Hi I want to start after a long hiatus due to circumstances & health my first First Watt based amp.
I am due to physical injury a pensioner. So my budget is very limited. BUT necessity being the mother of invention I have become a gifted scrounger.
This is what I have on hand. A 18 0 18V 160 Va torroidal transformer. Brand new scored fom Jaycar 1/2 price clearance 240v Aust because that's where I live.
Several enclosures 1, Farnell 340 X 420 X 90 rack mount. 2, 185 X 115 X 58 Hammond die cast enclosures. 4, NOS Philips 33000 uF 63V Q caps. 4, very slightly used ELNA 8000 uF CE-W 75V 85°C.
My question is with what I have here on hand which would be the best First Watt to start with?
My hobby is speakers so I have a multitude so choose from. 120 litre Philips AD 12100 W8 fullrangers with Fostex bullet tweeters kicking in above 10Khz. Isophon Orchester 2000( can be 4 or 16 Ohm) with sealed 60 Litre cabs. Both of these in the 93 to 95 dB efficiency range. My custom HDF cab 8in Peerless HPD 3 ways with outboard XO's all high end component eg Mundorf silver gold oil Audyn pure copper foil etc about 89-90 dB eff & 70 litre TL cabs. By the way did I mention that they sound inredible? Lastly a motley ever changing crew of 2 ways 4-8 Ohm from about 87 to 90dB eff. If I wanted to narrow it down to a specific purpose it would be to drive the fullrangers & the two ways near field on PC duty.
Hope someone can asist me if not it is only a matter of time before I find out for myself. But the assistance of someone with experience would save some time as that is for all of us a finite resource. I had initially wanted to build a simple chip amp but me thinks that is no real challenge and my guess is it will not touch the SQ of a First Watt.
I am due to physical injury a pensioner. So my budget is very limited. BUT necessity being the mother of invention I have become a gifted scrounger.
This is what I have on hand. A 18 0 18V 160 Va torroidal transformer. Brand new scored fom Jaycar 1/2 price clearance 240v Aust because that's where I live.
Several enclosures 1, Farnell 340 X 420 X 90 rack mount. 2, 185 X 115 X 58 Hammond die cast enclosures. 4, NOS Philips 33000 uF 63V Q caps. 4, very slightly used ELNA 8000 uF CE-W 75V 85°C.
My question is with what I have here on hand which would be the best First Watt to start with?
My hobby is speakers so I have a multitude so choose from. 120 litre Philips AD 12100 W8 fullrangers with Fostex bullet tweeters kicking in above 10Khz. Isophon Orchester 2000( can be 4 or 16 Ohm) with sealed 60 Litre cabs. Both of these in the 93 to 95 dB efficiency range. My custom HDF cab 8in Peerless HPD 3 ways with outboard XO's all high end component eg Mundorf silver gold oil Audyn pure copper foil etc about 89-90 dB eff & 70 litre TL cabs. By the way did I mention that they sound inredible? Lastly a motley ever changing crew of 2 ways 4-8 Ohm from about 87 to 90dB eff. If I wanted to narrow it down to a specific purpose it would be to drive the fullrangers & the two ways near field on PC duty.
Hope someone can asist me if not it is only a matter of time before I find out for myself. But the assistance of someone with experience would save some time as that is for all of us a finite resource. I had initially wanted to build a simple chip amp but me thinks that is no real challenge and my guess is it will not touch the SQ of a First Watt.
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those philips are having surround hard as rock , most probably,after all these years ; there is a thread about solving that issue , exactly with Philips 12" which I started ( as memory serves)
I believe some good guys around advised to try with butyl solvent , then applying new surround goo
regarding amp - have you some heatsinks on hand ?
with 160VA Donut , I see only ACA as possible candidate , at least looking in Papa's yard
I believe some good guys around advised to try with butyl solvent , then applying new surround goo
regarding amp - have you some heatsinks on hand ?
with 160VA Donut , I see only ACA as possible candidate , at least looking in Papa's yard
Cheers Zen Mod
on the heads up for the Philips surounds. Will look into it. They sound pretty good as they are but there is always room for improvement.
Please forgive my ignorance but what does ACA stand for? & yes I do have some heat sinks 110 X 75mm X 2. Not pretty but were off an 80 wrms amp so I hope they will suffice. If not I will scrounge bigger. I will mount them on the tops of the enclosure with fins facing vertical for highest thermal efficiency.
Cheers & thanks for the swift reply.
on the heads up for the Philips surounds. Will look into it. They sound pretty good as they are but there is always room for improvement.
Please forgive my ignorance but what does ACA stand for? & yes I do have some heat sinks 110 X 75mm X 2. Not pretty but were off an 80 wrms amp so I hope they will suffice. If not I will scrounge bigger. I will mount them on the tops of the enclosure with fins facing vertical for highest thermal efficiency.
Cheers & thanks for the swift reply.
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Cheers 2 picoWell I guess that would be the best place to start. After my quick search that is what their intended purpose is. Any suggestions on the best op transistors to suit that is readily available & not some unobtainium that seems to be a feature of the species. A quick glance at your DIY shop suggests to me the F6 trannies & board would make a VERY nice amp with even with the lesser mosfet configuration. Hmmm. The ACA is not much money for the entire kit - enclosure. I have known for a long time the valve like sound that transformer coupling can give. Sey hello to my little friend. Little Red 23Kg @1w rms of battery powered custom wound transformer coupled op yumminess.
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The F6 is a great amp. Very straight forward fire up process as well. Only transistors that are "hard to find" are available at store, that would be the Jfets.... the output mosfets are very available from numerous sources. ( I think the store is out right now) The mosfets really arent "lesser" but if you want to go other route member semisouth has some....or did recently. They are more costly than the Mosfets.
Russellc
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Cheers Russellc
That is the one that appeals to me the most. My power trannie suits.
The board layout is super simple. The DIY board sold here is designed to work with parts obtainable here & my Farnell rackmount case has the space to keep the power tranny at a respectable distance + fit all 4, 33 000 uf caps for the Psu. BTW are there any issues using these @ 2 per rail instead of the 4, 15 000 uF per rail suggested that I should know about ?
Cheers
That is the one that appeals to me the most. My power trannie suits.
The board layout is super simple. The DIY board sold here is designed to work with parts obtainable here & my Farnell rackmount case has the space to keep the power tranny at a respectable distance + fit all 4, 33 000 uf caps for the Psu. BTW are there any issues using these @ 2 per rail instead of the 4, 15 000 uF per rail suggested that I should know about ?
Cheers
300VA minimium for stereo. Nothing wrong with 2 x 160VA for Dual Mono Setup though
Conrad Heatsinks in Melbourne
http://www.conradheatsinks.com/prices.html
mf35-151.5
Conrad Heatsinks in Melbourne
http://www.conradheatsinks.com/prices.html
mf35-151.5
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