Frontman 25R - Mod it, or Ditch it?

[marlington]

I've been playing guitar now for about 7 years. But it hasn't been until recently that I'm getting serious about it. I've had a Fender Frontman 25R for about 6 years now, and I use it for my Ibanez Acoustic/Electric as well as my Fender MIM Strat.

I'm just not satistifed with the quality and tone that the Frontman 25R anymore. I'm really looking for more of a bluesy sound. I've tested a handful of tube amps and really like the richness that they give.

My question is:
Is there anything I can do to the Frontman 25R to better it's performance?
(i.e. speaker upgrades, etc)

Also, here's a picture of my amp for reference

[black_labb]

a speaker upgrade would probably make quite a difference, but there would still be alot lacking i'd say. i had a fm212r (100w model, probably pretty similar with an extra channel reverb and more power). not too bad if you just want to play something loud enough but tone itnt great. its being used for vocals now.

[Mark Hammer]

The schematic can be found here: Fender Frontman 25R Guitar Amplifier Schematic

There are a lot of points for intervention, although little that would make it a) behave like a tube amp (if that's your taste), or b) behave like a higher-powered amp.

That being said, although 25 watts is enough to manage many situations, the smaller (10") speaker and smaller cab will offer less overall loudness than a larger, more efficient, speaker and larger more efficient cab. Speaker efficiency is rated with respect to how many decibels of sound-pressure level are produced in response to 1W of input at one meter distance. If one speaker is rated at 96db, and another is rated at 99db, the second will prioduce twice as much perceived loudness as the first, even with the same wattage. So, consider a more efficient speaker. The goal is not so much to make you louder. Rather, there may be tones you like that are hard to achieve without moving to levels/settings that introduce too much harshness. Having a bit of reserve power, by making more with the power you've got, might let you tap into tones you like more easily.

The distortion channel could benefit from some different tone shaping. At present, it introduces a midscoop by means of C9/C10/R16/R17. It also doesn't seem to introduce enough"treble-taming" in the distortion channel for my tastes. I've never played one, but just from looking at the schematic, my sense is that it would be a bit harsh.

So, if you can find these spots on the board, try to do the following:

1) Stick a 2k2 resistor between C10 and ground to lift the midscoop a little and make it less pronounced.

2) Stick a .01uf cap in parallel with D1/D2 to roll off some treble at the first clipping point.

3) Stick a 68-100pf capacitor in parallel with R22, to roll off a little more treble at the second clipping point.

All 3 suggested changes, taken together, will introduce a bit more lower mids, and make the upper midrange and treble bite in the distortion tone less intense. This may be more in the direction of the "bluesy" sound you want, and also require less tonal adjustment when switching from clean to overdrive.

[Enzo]

Not quite Mark. If you have a 96db and a 99db speaker, with the same input to them, the 99db one will not be twice as loud. It will be 3db louder, which is the increase in loudness you would have gotten if you used the 96db one and doubled the power.

[Mark Hammer]

Oh......well that's different. It had never been explained to me that way before. Thanks, and an apology for the misinformation.

Given that it takes (according to doctrine) 10x the power into the same speaker/s to produce a doubling of perceived loudness, a mere doubling of power will not be quite as loud as doubling the loudness directly.

Still, when you think about how wildly some folks chase after 40-50W amps because they think that 25W just isn't loud enough, an aural equivalent of "merely" doubling wattage to the speaker is not such a bad deal.

[Enzo]

Or dropping a 100 watt amp to 50 watts.

Or worse yet when they decide they had better take the 25w amp over the 30 watt amp for loudness reasons.

[Mark Hammer]

Damn straight. Wattage is one of the most widely misunderstood concepts in the music world. Headroom is just behind it.

[Steve A.]

Damn straight. Wattage is one of the most widely misunderstood concepts in the music world. Headroom is just behind it.

Well, I think it is easier to agree when an amp has very little headroom. You have a nice clean sound but as soon as you try to turn the volume up it starts to distort. Like the Crate V18 and the ZT Lunchbox... the last two storebought amps I bought.

But I understand your point- with a *normal* amp there are mods and tube swaps which will allegedly increase the headroom but I think that a lot of that is smoke and mirrors... although it is certainly true that some amps do have much more clean headroom than others.

Thanks!

Steve Ahola

[RockinAngels]

Hi Mark, your reply on post 920 has caught my attention. I've been searching for certain answer on this tone modification issue for 2 of my Fender Frontman 25 and I believe you can help me. I operate a small jammin' cafe in Phuket and this amp I'm using have live up to a good sounding amp of Fender.
My main guitar is a Telecaster (CBS) with EMG pickup and a Epiphone Joe Pass (mod for blues playing). My questions are more concern toward the tone when using the Tele with the Frontman 25.
1) What can I do/modify to bring down the tone (high edge) from the treble control on both clean and drive channel. It would be much better if it could alter towards the blues sound.
2) On the drive channel I noticed that there's a big jump on the Gain between 2 to 3. It's not behaving like most standard Fender amp "Gain". I believe the Gain control should go from little drive to heavy drive slowly from 1 to 10 and not a big jump from 2 to 3. As such, I loose control of fine tuning my drive sound and I'm stuck from going beyond 3.
Please advise and thank you for your attention.
Rockin' Angels

[vanslycken]

If you're looking for a cheap solution without much of a hassle... have you tried the Ibanez Tube Screamer (or other overdrive pedals)? I remember when I was younger a friend of mine had a really cheap starters' amp with lousy distortion, but when he used the clean channel with a (cheap version) tube screamer in front of it, it sounded much better. Still nothing like a real (expensive) tube amp, but still a lot better.

[RockinAngels]

Thanks Vanslycken for your comment. Just put it this way, I got enough pedals to test around this amp. For time being just leave the pedal aside and get back to the clean tone issue. The clean channel behave much worst than the drive channel. The tone is too sharp even with the treble down to 1. It's not so much of the drive or effect I want in my sound. I want a "less high" tone or should I say, a normal Fender amp treble control on this Frontman 25R. Before I can put on any effect pedals on my sound at least I should have a clean comfortable tone. I was thinking, why is this Frontman 25R built differently from other Fender amp? Maybe somebody out there has the same problem like mine and a formula to solve it? OK, just in case some info being missed out, I'm talking about using a Tele with this amp. My other guitar with humbucking pickup work fine on it.

[Little_Paco]

Hi,
I own a Frontman 25R, and i recently deicided to change some of the amp's caps for mkt ones, just to try (it cost me about 5 euros).
As it was open, i decided to look for mods, I found this page, and tryied some of Mark Hammer's suggestions.

I wasn't not looking for a tipically bluesy sound, so i decided to not to change anything about the midscoope (wich looked beside like a tedious work).

I just Sticked a 2.2n cap in parallel with D1/D2.
And I sticked a 46pf capacitor in parallel with R22.
The result is interesting, i would say softer (sorry i'm just a french boy i lack some adjectives)

About the caps replacement it's quite interessting, but not so efficient as these two little mods

To conclude i would say the track suggested by Mark Hammer, are cheap and efficients.