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Comment by Paul Craig on April 7, 2019 at 7:00pm

Little battery operated low watt solid state amps like the one your speaking of would use a 10k to 25k volume pot, 1k to 2k gain pot and a 100k tone pot with a 100n or .1uf cap.

Comment by Daniel Walter on April 5, 2019 at 9:44am

Paul......question, tangentially..........regarding practice amps, would you want at 250 or 500 pot for volume.........specificly a 2,5 watt amp, 15 watt 6'' jenson speaker........the tone pots for an amp, would they use a cap.? thanks!

Comment by Paul Craig on April 2, 2019 at 8:25am

Hey Taff, for some unknown to me reason, I missed your first posting on this subject. I see that we were definitely coming from the same direction.

A couple posts down you mentioned Strat pickups and that got me to thinking of the many Strat guitars that I've had over the years. The one thing I didn't like about them was that the bridge pickup was always too bright and some were even shrill. The reason for that, no tone circuit just volume only. Strats always had 1 volume and 2 tone pots, but the tone pots were assigned to the neck and middle pickups, not the bridge. Many Strat users started modding their guitar's wiring to include the bridge pickup. I discovered a different scheme that moved the middle pickup's tone pot to the bridge pickup leaving the middle pickup volume only. Benefit of that setup was taming the bridge pickup and brightening the middle while also increasing the "Strat Quack" in position  4 on the switch. The original tone pot on middle and neck pickups resulted in less quack sound when both were chosen.

In that scenario, less is definitely more. Neck position pickups can be too dark so a volume only can be beneficial there also. Exceptions to the rule. ;) 

Comment by Paul Craig on March 30, 2019 at 5:40am

16ohms would be the result for 2 - 8ohm speakers in series and would be too much load. That would overwork the circuit and slowly burn them out. Wired in parallel would work at 8ohm load, but you wouldn't get any real benefit from it because you would be splitting the signal.

Old Tube Amps had output trannys that could be set to either 4ohm - 8ohm - 16ohm to allow changes in speaker cabinets being used. Example being a 4x10 cab would have 4 - 4ohm speakers in it wired in series would produce a 16ohm load or 2 x 12 cab of 8ohm speakers producing a 16ohm load.

When older amps had a external speaker jack, it was rated the same ohm level as the regular output jack and you could have more speakers running at the same level without splitting the signal because the output tranny had second output for it. Those amps were more expensive. Early models just split the signal and were rarely used because there was no real benefit.

Comment by Daniel Walter on March 30, 2019 at 3:27am

Paul, what about if you want to use two 8ohm speakers. parallel, correct? what would you get when two 8om's are wired in series?

Comment by Daniel Walter on March 29, 2019 at 9:26am

wow. thank you again Paul! ground to positive, for series, great!

Comment by Paul Craig on March 29, 2019 at 7:26am

In a small low output amp, the 4ohm speakers seem louder to me than using the 8ohm speakers and those amps will usually take either speaker.

You can wire 2 - 4 ohm in series for a 8ohm load.  That would be signal positive wire from amp to - positive terminal of speaker 1 - ground terminal of speaker 1 to positive terminal of speaker 2 - and ground terminal of speaker 2 to ground wire of amp. That series wiring. If doing series setup, you have to use 2 speakers at half the output ohm or you'll put too much load on the output circuit/tranny and burn it up.

Parallel wiring would be both positive terminals to amp signal/positive wire and both ground terminals to ground wire of amp. 2 speakers in parallel won't sound as good as 1 speaker would because it would be splitting the output. It would be weakening the signal, so it would be best to have a power boost circuit or just run 2 output channels.

Comment by Daniel Walter on March 29, 2019 at 6:53am

Thank you Paul. So i guess you can use both 4ohm and 8ohm speakers on the same amp if the wiring is correct? do you prefer 4 ohm speakers over 8ohm? and just to be sure i have this correct, wiring in series means jumping the positive wires from one speaker to the next, and  suppose the negative wires also, so you end up with two leads? and parellel is having each speaker's wires going to the same connection?

Comment by Paul Craig on March 29, 2019 at 6:10am

In a stage setting - your amp becomes the preamp with controls set for optimal tone - the board/PA becomes the power amp for optimal output levels - the guitar's controls become the tone EQ and volume boost to be fine tuned for the player's needs at the right time or for the mood of the song.

Comment by Paul Craig on March 29, 2019 at 6:02am

The amp or soundboard will need to be set for your best sound whether we have pots or not. Having pots in our guitar is more convenient for us. The argument for no pots for wide open output sound can easily be handled by changing pot/cap values.

If the pots really make your guitar sound less than optimal to you, then simply changing pot and cap values can help you get that sound or maybe you need a different pickup for that type of sound like a Dynasonic, Filtertron or Trisonic pickups. Some pickups are known for bright tone, some for fat midrange tone and some for bass tone. Some have more twang than others.

Another good reason for pots on the guitar is that amps and guitars don't always sound their best will everything turned all the way up. When you setup the amp's controls, there's a process involved to find the "sweet spot" for each amp by finding the right control settings for the best sound. So if your guitar doesn't have pots, you have to adjust the amp's controls taking it off the sweet spot. If you have pots on the guitar, the sweet spot stays intact and you can turn the guitars controls up or down for the mood of the song while keeping it all in place. Those guitar pots become a second chain of pots( Master Controls) for fine tuning like Taffy was speaking of.

There are stereo amps and mono amps. Most of the so called stereo amps are just dual channel mono amps that claim say 20watts of output, but in reality they are just 2 output channels of 10watts. It fools our ears because we hear it from 2 sources at the same time for a fuller sound. Older 10 or 15 watt amps could get very loud depending on what speaker is involved and they usually had a jack for a extension speaker for more sound. Now days, a manufacturer can take a 10watt amp at 8ohm output and add a second channel and splitting the ohms to 4 ohms for each channel at 10 watts through 2 - 8' or 10" speakers and sell it as a 20watt amp for more money. 2 - 4ohm speakers in series will operate on 8ohms. We think that we're getting more output, when we are just getting a second speaker. A speaker moves air. The bigger the speaker, the more air is moved. adding another speaker moves more air and doubles the effect while keeping the same operating power and the only cost to them is a few caps/resistors and another speaker. So it's more money at minimal cost and marketing.

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