Tube amp for Forte's

Luckytiger

Member
I have a great sounding pair of Forte' I's with the ALK crossover upgrades. I have been playing around with various SS amplifier combinations and believe I am finally ready to come over to the dark side. Looking at perhaps some Eico mono-blocks, or an HH Scott integrated. Has to be American. I would like to keep it under $1K with mod/restoration. Tell me Forte' fans, what are you running? What would you never give up?
 
I don't recall the efficiency rating for your Forte's (100dB/W?) but you might get by nicely with just a few watts. This opens up the realm of the SET. One the best bargins ever are the George Wright 3.5W monos running 2A3s. You can get them used in nice shape for under a grand :)
 
I'm running a Dynaco ST70 into my forte' s and it sounds great, either tube or SS preamp.
Bob Latino sells a nice ST70 kit for around $700.
 
I know that you said it had to be American but if you bought ARC you would be buying Chinese designed and built iron ,has been for a long time. So Antique Sound Lab AQ1003DHT and switch out the stock 12AU7 tubes for better sounding 12BH7 and you will be done like dinner. Set12 has used one of these and was very impressed and he is a hard man to please. You can likely find one used for $5 -600.00. Best regards Moray James.
 
With my Fortes, I've used restored Fisher 500C and 400 receivers(35 and 28 watts), restored Heathkit UA-1 mono blocks(14 watts) and presently a Decware Torii MKIII push pull (25 watts). All sound great. Dependent on your loudness needs and room size you can go anywhere from 2 watts up. Check out Decware. Great company. All their amps are hand made in Illinois. Wonderful stuff.
 
going to be hard to buy used and rebuild plus re tube with quality tubes for under the desired budget Not impossible by tricky I think. If you see an old Radford STA25 buy it, it is half American as David Hafler was co designer of the UL transformer it uses along with Arthur Radford. Nice amp used to have one and please don't ask. Best regards Moray James.

PS: the Leak ST70 would be the British equivalent of the Dynaco (David Hafler) ST70 I have had one of each of these too nice and the ST35 Dynaco is also a fine little amp had one of those too oh boy.
 
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Check with forum member Dan055. He restores Heathkits, Dynaco, etc. I bought those UA-1's that I referred to above a few weeks ago from him, and he recently sold a similar pair within your budget. His stuff is amazing, like new, and he stands behind everything he builds. A great guy to boot. Well worth an inquiry.
 
Craig (NOSValves) does great work on EICO too and my HF-81 does well with Heresys...Chorus II...Quartets...K'Horns...:D

Bill
 
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I use a Vista Audio I84 a 15wt PP el84 amp on my Quartets which are similar

great sound gets loud inexpensive got mine used for 350.00
 
2A3, 6BQ5, 6AQ5, 6V6, 6L6, EL34, KT88 are all exceptionally fine sounding output tubes and are worth your consideration. For what it is worth rugidized mini tubes are less harmonic than larger versions. With any of these tubes the quality of the iron will be a major determining factor as far as sound quality goes as will circuit and layout. Triode operation is very linear but pentode can sound very good too with great bass quality. A good EL34 amp in PP will give you a solid 30+ watts which can drive just about any speaker you want to good levels so that makes it a very versatile option. I very much like the 2A3 but single ended it does not put out a lot so you need a high efficiency speaker. above say 96 db where three watts will do a good job but in the low 90's you will need more like 30 watts plus. This is dependent upon you listening taste and the levels you like but is a reasonable guide. Your Forte are an honest 95 db efficient so you are in the middle if you don't need really loud then one of the smaller tubes in set operation (6BQ5, 6V6 or 2A3) with top quality iron will not fail to impress you. See which tubes do it for you then start to check out as many different circuits and amps as you can find. Best regards Moray James.
 
2A3, 6BQ5, 6AQ5, 6V6, 6L6, EL34, KT88 are all exceptionally fine sounding output tubes and are worth your consideration. For what it is worth rugidized mini tubes are less harmonic than larger versions. With any of these tubes the quality of the iron will be a major determining factor as far as sound quality goes as will circuit and layout. Triode operation is very linear but pentode can sound very good too with great bass quality. A good EL34 amp in PP will give you a solid 30+ watts which can drive just about any speaker you want to good levels so that makes it a very versatile option. I very much like the 2A3 but single ended it does not put out a lot so you need a high efficiency speaker. above say 96 db where three watts will do a good job but in the low 90's you will need more like 30 watts plus. This is dependent upon you listening taste and the levels you like but is a reasonable guide. Your Forte are an honest 95 db efficient so you are in the middle if you don't need really loud then one of the smaller tubes in set operation (6BQ5, 6V6 or 2A3) with top quality iron will not fail to impress you. See which tubes do it for you then start to check out as many different circuits and amps as you can find. Best regards Moray James.

This is great advice.
 
In my experience, having used my Forte's with a variety of Dynaco, Fisher, Scott and McIntosh tube amps, EL84/7189 amps - although they sounded "nice" - just didn't have enough balls for me.
EL34, 7591 & KT88 based amps have all been good.:thmbsp:
 
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