Hi Morten, what a super nice offer! Thank you so much! I say yes 😀 To me it seems I can do the Accuphase, I already researched a little. They have the rectifier onboard, which makes it less complicated. I will pay for the postage costs. Do you have the full list of parts and instructions?
There's also the ACA Redux... https://www.diyaudio.com/community/threads/aca-redux.381346/
Nelson Brock is selling these as stereo pair kits... reduxkits.com
Nelson Brock is selling these as stereo pair kits... reduxkits.com
I hated desoldering too until I got a Hakko 301 on the advice of fellow DIYers. Best $275 spent this summer.:
https://www.amazon.com/American-HAKKO-Products-FR301-03-Desoldering/dp/B07BFVFMS9/ref=sr_1_1?crid=OS2T9OKJ4ONS&dib=eyJ2IjoiMSJ9.w3bRpgEuAZWs2zaIN2UeTm0Qth4LauvLo9dmVddjhpKoe_1BKVCPdqrkW1zI9Maqo39IjLjYkGTq5erOpvsnc3dx24WxjpZ0FzSXF3j9I3jcLcCAxGWfZr4demSsTjrxJxR3-3_3F6wmUEGGku75p3elZBk1dVXDaeuIB4VEmuHcwGMWO3RP92J0mEH3oaLU_kqMkta91GqeuaSVpnyQE_QH4PAK8FsF76snpjWb1LfY_3igXYWj7pf37KwXtGCauvpG2WrDoOsUFTI9EpvgxgJTbfegrl6dfDW4uKg8m9o.AQIODsgCgWrkN6rndkc3hzei48KemzNDEMPVS0nCMrE&dib_tag=se&keywords=hakko+301&qid=1728917319&sprefix=hakko+30,aps,213&sr=8-1&ufe=INHOUSE_INSTALLMENTS:US_IHI_5M_HARDLINES_AUTOMATED&th=1
And while you're at it, put a drop of solder on all of the SMD legs.
Last edited:
@_Bert_: It is in your best interests to step back right now and look at the larger pictures in play for good bass response.
First, your amp and speakers must be matched. The speaker needs to speak down to 30 cps and the amp has got to have enough power to drive the speakers sensitivity. As good as the ACA Class A is (got two of them and use them all the time) it will not drive the 89 dB sensitivity speakers you have.
Second, realize that the cost of a quality amp is in the case and power supplies -- particularly in the transformers and caps. This is the majority of the cost in the Aleph 30 I quoted to you (fully $900 of that 1200 figure). You can fudge to your heart's delight but you won't improve your bass response.
Third, your room determines a lot of the bass response you hear and REW provides the means to test this; but you will have to have a reasonably-accurate microphone and A/D converter.
Good bass response is expensive and while some kind DIYers will help you along (kudos mOrten) the costs are in the speakers first then the case/power supply of the amp.
Take it from me, Bert. Some smart decisions on your part at this stage will save you a lot of trouble and expense down the line.
First, your amp and speakers must be matched. The speaker needs to speak down to 30 cps and the amp has got to have enough power to drive the speakers sensitivity. As good as the ACA Class A is (got two of them and use them all the time) it will not drive the 89 dB sensitivity speakers you have.
Second, realize that the cost of a quality amp is in the case and power supplies -- particularly in the transformers and caps. This is the majority of the cost in the Aleph 30 I quoted to you (fully $900 of that 1200 figure). You can fudge to your heart's delight but you won't improve your bass response.
Third, your room determines a lot of the bass response you hear and REW provides the means to test this; but you will have to have a reasonably-accurate microphone and A/D converter.
Good bass response is expensive and while some kind DIYers will help you along (kudos mOrten) the costs are in the speakers first then the case/power supply of the amp.
Take it from me, Bert. Some smart decisions on your part at this stage will save you a lot of trouble and expense down the line.
My mono block ACA's worked fine with these small 2-way speakers (before I built the OBL-15):
http://www.troelsgravesen.dk/SBAcoustics-61-NAC.htm
It was the exact speakers shown as I purchased them from Troels Gravesen.
If the impedans curve does not have nasty low dips I think ACA can be fine with smaller mid-sensitive speakers if just normal listening level is required.
Those small speakers could play surprisingly good bass.
Another very simple and fun amp to build is the MoFo.
I still have by BA-2018 line stages. They wait for a suitable application.........
http://www.troelsgravesen.dk/SBAcoustics-61-NAC.htm
It was the exact speakers shown as I purchased them from Troels Gravesen.
If the impedans curve does not have nasty low dips I think ACA can be fine with smaller mid-sensitive speakers if just normal listening level is required.
Those small speakers could play surprisingly good bass.
Another very simple and fun amp to build is the MoFo.
I still have by BA-2018 line stages. They wait for a suitable application.........
Thanks, yes I agree with you that the ACA series are on the light side for me. Through the decades I bought some too light amps for the Magnats. What do you say about a Audiolab 8000P amplifier?
Cannot comment on the Audiolab as it is outside of my geographical area. It is certainly, however, in the right direction from where you are now. With 150 watts per channel it will drive your speakers to their capabilities -- which are modest in terms of bass extension -- as 50 hz only takes you down two and a third octaves below middle "C" and that assumes the specs are accurate -- frequently they are fudged with -3 and -6 dB falloffs. You would be better off around 30 cps for the low range of the speaker. Failing that you can use a subwoofer but they introduce a host of other problems.
Suggest the European DIYers on this site can speak to the Audiolab 8000p. But there is something I can offer you now.
The more power you get from an A/B amplifier, the more transistors are employed. This has the positive of more power but at the cost of less clarity. Nelson Pass is famous for his comments about "simpler is better" and a SEPP amplifier such as the Aleph is "Single Ended Push-Pull." More power than a true class A amp (the ACA at 10 watts per channel) but still single-ended for clarity. My Alephs max out at 37 watts RMS and have a high curent of +/- 22 volts from the PSU. They drive my Tekton Double Impact speakers silly but these are 98 dB sensitivity.
So the watts power number is a bit of a fallacy. Each doubling of the watt number gives you 3 dB more loudness. So a 240 watt amp is 9 dBs louder than a 30 watt amp. Viewed in this context, you need enough RMS power to drive a speaker into the low 100s and preferably around 105-110. Peaks are another question.
So your 89 dB speakers will require 32 watts of true RMS power to get to 105 dB. And this is an ideal number because the higher you go from here, the more transistors are required and clarity starts suffering. Suspect this is the reason so many audiophiles refer to the Aleph as the best amp they have ever heard.
Was not able to find the Audiolab's amp type but guess it is probably push-pull. The knowledgeable folks on this site can help you here.
Suggest the European DIYers on this site can speak to the Audiolab 8000p. But there is something I can offer you now.
The more power you get from an A/B amplifier, the more transistors are employed. This has the positive of more power but at the cost of less clarity. Nelson Pass is famous for his comments about "simpler is better" and a SEPP amplifier such as the Aleph is "Single Ended Push-Pull." More power than a true class A amp (the ACA at 10 watts per channel) but still single-ended for clarity. My Alephs max out at 37 watts RMS and have a high curent of +/- 22 volts from the PSU. They drive my Tekton Double Impact speakers silly but these are 98 dB sensitivity.
So the watts power number is a bit of a fallacy. Each doubling of the watt number gives you 3 dB more loudness. So a 240 watt amp is 9 dBs louder than a 30 watt amp. Viewed in this context, you need enough RMS power to drive a speaker into the low 100s and preferably around 105-110. Peaks are another question.
So your 89 dB speakers will require 32 watts of true RMS power to get to 105 dB. And this is an ideal number because the higher you go from here, the more transistors are required and clarity starts suffering. Suspect this is the reason so many audiophiles refer to the Aleph as the best amp they have ever heard.
Was not able to find the Audiolab's amp type but guess it is probably push-pull. The knowledgeable folks on this site can help you here.
Last edited:
Hi all
I recently bought and solder Ba2018 line stage , what is purpose of R23, C4 circuit ? A watched on pics of ready preamps that some people soldered them when using with KSC1845/992 combo and I recived schmatics with description not to solder them when using KSC1845/992 .
Is it possible to You guys set DC during regulation below 50mV - I ve got some fluctuations betwwen 20 and 80 mV ?
I recently bought and solder Ba2018 line stage , what is purpose of R23, C4 circuit ? A watched on pics of ready preamps that some people soldered them when using with KSC1845/992 combo and I recived schmatics with description not to solder them when using KSC1845/992 .
Is it possible to You guys set DC during regulation below 50mV - I ve got some fluctuations betwwen 20 and 80 mV ?
R23 C4 (R46 C9) is a compensation circuit needed with the TO-92 devices. It is not necessary with the TO-126.
Does your DC offset stabilize? If not, check your soldering and connections.
Does your DC offset stabilize? If not, check your soldering and connections.
6L6 thanks for quick response , I am little concerned but in manual there is exactly opposite statement
leave R23 C4 open means do not solder them ? there is mistake in documentation reciverd from shop ?
I will chceck my soldering !!!!
leave R23 C4 open means do not solder them ? there is mistake in documentation reciverd from shop ?
I will chceck my soldering !!!!
The large transistors are the “alternate output devices”. Depending on the age of your kit you have either KSC2690 and KSA1220 or Toshiba TTA004 and TTC004. The large transistor package is TO-126. The small package is TO-92.
Large output transistors are used if you intend to drive headphones.
If you choose to use the alternate devices, I.E., the large transistors, make the following changes -
R11 R12 (R32 R33) 15ohm and 400mW or larger dissipation.
C1 (C7) 5pF
Do not use R23 C4 (R46 C9) , leave empty.
Large output transistors are used if you intend to drive headphones.
If you choose to use the alternate devices, I.E., the large transistors, make the following changes -
R11 R12 (R32 R33) 15ohm and 400mW or larger dissipation.
C1 (C7) 5pF
Do not use R23 C4 (R46 C9) , leave empty.
Hi, I built the linestage, but its low frequencies are unsatisfactory for me. Has anyone had the same feeling?
@oloppolo : This is interesting because you are the second to suggest this recently.
Have just finished two BA2018 builds using the Premium method described above -- wherein the 2SK209s are matched and all the resistors are within 0.1% of spec. These two builds have gone into 2 stereo setups that are largely identical -- Pearl 3 Phono Stage to the BA2018 preamp to Aleph 30 monoblock (R Thatcher's design) to Tekton Double Impact speakers. Two completely different rooms, both fairly large and...
There is tremendous bass extension and accuracy. The second build, just finished, has a much better room for bass in general and, if anything, there is too much energy around the 30-60cps region.
Suggest you look at your build first, your speakers second, amp and cables third, and room fourth. The PCB design itself is high-end quality as regards frequency response and this is mentionned repeatedly by builders above.
Providing your system and room information here will also be of analytical help. Can you describe and picture your PCB build?
Have just finished two BA2018 builds using the Premium method described above -- wherein the 2SK209s are matched and all the resistors are within 0.1% of spec. These two builds have gone into 2 stereo setups that are largely identical -- Pearl 3 Phono Stage to the BA2018 preamp to Aleph 30 monoblock (R Thatcher's design) to Tekton Double Impact speakers. Two completely different rooms, both fairly large and...
There is tremendous bass extension and accuracy. The second build, just finished, has a much better room for bass in general and, if anything, there is too much energy around the 30-60cps region.
Suggest you look at your build first, your speakers second, amp and cables third, and room fourth. The PCB design itself is high-end quality as regards frequency response and this is mentionned repeatedly by builders above.
Providing your system and room information here will also be of analytical help. Can you describe and picture your PCB build?
Measurements can be a good thing.
It can be tested if the if the line stage has be expected voltage gain from 10 Hz to 20 kHz.
It can be tested if the if the line stage has be expected voltage gain from 10 Hz to 20 kHz.
Measurements are objective.
A lot of time can be wasted listening to something that are not fully tested before it is used in the system.
If no sinus generator is available "test CD's" can be streamed to be used instead. They have fixed frequencies, sweeps, phase test etc.
A lot of time can be wasted listening to something that are not fully tested before it is used in the system.
If no sinus generator is available "test CD's" can be streamed to be used instead. They have fixed frequencies, sweeps, phase test etc.