Difference between Forte 4 and 4A amp ?

I've owned at LEAST a dozen of these amps. I cycle them thru my system and sell'em to friends. A truly great little amp with the ability to drive low/complex impedance loads. You should hear a pair of them driving my electronicly bi-amped Apogee Stages & Duetta Signatures.

Anyway, the basic difference, besides minor face plate cosmetic differences, is that the 4a has a set of balanced inputs while the 4 does not. Pretty much end of story. There were some minor parts differences as the production line aged but I've found little if any sonic differences even between samples with large gaps in the serial numbers.

There is one tweak I can recommend though and that is to get the 4a and bypass the input selector switch & balanced inputs. Run it with just the single ended inputs. I have noticed a slightly more open sound (even over the 4) running it this way. The tweak is easy & reversible.

In general, avoid the balanced inputs as they have an input impedance that is just south of 1K ohm, which is a very difficult load for most pre-amps (certainly tubed ones).

Voltage gain is 26 DB and they actually work quite well into an Adcom Ace 515 line conditioner, most other conditioning flattens the amp dynamically (and this amp DOES boogie). A Wire World Aurora power cord is a nice upgrade as well.

Good Luck, you have a fine amp!!

Drew & 1953 both offered a good bit of info on these amps. As mentioned, the main differences between the 4 & 4A was that the 4A had balanced inputs. Personally, i consider the Forte' amps some of the best buys in audio. The fact that most of them sell so cheaply has made me both quite happy and quite perplexed. Like 1953, i have had quite a few Forte's. The fact that he's running these "budget" amps with speakers the calibre of Apogee's should tell you something. The fact that the Apogee's are VERY tough loads should also tell you something about the "intestinal fortitude" of the "little" 4's / 4A's also.

I've had everything from the 1A to the 3 to the 4A and the 6 and 6A. All of them sound very sweet, airy, etc... Some moreso than others but none of those that i've owned would disappoint. I'd assume that the others sound very similar. Hearing one of these "budget" or "baby" versions of the more costly Threshold amps can really open your eyes and ears as to how good SS can sound for reasonable money. Don't expect massive bottom end "slam" out of these amps though. They are not a Krell or Perreaux. The common word used for these amps, and you'll notice it in almost every description of them that you read, is "sweet". As such, "sweet" and "brute" rarely go hand in hand.

Power ratings have varied somewhat depending on what you are using as a reference. Even the factory was "confused" in some of their own literature. Out of all of the Forte' amps ( 1, 1A, 3, 4, 4A, 5, 55, 6, 6A, 7 ), the 4 / 4A is the one that offered the most consistent ratings. Everything that i have seen about these ALWAYS states 50 wpc @ 8 / 100 wpc @ 4. I would call this an extremely conservative rating as this amp can drive just about anything you throw at it (within reason). Keep in mind that i am typically a "more is better" kinda guy when it comes to wattage, so long as the "quality" of wattage does not suffer along the way. One reviewer stated that the Forte' 4 series played louder than ANY 50 wpc amp had the right to.

I hope you enjoy your purchase. So long as you're not expecting to play hip-hop at lease breaking levels, i think you'll find it to be one of the "best buys" that you'll make in your audio career. Sean
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I have owned a forte 1a since 1991 and it sounds great for the money.. I would love to get a 100+ watt Threshold but wonder how much different or better it would sound for the thousands $ more.. I am not familier with the model 4 or 4a but would stay away from the 3. Only other amp I would consider for the price range is an Eagle.

Xiekitchen, out of curiosity, what don't you like about the 3 or feel that it should be avoided ? You can lay it on the line with me... : )

As to Elizabeth's comments, all of the Forte' amps run hot and sound best after being left on all the time. I find this true of most amps that run Class A or rich Class A/B. You can't stuff these into enclosed racks since the heatsinks are on the sides and they do run so warm. Sean
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