Luke said:
Hi Arthur,
I used OnSemi MTW32N20E. I posted on the AlephX thread and Nelson himself said they should work fine. I needed some other Onsemi parts so I ordered them as samples and got 40 of them to match from. They were amazingly close right out of the tubes.
I have no way of knowing about the IR's. The bias I was planning to run required at least 8 IR's per channel and only 4 per channel with the MTW's due to their higher power handling and temps. My bridge was running pretty hot so I dropped the bias down. That may account for some of the weaker bass, I don't know.
Mark A. Gulbrandsen said:
Hi Mark,
Thanks for info. Have you built the Aleph 2? Have you compared it to the KSA50?
This A-X sounds OK but it is nothing like the KSA in my book.
I have a few 25-0-25VAC 300VA transformers. Will these work for an Aleph 2?
Thanks, Terry
The Aleph 2's were the first amps that I built after finding this site.... I've built stuff going back to the early 70's but the Aleph 2s were my biggest single project.
The 2's sound great but the bottom end is not as punchy as the KSA-50's. Top end and midrange are glorious and very different from the Krell. I've also built an Aleph 30 and a Mini Aleph. The 30 eas for a friend and the Mini is in use in my shop/computer room and drives a pair of Yamahas from a Sony Walkman(the walkman is the next to go bye-bye).
You need 33-0-33 at least 600 va to build an Aleph 2 monoblock. That guy in NJ you got those Toroids from sells a 34-0-34 600 va job that would work nicely. The 2's do generate alot of heat so over heatsinking them so you can crank the bias is a must!
Mark
hi Terry,
I remember reading your posts about using the OnSemi MTW32N20E. Im not sure they will be causing your lack of bass, but the low bias would mean that potentially if your speaker was dipping to 4 ohm or something, the amp could be starving for current. This could be your problem.
A good idea would be to buy Brunos rectifier pcbs and build some bridges that can handle more current and crank up your bias then see what happens.
But then again, the aleph-x clone may just have weak bass, I dont know.
seeya ab
I remember reading your posts about using the OnSemi MTW32N20E. Im not sure they will be causing your lack of bass, but the low bias would mean that potentially if your speaker was dipping to 4 ohm or something, the amp could be starving for current. This could be your problem.
A good idea would be to buy Brunos rectifier pcbs and build some bridges that can handle more current and crank up your bias then see what happens.
But then again, the aleph-x clone may just have weak bass, I dont know.
seeya ab
Well I do want to say one thing. I've been wondering how the A-X would work with a sub along side so I finally hooked up my B360 JBL. It's been out of the loop since I've had the Leach and the Krell. I think I've found something here. Huge difference with some lows added. I may build a sub to go with the A-X. Very nice.
Blessings, Terry
Blessings, Terry
sounds like the aleph-x is a bit like the normal aleph 2s.
BTW Terry, your transformers would be perfect for an aleph 5.
Its +- 34V and draws 150watts. you would obviously need to use two transformers for a stereo amp.
These really are good amps.
BTW Im impressed at how well and quickly you knock out these amps
BTW Terry, your transformers would be perfect for an aleph 5.
Its +- 34V and draws 150watts. you would obviously need to use two transformers for a stereo amp.
These really are good amps.
BTW Im impressed at how well and quickly you knock out these amps
The thing I disliked about my X's was actually the lack of high end. It didn't start out that way either but over time something happened to it...even though bias and dc balances all checked out ok. Hooking the Aleph 2's back up was like comming out of a smoke filled room..... I never could figure it out, don't know if the guy that bought em did either....
Overall the Aleph 2 is the most neutral of the Alephs and is certainly hard to beat. They take what ever the 12B4 throws at em and they don't get lost in doing so.
Mark
Overall the Aleph 2 is the most neutral of the Alephs and is certainly hard to beat. They take what ever the 12B4 throws at em and they don't get lost in doing so.
Mark
Hi guys,
Well I only listened to some jazz through A- X last night. Cymbals sounded very natural. I will give it some tougher music to handle tonight and see how the highs sound. I was very impressed last night after hooking up the sub. I think I have been pushing it too hard trying to get some decent low end out of it. With the sub taking care of that part the sound stage was quite nice.
I hope folks don't think I'm trying to take this thread off course. A few folks asked about a comparison between the Aleph and the Krell. I'm just trying my best to be fair in judging them. I have listened to the KSA50 clone a lot over the last couple of months. I have listened to the A-X very little because I didn't like the sound. It is such a drastic change with a sub added I want to give it another try. I will give it as much listening time as I can for the next few nights so I can give a better comparison.
Blessings, Terry
Well I only listened to some jazz through A- X last night. Cymbals sounded very natural. I will give it some tougher music to handle tonight and see how the highs sound. I was very impressed last night after hooking up the sub. I think I have been pushing it too hard trying to get some decent low end out of it. With the sub taking care of that part the sound stage was quite nice.
I hope folks don't think I'm trying to take this thread off course. A few folks asked about a comparison between the Aleph and the Krell. I'm just trying my best to be fair in judging them. I have listened to the KSA50 clone a lot over the last couple of months. I have listened to the A-X very little because I didn't like the sound. It is such a drastic change with a sub added I want to give it another try. I will give it as much listening time as I can for the next few nights so I can give a better comparison.
Blessings, Terry
speaking of pass stuff
Well, speaking of Pass stuff, I'm finishing my BOSOZ rebuild, putting together a X-CCS-BOSOZ with detached power supply.
I finally had the chance to test it with the Krell Clone, its working and sounded pretty good for the 20 min which I had time to connect it for. Hopefully it will meld well with the krell clone, but since its balanced probably not ideal. Wonder what kind of output impedance I have with 50K volume pots (connected on output)?
EDIT-- one more thing, its winter! The krell clone runs 4 degrees cooler now than it did in the summer. Get these things built quickly people!
Well, speaking of Pass stuff, I'm finishing my BOSOZ rebuild, putting together a X-CCS-BOSOZ with detached power supply.
I finally had the chance to test it with the Krell Clone, its working and sounded pretty good for the 20 min which I had time to connect it for. Hopefully it will meld well with the krell clone, but since its balanced probably not ideal. Wonder what kind of output impedance I have with 50K volume pots (connected on output)?
EDIT-- one more thing, its winter! The krell clone runs 4 degrees cooler now than it did in the summer. Get these things built quickly people!
AndrewT said:
Actually, the torch was to locate the + rail regulator heatsink through the ventilation grooves in the power supply case so that I could monitor its temperature with the chassis cover on. +50C so I guess I can expect +54 in the summer? Not bad since it drops 88 V to 60 V.
EDIT-
Yes, that is the PS and yes its a Par-metal; I believe its a series 20 but forget the exact details. click here for a high resolution picture of the inside of the PS.
in procrastinating from things I SHOULD be doing, I decided to visit diyaudio, which I haven't done in quite some time. I happened upon this thread...and I'm wondering, what chance does a n00b like me have at successfully building an amp like this? I remember Brian's GC GB and that seemed almost like a full kit, aside from the case, heatsink, connectors, switches, etc. I come from a computer background but have always wanted to build my own amp. With little EE knowledge, is this out of my league?
It'd be used for a pair of Dynaudio Contour S1.4's...I've been eyeing a Proceed HPA2 in addition to various McIntosh's, Conrad-Johnsons, Classe's, but due to a car accident last week, that'll be delayed for a while.
Thanks all...feel free to be blunt, I'd rather not get my hopes up and then have the innards of an amp taking up space in the basement for the next year
It'd be used for a pair of Dynaudio Contour S1.4's...I've been eyeing a Proceed HPA2 in addition to various McIntosh's, Conrad-Johnsons, Classe's, but due to a car accident last week, that'll be delayed for a while.
Thanks all...feel free to be blunt, I'd rather not get my hopes up and then have the innards of an amp taking up space in the basement for the next year
Hi Yoda,
with the help of this thread and the KSA50 Wiki, you should be able to build this amp. Give a read through the Wiki and see how you feel about it. It is not a tough amp to build and the boards are very straight forward. You need good heatsinking and a good power supply.
Blessings, Terry
with the help of this thread and the KSA50 Wiki, you should be able to build this amp. Give a read through the Wiki and see how you feel about it. It is not a tough amp to build and the boards are very straight forward. You need good heatsinking and a good power supply.
Blessings, Terry
yeah, I have both this thread and the wiki open right now. I'll read through that in its entirety later, but it seems okay for now...the biggest tool will be the diyaudio forums to help me through it.
Any idea when the next GB will be available? Lastly...aside from the case, switches and connectors that I use, what's a rough cost estimate of the amp+heatsinks? (I don't know how much heatsinks run, whereas I've bought the small accessories before)
Any idea when the next GB will be available? Lastly...aside from the case, switches and connectors that I use, what's a rough cost estimate of the amp+heatsinks? (I don't know how much heatsinks run, whereas I've bought the small accessories before)
You gotta love Mouser and Digi-Key. Ordered yesterday and they ship today... A few items are back ordered but should also be in this week.
Dear TROY;
Thank you for ordering from Mouser Electronics, Inc.!
Your order has been processed and will ship today.
The shipment tracker number is 1Z7759450308938829
==============================================
Thank you for your order! Digi-Key has processed and shipped
salesorder
#16549926, invoice #19428694, to you.
==============================================
Dear TROY;
Thank you for ordering from Mouser Electronics, Inc.!
Your order has been processed and will ship today.
The shipment tracker number is 1Z7759450308941137
Dear TROY;
Thank you for ordering from Mouser Electronics, Inc.!
Your order has been processed and will ship today.
The shipment tracker number is 1Z7759450308938829
==============================================
Thank you for your order! Digi-Key has processed and shipped
salesorder
#16549926, invoice #19428694, to you.
==============================================
Dear TROY;
Thank you for ordering from Mouser Electronics, Inc.!
Your order has been processed and will ship today.
The shipment tracker number is 1Z7759450308941137
EvilYoda said:
People here are very helpful, and the amp actually worked for me so that's saying a lot. If you have questions they will be answered and people that are smart have not stopped reading so that's good news.
speaking of being helpful, someone emailed me a question, by the time I read it I had no time to fully reply but will do so tonight or tomorrow. sorry.
EvilYoda said:
Go fan cooled!!! It will cut your cost, space and stress dramatically.
As you would expect, I didn't. I'm still in the process of making BIG passive cooled amps. I "thought" I didn't want the fan noise, but have since learned that proper design can hide that. (Linn Klimax, original KSA-50, etc..)