Want a tube amp. Tell me what should get...

[RockysDad]

Noob here and sorry for another of these questions...

I did do a search and am more confused then ever with all the choices therefore am asking you folks out there to help me chose something.

Here's what I have at the moment. I have a pair of TL Fostex FE167 single driver speakers rated at 95dB and a pair of Snell Type J/II rated at 92dB. I listen to new age, new jazz, vocals like Norah Jones and acoustic guitar with some Fleetwood Mac and classic rock thrown in. I just built a Bottlehead Foreplay as a preamp and want to keep using that since I built it. Budget is $500-700. Kits would be prefered but a schematic and parts list would do. I want the vocals clean, clear and in the same room as me. Bass would be solid and tight. I'll mostly be using the Fostex speakers and use the Snells as my rock speakers.

So what do you recommend? My list of questions for this is..
1) how much power do I need?
2) what output tube should I use, ie. 300B, 2A3, etc.
3) what circuit topology, ie. PP, SET, etc.
4) any recommended kits available?

TIA....

[Original Burnedfingers]

Disclaimer...

Please don't take offense at what I'm going to say but I will be blunt and too the point.

First of all your not going to get anything worth taking home in the way of a kit for 500-700 dollars. My opinion here... Can't build anything for this budget either that you would be satisfied with.

Secondly, for what you have for speakers I would suggest at least 35watts per channel. I don't believe the 2A3 or 300B can deliver what you are actually looking for given the efficiency of your speakers.

I would suggest that instead of trying to purchase a kit of meager power that you concentrate on one or two things. 1) Budget more money for your kit. 2) Purchase an exhisting design like a Dynaco stereo 70 or something along those lines that will provide ample power to satisfy all your listening requirements.

Let the rock throwing begin...ducking for cover now.


Joe

[maynardg]

There are often Eico HF20 mono integrated amps on e-bay for very little. Buy two. Gut them and use the iron. Build monoblocks with this schemo - www.arrakis.es/~igapop/iga6550.htm for the EF 86 and 6n1p splitter, but use EL34 PP outputs as per - www.triodeel.com/eicohf22.gif.

Easily in budget and very nice.

[Positron]

As Burnedfingers mentions you are not going to get any tube amp that good, new, for that kind of money.

Try what Burnedfingers recommends, good bang for the buck.

[NickC]

1) You have an efficiency system don't really need that much power but depending on what type of new age you listen to and room size. I run 12watts el34pp into 90db speakers and really is enough for blasting to 110db with slight distortion when complex classical/ new age is played at that volume. To be safe 25 watts should be the fiqure you are to aim for.
4) In kit format the Consonance amps from diyhifi supply retailing at 500usd is certainly a bargain for.

2) You should utilize el34 has IMH0 has the one of the highest power per dollar figure . In pp is 10watts se 4-5 watts and only cost 20usd or less per tube. while the others are much higher. Plus it has a good balance with good midrange. if you have the budget kt88 or 6550 are the tubes for higher power.

3) You must use PP at that price at the power requirement and skill level. for 20 watts and above, you have to utilize transmitter tubes i.e. gm70,211,845,813 and etc

at 500 -700 dollars you should be able to build something from scratch provided the chasis cost is kept low.
output trans for that power level is around 100-200usd (i.e. hammonds)
tubes for 4 pieces is around 50usd. driver are around 20-40usd
mains trans should be around 50usd
go for surpluss stuff and you could build it for cheaper

Kits would be prefered but a schematic and parts list would do.

if you would something along the line do check out my website under the el34 pp. should be suffice for your needs. if you like i could help you source some parts that are cheaper here i.e. caps(polyprop coupling and e.caps ), diodes, transistors, mains and chokes custom is you are willing to pay the shipping.

[RockysDad]

All this time I thought my speakers were pretty efficient! You guys are recommending at least 25W, even 35W minimum? Wow...

Okay, this leaves out SE type circuit designs (I don't know what these sound like anyway but its a mute point from here on, I guess).

So I am going to start narrowing things down now.
1) Something 25W-35W.

#2, 3, and 4. Still needs to be defined.

I'll start researching the Dynaco ST70. What are they and what equivelent system are you talking about? I'm assuming these are vintage systems that will be rebuilt. Is this correct?

I've seen Gabe V. kits and they look pretty good. Any recommended designs there? Any DIY HiFi kits looks good (Still trying to find something within my budget).

Any recommendations for a kit with an unlimited budget (still prefere a kit for my first amp)?

[planet10]

I've heard Decware Zens & Bottlehead Paramours sound just fine with speakers that are 91-92 dB efficient -- actually they sound real good. Perhaps a little limited on playing really loud...

I certainly wouldn't dismiss these kinds of amps. Kits for both of the above start at $500 USD.

dave

[G]

I would go with the MAG1515 from Gabe. With the full rangers or the Snell's with the efficiency ratings you mentioned 12 - 15 watts will be fine. Hell you might even want to try triode strapping the EL84s and see what that sounds like. I listen primarily to Jazz and at the moment I am using a SE EL84 amp with a pair of Fostex FE266E fullrangers I built and they sound fine with 2 watts. So like Planet 10 says, a Decware Zen might not be a bad way to go either. Either way you will be pleasantly surprised at the sound.

[Morse]

Hi Rocky's Dad;

Your speakers are PLENTY efficient for the low watts approach. For the record, real world measurements of my twin driver FE164's indicate approx 96dB SPL without the 3dB 'room gain' and they do FINE with the approx 4.5 watts per channel I get from my 2A3's run a little hot. With room gain, under real world conditions, I've hit 105dB SPL peaks at 1 metre at red faced max volume, using my RS SPL metre and C weighting.

You can build an amp in your price range or buy one.

To build an amp, see:

http://tinpan.fortunecity.com/saints...mer/index.html and
http://www.angela.com/catalog/how-to/

for schematics.

As a first-time builder, go SET - they're pretty hard to mess up, and the sound is better than what you will expect by a LOT.

Figure about $150-$180 for a power supply (complete with filter choke and caps) and $70 to $200 for OPT's. The balance of the parts are things like a volume control ($3 Radio Shack Alps works fine), binding posts, RCA jacks, wire, valve sockets ($3 to $6 ea), etc. A chassis can be homebuilt or storebought. Personally I prefer to build mine from wood with small metal plates to mount the valve sockets, but everyone has his own opinion there.

If you MUST buy a ready made amp, the answer's a no-brainer: ASL Wave 8 monoblocks. Figure $270/pair shipped (can't remember the exact costs so I rounded up) plus a volume control and source selector. This doesn't have to be anything more than a $3 Radio Shack Alps and a DPDT in a box with some RCA jacks and the right wiring - all of $50 even with some nice RCA's. Put the money you save into some spare valves, more music to listen to, and your retirement fund.

For $500 to $700 you could build a perfectly good 2A3 SET or EL34 SET, etc. You could probably build a 2A3 like mine for that budget, but it'd be just under the line. A 6BM8 can be built even cheaper - I lowballed one a while back for an initial cost under $100 (it suffers from low quality OPT's and a PS that runs warm for my taste, but at moderate volume it's still very nice albeit light in bass response). Taking that basic design and using a GOOD power supply transformer (go Hammond 300 series rather than the cheap 200 series trafos - the 200's run hot and hum) with a higher amp rating than the cheapie I chose will give it plenty of guts. A slightly lowered B+ will help valve life, and the use of Hammond 125ESE's ($62/pair from Angela.com) in place of my $9 cheapies will complete the package and give MUCH BETTER bass response. Ned over at Triode Electronics has Svetlana 6BM8's in stock the last time I checked, or go over to Antique Electronic Supply and see what they have for NOS - whatever. Figure around 3 watts if you run it in pentode mode - which will drive your speakers to VERY loud levels in a small to medium sized room! If you want more power, that 6L6 SET at FI Primer looks inviting, and with modifications could probably be made to work with EL34's if that floats your boat. Don't forget about the 6BQ5 and the 6V6 either - plenty of good designs out there for either of 'em. Hunt around and find something you like.....

Good luck. You've got first rate speakers, and pairing them with a budget DIY amp or a pair of Wave 8 monoblocks will make them really SHINE!

All the best,
Morse]

PS My website is at http://home.earthlink.net/~shidenkai/index.html
Look around and see what can be made for very few $$'s. Feel free to email me if you have questions, particularly about things like the chassis - I've just made a big revision in construction techniques based on previous experience. No point in anyone repeating my mistakes.

[Bas Horneman]

I support Morse's suggestions.

So what do you recommend? My list of questions for this is..
1) how much power do I need?
3-6 Watts
2) what output tube should I use, ie. 300B, 2A3, etc.
2A3
3) what circuit topology, ie. PP, SET, etc.
SET
4) any recommended kits available?
Paramour by bottlehead.
Paramour Parafeed SE 2A3 monoblocks kit - Now $499

I notice no-one asked you how big your room was? 3-Watt is plenty for most 92db certainly for 95db. I have around 3 watts 90db speakers..average size living room...and it is very loud.?? So I am always baffled for calls of 35watt ...and I mean really baffled...

But most of all don't take anyone's word for it... so try to get someone who has a paramour.. and listen to them with your foreplay and speakers.

Cheers and good luck,
Bas