Is this amp PCB layout familiar?

[CSPRINGER]

I believe this is the PCB for the PV Ryl 8. I do have the parts spec listing - was unsure if it woiuld help?


1. I wonder if any of you experts recognise this layout?
2. If the layourt is a historically conventional one?
3. I wonder what they based it on and if there are any optional Mods - - and how the mods might sound.

Thank you all in advance

PS CABLES:
At the guitar store a fellow compared similiar genereic cables vs Monster cable dnd the generics seemed quite dull and most definately "quieter"/ less eifficient compared to Monster but I think monster are a ripoff and too blingy and the plugs apparently are not well designed and bad for standard recepticles. This simple cable comparison in a small amp sounded like a speaker upgrade with a couple addnl db's sensitivity - I was astonished.

I have been using generic cables and am ordering some Canare gs-6 with Nutrik Silent Plugs for it.

[Enzo]

Where did you get the layout drawing?

Looking at it, and your schematic, I see things like C11 across the incoming mains, R20 on the breakaway LED board, J3 with R2 for headphones, etc. Way too many coincidences to be anything else.

I don;t recognize it, but using the information shown, I can conclude the layout and schematic are for the same amp.

I don;t know about historically conventional. It is two tubes on a circuit board with controls and jacks along one edge. Nothing odd about it, but how many ways can a board be laid out with two tubes anyway?


What did they base it on? Nothing. They sat down and said "why don't we make a little 5-10 watt tube amp, I think there is a market for it." And they proceded to knock out a design. No reason in the world to "base" it on something. A two tube amp is something any competent tube guy can sit down and draw up on a napkin sitting at a bar.

The two preamp stages have 100k plate loads and 1.5k cathode resistors, absolutely the most common arrangement, and right out of the RCA book. Basic single ended power amp and a simple power supply. it is a nice little amp, but it is utterly conventional.

You want to play with the circuit? All the basic rules apply, cathode bypass caps affect both the gain and the low end response. You can play with the plate load resistance to affect gain. You could probably shift the tone control response some with different cap values. And the coupling caps between stages can be changed to affect frequency response. You could mess with R17 to affect the power tube drive. Hell you could even try a 12AY7, might work. Or a 5751. There are only 20-25 parts in the entire signal path, so there is a limit. Oh, you could change R12 and experiment with changing the B+ level in the preamp.



Cables. yes there are dirt cheap cables that sound dull, and there are $50 that sound great. But there are plenty choices in the middle. The leap from $3 to $30 is an obvious sound, but I am not convinced myself that from $30 to $50 is such an obvious step.

[CSPRINGER]

Hi Enzo,
THank you sir for your time...I am learning much here.

Where did you get the layout drawing?

>>> If you mean the PCB one..I pulled it off a University web site. It looks like a drawing/diag that can be used for PCB production. Odd that it is so perfect a match...may have been a students project to create a reproducible PCB circuit for some class? Some students have all the luck...all I got to play with was the tinkertoy set for Organic Chemistry - not what I would call a good time.

Looking at it, and your schematic, I see things like C11 across the incoming mains, R20 on the breakaway LED board, J3 with R2 for headphones, etc. Way too many coincidences to be anything else.

>> I compared it to the pictured I posted here for the amp PCB and it appears to be an EXACT copy.

I don;t recognize it, but using the information shown, I can conclude the layout and schematic are for the same amp.

I don;t know about historically conventional. It is two tubes on a circuit board with controls and jacks along one edge. Nothing odd about it, but how many ways can a board be laid out with two tubes anyway?

>> I have no clue, that is why I am enjoying learning bout tube amps from the more knowledgeable. Interesting that other 5 watt amp mass prod PCB boards to my eyes look more dissimiliar than similiar, with exception of the number of tubes.

What did they base it on? Nothing. They sat down and said "why don't we make a little 5-10 watt tube amp, I think there is a market for it." And they proceded to knock out a design. No reason in the world to "base" it on something. A two tube amp is something any competent tube guy can sit down and draw up on a napkin sitting at a bar.

The two preamp stages have 100k plate loads and 1.5k cathode resistors, absolutely the most common arrangement, and right out of the RCA book. Basic single ended power amp and a simple power supply. it is a nice little amp, but it is utterly conventional.

You want to play with the circuit? All the basic rules apply, cathode bypass caps affect both the gain and the low end response. You can play with the plate load resistance to affect gain. You could probably shift the tone control response some with different cap values. And the coupling caps between stages can be changed to affect frequency response. You could mess with R17 to affect the power tube drive. Hell you could even try a 12AY7, might work. Or a 5751. There are only 20-25 parts in the entire signal path, so there is a limit. Oh, you could change R12 and experiment with changing the B+ level in the preamp.

>> I am hesitant to whip out the iron on this amp as I would miss having a small tube amp to play my racket through . I have already replaced tubes and the speaker. The Speaker upgrate to 8" Weber Blup Pup was worth while indeed. Before I do anything I will order/ build the cables I have selected. Of course I will post up my aural results.

>> Thanks again Sir for your thoughts.
CS


Cables. yes there are dirt cheap cables that sound dull, and there are $50 that sound great. But there are plenty choices in the middle. The leap from $3 to $30 is an obvious sound, but I am not convinced myself that from $30 to $50 is such an obvious step.

[Howlin' Mad Mac]

Here's some mods you could experiment with

1) Swap out C1 & R10 for these values: .68mfd/2.7K

2) Swap out C12 & C6 for these values: 500pfd/.0047mfd

Typically values such as these yeild a more "Brit" sound (Vox, Marshall, Park, Hi-Watt). Current values are closer emulation of "So. Cal." sound. Anyway won't cause any harm if you do the work carefully & should only cost a few bucks. If you incorporate them on a seperate pcb or tagboard you could even switch between them & hopefully make your amp more versatile while still retaining its simplistic elegance.

[CSPRINGER]

Followup////

1)

Swap out
1) C1 & R10 for these values: .68mfd/2.7K

2) Swap out C12 & C6 for these values: 500pfd/.0047mfd

Typically values such as these yeild a more "Brit" sound (Vox, Marshall, Park, Hi-Watt). Current values are closer emulation of "So. Cal." sound. Anyway won't cause any harm if you do the work carefully & should only cost a few bucks.
>>Can you define the difference Brit vs SP CAL in audio, base, treble, OD terms?




If you incorporate them on a seperate pcb or tagboard you could even switch between them & hopefully make your amp more versatile while still retaining its simplistic elegance.

>>> The tagboard sounds like a possibility,,,sounds like a miniboard with the two parts and a switch to switch back/forth to the tagboard....I will look for instructions some where how to do it.

[CSPRINGER]

Any chance you can draw out how I should accomplish this including the additional switch?

I would like to try this and can A/B it and if I choose just install with a small switch as an option so I could always go back and forth.

Thanks

[Howlin' Mad Mac]

Well what I think of as Brittish sounding amp tends to have a bit more of a bright or treble/midrange presence, a little more gain & slightly harsher sound... especially when pushed to clip with a boost pedal. Classic examples of this sound would be old Clapton (Bluesbreakers - Derek & the Dominos days or classic Zep recordings) & the So. Cal. sound more like the classic Fender amps or cleaner/less breakup, a tonal shift more toward bass/lower midrange & a little less gain overall. Great for a more blusey or southern-fried kind of tone. The Fender sound is a bit more deverse IMHO but harder to define... ranging from Memphis or Chicago blues to squeaky-clean country/rock-a-billy tone such as early Elvis or Johnny Cash sort of stuff (especially if you add a touch of reverb) to surf tone (really crank up that reverb tank a-la Dick Dale) to Detroit pop/Motown sound to Summer of Love kind of stuff (Lovin Spoonfuls, Byrds, CSN&Y, etc.) yet can rock out with the best of 'em (Steve Howe of Yes gets his tone from classic Fender Twin Reverbs.) I'm kind of generalizing & in no way wish to diminish the Brit sound but insinuating they're a one-trick pony... but Leo was going for a more hi-fi sound from his amps & the classic circuits from across the pond wanted an equally good, powerful tone yet unique & distinguishable from what America was doing. Hope that helps & that's just my take on tone which by it's very nature is very subjective & I'll be the 1st to admit I'm no expert (just been around the block once or twice.) Oh, BTW a "tagboard" is kind of like a PCB or printed circuit board... a bit thicker & instead of a layer of copper etched away by some sort of chemical it's drilled where you want your components to go & either eylets or turrets are inserted in the holes to solder your components to. Another way to go when working of tube circuits would be to just use terminal strips & solder your components between them & the lugs on your pots, jacks, sockets, etc. Just most (I think) find tagboards easier to create a good layout & visualize the assembled circuit that a bunch of caps & resistors seemingly wired willy-nilly about the inside of the chassis. Again just my take on things... if this helps your understanding of things electronic please use as you wish but there's dozens of ways you can wire things up & one is not necessarilly more or less correct than another. If it works, sounds decent & don't blow up it's a "good thing" regardless of how it's accomplished. Best of luck. Mac

[CSPRINGER]

Followup - MAC et al

Thanks Mad Mac,
I am not so well experienced that the descriptives commonly used make "sense" to me ears. Squeak, chime, growl, grunt, gurgle, fart, splash....they ALL sound like Medical Adjectives the Lovely Nurse Ratchett would use at the Gastro Intestinal Rehab Clinic.

Thanks for the clarification, I hope this is not a Scratch and Sniff Forum.

Most of the stuff I play with this tube amp is NOT in the clean / jazz arena. More in the OD arena but definately not metal (mental?), and I also play Acoustic. My ears really prefer warmer acoustic sound, but this amp plays mostly Brit stuff. Hence my interest in your suggestion as I would like to build a mini board and switch so I could install in my amp and A/B via switch. This would also allow me to tweak the "mod" parts and yet always retain the original sound at the flip of the switch.

I have notated your specific suggestions on a pic of my PCB, location and values. So would you please verify what you posted is what you meant to post?

I will research how to do this via a 'tagboard' + switch as I am visual when it comes to circuits. And once I have things confirmed I will post my plans and then warm up the iron.

Is it correct to assume that the best way to accomplish the A/B is to remove the stock bits, place them on the tagboard with the mod bits, run wire from the orig location on the stock PCB and insert switches? Should I use any special wire to span the few inches from PCB to tag and back? Any recommended switches?

Thank You