Squier 15. I have installed a 12" speaker, offset the clipping diodes, and reduced the size of one of the resistors in the front end of the amp.
So far it has worked out well. I would like to take it further and add a reverb tank as I think it would more depth and texture to the sound. I would appreciate any suggestions, and or input regarding this project.
I already know this is a cheap amp, not worthy of any serious time or effort however, the modifications so far have led to amazing results.
Thank you for any replies or suggestions you may have.
Here is an explanation of what all the number codes mean on the tanks, and a few solid state circuit examples, like the Fender Blues Junior reverb circuit.
Hello,
Thank you g1, I have bookmarked that exact article. I am not competent enough to know where to put it in the Squier 15.
I can salvage a tank out of a crate amp that I have. I am just at a loss as to how to control the intensity and volume.
That is because you have no drive and return circuits. There is a lot more to reverb than just a reverb pan.
Here is a schematic for the Peavey Blazer and Rage amps. The only difference is the Blazer has the reverb. See the dotted line around the enter part of the schematic? That stuff is only in the Blazer. Scroll down to the parts layouts, see the extra parts in the Blazer? You would need those things.
http://bmamps.com/Schematics/Peavey/Peavey_Blazer,_Rage_(4-95)_Schematic.pdf
For such a small Amplifier it's hardly worth it,, better you spend money on a decent Reveb pedal which can be used into other gear down the track.
Phil.
MAYBE the Squier PCB already includes a Reverb circuit, just with no parts in it.
Many manufacturers (including Peavey mentioned above) design a single PCB for both models, for cost and practicity reasons, and either fill it up or not.
Check whether you have unused holes and tracks, enough for 1 TL072 and some 8 or 10 extra capacitors and resistors.
Tracks should lead to a couple 2 pin connectors.
IF so, you may add the needed parts plus a tank, probably the same as in the Crate.
If not, you should check how others do it and kludge a small board, maybe even on perfboard to avoid etching.
Hello,
If I build this reverb circuit from the 15r,and, order the appropriate reverb tank. Where would I insert it into the Squier 15 circuit?
I know everyone thinks this is a waste of time but the reason I really like this amp is because of the controls. It has treble, middle, and bass. Most amps get ice picky or muddy. I also like the fact that with very few mods, it has become quiet playable, moderately loud, without sounding junky.
Sorry chum,,,Two very different circuits so NO you can't just drop in the reverb as shown in the 15R schematic.
Yes you can insert reverb but that will require a fair bit of tweaking to make it work. :-X
As can be seen by looking at both schematics the early squire 15 is a very different circuit to the later model.
Yes the early squire 15 is likely the better sounding circuit but does not have reverb.
BTW I've read that some of the squire's have a tiny transformer and you may struggle to get enough power to drive the extra circuitry,, that might be the later models?
My advice is leave it,, go build the same circuit but add the reverb.
Plenty of good ideas on how to accomplish that at ESP.
http://sound.whsites.net/project34.htm
Phil.
Just curious, *WHICH* of two Squier15 amps do you have?
IF you have the "non R" version of the bottom one, your PCB willbe the same as the reverb version but with the components inside the dotted rectangle not fitted, what Enzo and I told you earlier.
IF so, you cn fit missing parts and it might match the Crate tank.
IF you have the earlier, simpler one, then it becomes more complex.
Bu we don´t know, post a couple pictures: front panel, back panel, and a couple PCB closeups so we can check whether there is an unused part of the PCB or not.
So far we are mostly guessing :)
Also post tank codes and for good measure, measure input and output coils DC resistances.
Hello,
Here are the photos. As you can see it has spaces for reverb on PCB.
Ok , I have good news and I have bad news.
Good news: you have an incomplete "reverb" amp, , potentially capable of being completed
Bad news : it does not match any known schematic.
Cearly Fnder switches suppliers as often as they chang underwear, this one seems to be a certain Thai Yih something and apparently each one uses his own schematic.
I already suspectd that when I saw an MN5201 switching Op Amp, normally used by Marshall.
personally; I´d write Fender stating amp model and serial number "for servicing".
If they send you theproper schematic AND it covers both versions like the one above, you are done.
Post it here too, so we see what you have.
Hello,
That being the case and, the circuit will support a reverb. Where could I plug it into the the existing circuit ?
If I obtain the reverb tank from the Fender Frontman 15R and use that circuit how hard would it be ?
The circuit is already there, it is just devoid of parts, so you'd inject the reverb ibnto exactly where the board has it now, along with the support circuits that are not yet there. You posted a schematic earlier with a section for rerverb model only. Does that drawing not match your board?
Hello,
It only has the number of the resistors as per R102 -R102 ect. No values on any of them . I have just sent a letter off to Fender maybe they can enlighten me as to the value of the missing parts.
You are also correct about everything is there, in out ect. just the values missing.
Quote from: J M Fahey on January 26, 2017, 04:14:52 PM
I already suspectd that when I saw an MN5201 switching Op Amp, normally used by Marshall.
JM, that's a 5218, not 5201, so standard dual op-amp. :)
SpareRibs: Is this a USA amp or some other country?
Can you post a picture showing the number on the output IC (mounted on heatsink) and also of the chassis front panel.
Hello g1,
The amp is made in Taiwan. The two pieces mounted on the heat sink are D313-E7F3. Each piece has those two numbers on them. They are part of the output.
I cannot take a picture of the face plate right now as it is disassembled.
Quoteeverything is there, in out ect. just the values missing
You had been asking WHERE to tap in and out. Thoe extra parts for THEIR circuit have no values, but you should be able to tell where in teh dry circuit they tapped. Then you can use any drive and recovery circuit you like using those tapping points. One could probably use similar circuits to fill in the spaces, ignoring the part numbers.
Hello,
It has in and out for a reverb tank, not into and out of the existing circuit. Without a schematic showing where to tap into and out of the circuit I am still at a loss, as well as what parts are needed.
I already know it's just a cheap amp to you but, I would like to upgrade it as I have had it since 1987. It has been very useful and dependable.
The few upgrades like the 12" speaker and staggering the clipping diodes made a remarkable difference. Now I think adding a reverb tank would only enhance all of that.
I am sorry to have created such a problem for you, I only ask on this forum because I thought it would solve the problem for me, was I wrong ?
I think the last page of attached schematic should make you happy. :)
Just does not give the number for the transistors or reverb tank. Maybe Fender could tell you that.
edit: 8EB2C1B should be the correct tank
The board has the connector places labelled in and out for the pan, but the rest of the circuit traces are still there for the reverb circuit. So we look for the parts in the existing stuff that has the takeoff and return feeds for the reverb circuits. For example, follow the traces back from the top of the reverb pot and see where they come from.
But g1 appears to have found the relevant drawing, so it becomes moot.
Hello,
While looking on the internet today, I found that in 1986 Fender marketed a Squier 15 reverb amp for sale in Japan. That may be why my amp has the reverb circuit traced onto the PCB board.
If I can get Fender to send the schematic for that I think the problem will be solved.
Did you look at the last page of the file g1 posted?
Hello,
Thank you g1, that was very informative. I will have to look into the transistors. I printed out the last page. I was so glad to get that much information at one time.
Q101, Q103 can be general purpose NPN transistors, originals were probably 2SC1815 or similar. Q102 would probably work fine with another 2SC1815. The series 330 ohm 2 watt resistor tells me that for that resistor to dissipate 2 watts, there would have to be 77ma current. I am sure they never designed it even close to that, and teh 2SC1815 is good for 150ma anyway.
ANy general NPN type should work, lower the noise the better. I recommend you stay with Asian types, the 2SC or 2SD series. You could use 2Nxxx US types, but the leads won't line up with the holes right.
The resistors are on the drawing, and other than the two 330 ohm 2 watt, make the rest the same wattage as the rest of the resistors in the amp.
Cap voltage isn't on there, but the most across the circuit is 42v. And I don't see more than 20 volts or so an any of them. SO 35v or 50v should suffice.
Hello,
OK Enzo, that all seems very reasonable. Another thing that has perplexed me is C-102 that simply states 100 with no decimal point and C-107 that just has 22. The rest looks all right. I made a list for the capacitors and resistors, and now the transistors.
I will now just have to research which reverb tank to use. I don't want to use one that is either not large enough or to to big.
It also seems that the Fender and the Squier circuit are almost identical other than the reverb.
Thank you for the thought and effort you put into explaining the transistors
The size of the reverb doesn't matter to the circuit, only the impedances.
All caps are on the print in microfarads unless otherwise noted. So 100 and 22 are 100uf and 22uf, the rest are also in uf. Look upper left at C2, C3, note they are 10pf and 47pf? They have the units written, all the other ones don't, and are thus in uf.
Reverb tank is 8EB2C1B.
Hello,
Thanks g1. I have one more question. Q7 and Q8 are marked D313-E7F3. Next to that are the the 3 holes on the PCB for another transistor, marked 102. In addition there is a hole drilled in the heat sink to mount it. so could 102 also be a D313-E7F3 ? All 3 are in line.
A 2SD313 would work. But the fact the two output transistors are that type is irrelevant.
Hello,
Thank you Enzo. The space for the 2SD313 is configured for that transistor. the other two spaces have the flat sided circle are the 101 and 103 that would use the 2SC1815.
Hello,
I am ordering a Accutronics Reverb tank today. It will be new so there should be no problems with that however, the transistors 2SC1815 on the Mouser website come up as obsolete. Now what ?
Well, my suggestion was for 2SC1815, not 1851. And it was just a general purpose transistor I happen to stock.
Hello,
I mistaken 2SC1815 is what I actually intended type. I will be going to our local electronics supplier today to see what he can come up with.
The 2SC1815 is listed as obsolete by Mouser.
Thank you.
Quote from: SpareRibs on February 01, 2017, 10:57:01 AM
Hello,
I mistaken 2SC1815 is what I actually intended type. I will be going to our local electronics supplier today to see what he can come up with.
The 2SC1815 is listed as obsolete by Mouser.
Thank you.
DigiKey has them.
http://www.digikey.ca/products/en?keywords=2SC1815&from=home (http://www.digikey.ca/products/en?keywords=2SC1815&from=home)
Hello,
Yes DigiKey does have them, price less than $1.00, Shipping $8.00. I am working on a budget amp on an economy budget. That is one of the things that infuriate me, there low prices, and the massive shipping costs.
Thank you for your effort, but I have to look locally.
Any small signal transistopr NPN will worl, just watch voltage to fit within power supply.
https://www.aliexpress.com/wholesale?catId=0&initiative_id=SB_20170202133438&SearchText=2SC1815
Hello,
Yeah!!! Today I got a D313 transistor. It came from our local audio electrical supply. He didn't have the (2) 2SC1815's I needed. He wanted to sell me a substitute but I wanted the exact part because I am following the schematic exactly and, I do not want any variables to pop up.
Still waiting on the reverb tank, should be here any day.
Any similar spec part will work, this is just a small guitar amp, not precision lab gear.
Hello,
Be that as it may, to have the exact parts will give me a better chance of the whole circuit working.
I know you are probably right however, I do not know which piece would be compatible and if not why. Given that I would be building a problem into it as opposed to improving upon it.
I know it seems simple to you but to me its step by step until the results are achieved.
I look at it as rebuilding an engine it,may look fine and turn over, but will not start because the wrong camshaft was installed.
OK, there is absolutely nothing wrong with sticking to your guns. You will never go wrong using the original spec parts. If I told you the extremely common 2SC954 would work there, if you are not comfortable with that , then don't. SImple as that.
I'll see your automotive analogy and reply with cooking. I have a recipe for baked beans with burger. It is on the label of some Van Camps Baked Pork and Beans. CHop some onions and brown them with loose meat burger browing in a large skillet. Now dump a can of beans into the meat and stir. A sort of basic chili. You want to try it too, but all you have is Campbells Pork and Beans. WIll it work? Of course it will. Will it be the same? NO, it will have the taste difference between the Campbels and the VanCamps. Not much difference.
Yes, the wrong cam shaft wont work in an engine. If this is a Olds 442 1976, a Ford cam won't work. But I suspect if you couldn;t get a Delco 76 442 cam, a NAPA 76 442 cam would also work. Or if it wanted a battery with posts, and all you had was batteries with screw terminals. The different battery would still work, you just have to put screw ends on the cables.
But enough of all that, just get the parts you want to use, and that will be that.
Hello,
While I am moving right along with the transition, there seems to be a jumper wire that I do not know what it jumps to. It is right below the Reverb in and out.
I am under the impression it ties into Q101 somehow. I would appreciate any thoughts on the matter.
Looks like it *might* be the ground connection for the tank and/or that part of the circuit.
Take a pic of the other (copper) side of the board and indicate which hole is for the jumper.
Hello,
Well OK here goes.
Ok,
Show the location of both holes I have marked in this pic.
Mark right on the copper side of the board with a sharpie or pencil.
A small arrow or circle on the hole will do.
Then take a pic of the copper side of the board, but don't cover any of the board.
Please try to make sure the pic is in focus.
OR....
Harder to do... but if you hold the board up to a strong light with the copper side facing the light...
From the parts side you should be able to see the copper traces "thru" the board.
A good clear pic of that would be excellent.
But it may be very difficult to get the camera to expose properly and have a clear view of everything.
See what you can do. If it doesn't work then do the first.
EDIT;
Look carefully over the whole board for another hole marked "J"
It should might be there somewhere.....
Hello,
galaxiex, The hole in the upper left hand corner where you placed the arrow has nothing behind it, no copper leading to it, nothing. There are no more J's anywhere on the board.
The hole for the jumper wire has a circle around it with an arrow pointing directly to Q101.
Would the jumper wire possibly go to the emitter of the Q101 as that would feed the input for the reverb tank ?
Also why doesn't the jumper wire show up on the schematic ?
Looking at the schem I kinda doubt that it goes to the emitter of Q101.
I don't know why the jumper doesn't show on the schem....
Give us a nice clear pic of the copper side of the whole board,
with the J hole marked and I might be able to figure it out.
Hello,
Here it is. Hope it helps.
Look at it in the schematic, the end pin of the four goes to C103, so the remaining one must be the ground return for the reverb pan drive coil. The arrow is not pointing at Q101, it is pointing across the board somewhere, it means a wire goes there off to somewhere, possible even just chassis.
Hello,
Thanks Enzo that makes sense. Now that makes it powered up, and the other would naturally be ground.
Hello,
I finally found the solution to the jumper. Another circle with an arrow was between C27 and C28. there are a number of connections in that small area, so in my infinite wisdom I was looking to hard to see anything. Those two are undoubtedly to be connected to complete the reverb circuit because the new one goes to the common coming off of the transformer.
Anyway here are the pictures I took of the PCB on both sides.
I will now jump between the two on the top side with a piece of single strand wire, and continue soldering on the rest of the components. Finally.
Enzo, I owe you a can of Van Camp's
Thank You to everyone involved so far, its been a long project, and its not over yet.
Seems to me I said all this.... ::)
Quote from: galaxiex on February 08, 2017, 05:02:09 PM
Looks like it *might* be the ground connection for the tank and/or that part of the circuit.
Quote from: galaxiex on February 08, 2017, 08:11:45 PM
...
Look carefully over the whole board for another hole marked "J"
...
Hello galaxiex,
Yes you did. I said before on this forum, I am not as knowledgeable as most of you guy's. I thought I looked over the board thoroughly, but I guess not.
When I looked at the bottom of the PCB board it may as well have been the Nazka lines.
I was also looking in the area of the first jumper hole for the other one. It was completely on the other side of the PCB
between two large capacitors, surrounded by a lot of other things.
I will try to be more thorough next time.
Interesting project. I've thought about doing the same to my K-20X as it has the reverb on the board just missing components as well.
Can we see a pic of the 12" speaker in this thing? I didn't think it would fit!
Hello,
It is housed in a new cabinet. I made it out of 3/4" x 8" pieces of pine shelving. To install it in the original cabinet I removed the bottom and used two pieces of wood 3/4" x 2" to add an extension to fit the speaker.
Quote from: SpareRibs on February 12, 2017, 09:34:06 PM
Hello,
It is housed in a new cabinet. I made it out of 3/4" x 8" pieces of pine shelving. To install it in the original cabinet I removed the bottom and used two pieces of wood 3/4" x 2" to add an extension to fit the speaker.
Interesting...still, I'd love to see pics. Projects like this are always interesting to me!
Hello,
I will post them as soon as I am finished. I spent the day today repairing a tire. It had a self tapping screw in it that I didn't see for a few days. It kept losing air. The only tire shop here (Les Schwab) in town is constantly backed up. Any way they wanted $13.50 to take it off the rim and put a patch on from the inside, when they could get around to it. I just went to the auto parts store and bought the old fashioned kind of tire plugs. I hadn't used them in years and wasn't sure they were still available. I am surprised they were. I spent a few hours today going over the circuit of the Squier amp to be sure all of the electrolytic capacitors were facing the right direction one by one, all of the resistors were in the right positions, and of the proper value.
So it all checked out. It will probably be ready for final assembly tomorrow. I still have to mount the reverb tank in the cabinet. The holes have to be drilled, and the tank mounted, and length of in and out leads determined. So until tomorrow.
Hello,
Success !!!!! I cranked up the amp today. The reverb tank really adds depth and richness to the sound. I was amazed that it took away all of the solid state brittleness. It really sounds as close to a tube amp as I am going to get for less than $150.00.
I can't thank everyone enough for all of the input and assistance through all of this. With all of the soldering and
grubbing around for parts it finally came together pretty good.
I don't know how to download sound clips, or even record on the computer. I wish, because I would like to share the results with everyone.
Thank all of you again.
Nice to hear you got it working.
How about some pictures of the board with the new components? :)