Hello all!
I am fairly new to tube amps and hi-eff speakers. I started out by building a Chilli Chang BVR using the fostex fe167e drivers. Very powerfull sound coming out of these using a Marantz 2750 in a smallish room (11'X14'). The Marantz is old and I've heard my speaker's sensitivity (94db) is well suited to SET amps.
Seeing how I can't afford a $3k amp at the moment, and seeing how I'd like to have a complete DIY system...I'm looking at building my own amp. Problem is, I am far from any possible place I can test them out to try. My thought is to build a tubelab se amp, using one of the tube configurations.
My questions are:
1. Would I be better off building something using better components, or go with something like the Dared MP-2A3C that's on ebay right now?
2. If I build my own tubelab amp, what would be a good choice of tubes for someone who likes all kinds of music, likes presence and fullness of sound? I've heard the 45's are good, 300B's are really popular, and according to Dared, 2A3C's are better than the 300B's.
3. I've heard the First Watt amps, specifically the F1 and F2 are good with single drivers as well, even though they are solid state. How do these compare with tube amps and is there boards you can buy to build these?
Sorry, long post. Appreciate any responses. Cheers,
Matt
I am fairly new to tube amps and hi-eff speakers. I started out by building a Chilli Chang BVR using the fostex fe167e drivers. Very powerfull sound coming out of these using a Marantz 2750 in a smallish room (11'X14'). The Marantz is old and I've heard my speaker's sensitivity (94db) is well suited to SET amps.
Seeing how I can't afford a $3k amp at the moment, and seeing how I'd like to have a complete DIY system...I'm looking at building my own amp. Problem is, I am far from any possible place I can test them out to try. My thought is to build a tubelab se amp, using one of the tube configurations.
My questions are:
1. Would I be better off building something using better components, or go with something like the Dared MP-2A3C that's on ebay right now?
2. If I build my own tubelab amp, what would be a good choice of tubes for someone who likes all kinds of music, likes presence and fullness of sound? I've heard the 45's are good, 300B's are really popular, and according to Dared, 2A3C's are better than the 300B's.
3. I've heard the First Watt amps, specifically the F1 and F2 are good with single drivers as well, even though they are solid state. How do these compare with tube amps and is there boards you can buy to build these?
Sorry, long post. Appreciate any responses. Cheers,
Matt
Hi Matt,
I have recently completed a pair of Half Chili Chang BVR using the older FE167 (not E) in addition to my diy 3 way Onken/JBL based system.
The HCC is not all that easy to drive actually, but 8Wrms per channel of 300B triode SE power seems adequate in my experience even with 5dB of BSC. Baffle step compensation is per Martin J King and it made a world of difference to the sound. (and measurements) Perhaps with the CC you do not need the BSC.
I would strongly recommend one of George's Simple SE amps using KT-88 in order to maximize output power unless you can spring for the Tubelab SE using 300B which is significantly more expensive to build, but not a real deal breaker as you can get the bits and pieces over a few months.
I built the HCC for fun and in order to have a decent FR speaker system for use at the local audiofest I host annually. (Living room based demos) Not my daily driver.. 😀
I have recently completed a pair of Half Chili Chang BVR using the older FE167 (not E) in addition to my diy 3 way Onken/JBL based system.
The HCC is not all that easy to drive actually, but 8Wrms per channel of 300B triode SE power seems adequate in my experience even with 5dB of BSC. Baffle step compensation is per Martin J King and it made a world of difference to the sound. (and measurements) Perhaps with the CC you do not need the BSC.
I would strongly recommend one of George's Simple SE amps using KT-88 in order to maximize output power unless you can spring for the Tubelab SE using 300B which is significantly more expensive to build, but not a real deal breaker as you can get the bits and pieces over a few months.
I built the HCC for fun and in order to have a decent FR speaker system for use at the local audiofest I host annually. (Living room based demos) Not my daily driver.. 😀
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Thanks kevinkr!
The Chilli Chang seems to have plenty of bass to me. I tried using a Radio Shack SPL meter and graph paper to plot frequency response, I can't say that I gleaned anything from such a set up, haha😛 I know that they are the best that I've heard...but I also haven't been exposed to high end audiophile equipment either.
Would a KT-88 still constitute a SET. Is it a DHT (not sure what the difference is but chatter suggests its better)?
Thanks for the help!
Matt
The Chilli Chang seems to have plenty of bass to me. I tried using a Radio Shack SPL meter and graph paper to plot frequency response, I can't say that I gleaned anything from such a set up, haha😛 I know that they are the best that I've heard...but I also haven't been exposed to high end audiophile equipment either.
Would a KT-88 still constitute a SET. Is it a DHT (not sure what the difference is but chatter suggests its better)?
Thanks for the help!
Matt
Check out the Sweet Peach thread - a very nice tweakable SE amp that uses the superb and available FU50/GU50 tubes in triode mode.
We're still experimenting but the amp is capable of some incredible sounds with only a small amount of modding so the OPTs etc are fine. It's cheaper than a kit too 😉
We're still experimenting but the amp is capable of some incredible sounds with only a small amount of modding so the OPTs etc are fine. It's cheaper than a kit too 😉
If this is your first amp, stay away from such exotic and expensive tubes and designs. really what I'd recommend is a 6L6 or kt88 based SET. The big question for you would be which output transformer to use. These are really what makes the amp, more so than tubes. Pick an OPT then pick a power transformers.
One thing, do NOT build any tube amp that you do not fully understand how it works that you can't debug or fix. The problem with a PCB is that it allows you to get in over your head and build something you don'nt understand, just be stuffing parts. That's a mistake. A point to point build allows yu to go slow and build one section at a time, test it out and then continue.
SET = single ended triode. Single ended, meaning there is only one power tube per channel. (You can parallel power tubes and still be single ended, but that's a technicality). Triode, meaning there are only three elements at play within the power tube. Those elements are the cathode (at or near ground potential, and electrons flow from it), the control grid (which regulates the flow of electrons) and the anode (where the flowing electrons are collected). Tubes such as the 6L6 and KT88 are actually pentodes (they've got screen grids and beam formers inside) but you can "strap" them as triodes by connecting their screen grid to the plate. The connection is most often made with a 100 ohm resistor.
DHT = directly heated triode. Triode is already defined up above. Indirectly heated tubes such as the 6L6 and KT88 have a cathode sleeve (hollow tube) with the heater filament inside. The filament heats up the cathode sleeve, liberating electrons. Directly heated means the cathode and the heater filament are one and the same. The heater filament itself emits the electrons. There are a few technical difficulties inherent with directly heated tubes. Perhaps the most significant is that each tube's heater requires a power supply which is separate from the others. Directly heated tubes are also more likely to suffer from audible hum if AC voltage is used for the heater supply.
DHT = directly heated triode. Triode is already defined up above. Indirectly heated tubes such as the 6L6 and KT88 have a cathode sleeve (hollow tube) with the heater filament inside. The filament heats up the cathode sleeve, liberating electrons. Directly heated means the cathode and the heater filament are one and the same. The heater filament itself emits the electrons. There are a few technical difficulties inherent with directly heated tubes. Perhaps the most significant is that each tube's heater requires a power supply which is separate from the others. Directly heated tubes are also more likely to suffer from audible hum if AC voltage is used for the heater supply.
Sorry for the extra "T". I meant "really what I'd recommend is a 6L6 or kt88 based SE amp" We all know that neather the KT88 nor the 6L6 are triodes..
But I'll say again, what you should build is a very simple amp. Later if you want builld another amp. In fact it would be great if you played guitar, that way your first attempt could be a small 5W guitar amp..
Thank you for such great advice! I'm taking your suggestions to build something cheap...along the lines of the kt88. I ordered a kit from Decware to build their se84c amp, but its been a month and no kit. And I got to thinking, I tend to push the volume a bit at times, and even though my speakers are efficient, 1.8 Watts may not satisfy me. I'm thinking 8W+ SET amp is what I'm looking for.
ChrisA, I've played guitar since I was 12 yrs. old (32 now), and I've never owned a tube amp (wish I would have). Don't play guitar as much anymore now that I'm married! Motivation gone..hehe.
I think that I'm heading in the right direction. My ultimate goal is to produce the most direct signal path from source to driver, and with the best sound possible. I don't like the idea of components making up for bad design, engineering, etc. Minimalist approach. SET, from what I've heard is a just that, simple.
ChrisA, I've played guitar since I was 12 yrs. old (32 now), and I've never owned a tube amp (wish I would have). Don't play guitar as much anymore now that I'm married! Motivation gone..hehe.
I think that I'm heading in the right direction. My ultimate goal is to produce the most direct signal path from source to driver, and with the best sound possible. I don't like the idea of components making up for bad design, engineering, etc. Minimalist approach. SET, from what I've heard is a just that, simple.
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