I though a few D amp fans might be intersted in this.
I received the new Helder version 2 Buffer yesterday and have hooked this up to my Helder 2020 mk 3 amp. In my case I used a NOS Phillips Miniwatt 12AU7 that I had on hand. So how does it sound.
In my system, wonderful, it gives a sweetness and smoothness to the sound that is quite obvious and especially so if the amp is being fed from an iPod. For the money it seems like an excellent addition.
In my case it is being fed by a separate 12V battery, I am not sure how it would go on an SMPS, but I don't feel that would be an ideal marriage , experience tells me SMPS and pre amps don't work that well together.
The board quality is pretty good, but not as good as the 2020 amps. In terms of mods I would likely tap off the signal before the output caps as it is going through the inputs on the 2020 anyway, so getting rid of one set of caps makes sense to me. Secondly the volume control is pretty basic and would be best replaced with say a 23 step type one and maybe the opamp could be changed for something better though in essence its fine.
Hope it helps.
I received the new Helder version 2 Buffer yesterday and have hooked this up to my Helder 2020 mk 3 amp. In my case I used a NOS Phillips Miniwatt 12AU7 that I had on hand. So how does it sound.
In my system, wonderful, it gives a sweetness and smoothness to the sound that is quite obvious and especially so if the amp is being fed from an iPod. For the money it seems like an excellent addition.
In my case it is being fed by a separate 12V battery, I am not sure how it would go on an SMPS, but I don't feel that would be an ideal marriage , experience tells me SMPS and pre amps don't work that well together.
The board quality is pretty good, but not as good as the 2020 amps. In terms of mods I would likely tap off the signal before the output caps as it is going through the inputs on the 2020 anyway, so getting rid of one set of caps makes sense to me. Secondly the volume control is pretty basic and would be best replaced with say a 23 step type one and maybe the opamp could be changed for something better though in essence its fine.
Hope it helps.
Bummer, because I am planning to use a multi-output SMPS with the TA2020 amp I just purchased from Arjen. I was also considering the mk2 buffer to run off the SMPS.
Rhing the SMPS from Helder may well be fine for the buffer, I think it operates at a higher switching frequency than most, there are a lot of differences between SMPS units.
Overall I have just found that SMPSs tend to introduce a bit too much noise into pre amp stages and batteries have always sounded better, but I would certainly give the SPMS a try and see how it sounds.
The SMPS should be very good for the power amp.
Overall I have just found that SMPSs tend to introduce a bit too much noise into pre amp stages and batteries have always sounded better, but I would certainly give the SPMS a try and see how it sounds.
The SMPS should be very good for the power amp.
onis you need to control the volume from the buffer, you may indeed get clipping otherwise with std 2V sources, and in any case the idea of a buffer is to buffer just before the amp, with nothing in between.
The vol control on the buffer is 100k, its a pretty average one, can you simply replace it with the other vol control you have, I assume it is a better quality pot.
You could of course simply use the amps vol on full and control from the buffer, but this seems like a bit of a dodge and of course puts one extra part in the signal path.
The vol control on the buffer is 100k, its a pretty average one, can you simply replace it with the other vol control you have, I assume it is a better quality pot.
You could of course simply use the amps vol on full and control from the buffer, but this seems like a bit of a dodge and of course puts one extra part in the signal path.
the switching frequency is very high, well above 50 KHZ, so that noise is not an issue !!
I have now had some time to listen to the buffer and amp combined and must say it is a sweet combination.
One thing worth doing is to bypass the output caps on the buffer if it is only going to feed the standard amp module. Having done this I found the bass was improved and the whole set-up gained a little more detail.
A second thing which I will do is replace the vol pot, I have found it does not track perfectly on both channels and this leads to minor imbalances in stereo imaging, not surprising, it is just a basic pot and most of this type are not great. I will put a stepped 100k Dact style pot on instead in the next week.
I notice the price on the buffer has gone way up, but still a good buy I would say.
One thing worth doing is to bypass the output caps on the buffer if it is only going to feed the standard amp module. Having done this I found the bass was improved and the whole set-up gained a little more detail.
A second thing which I will do is replace the vol pot, I have found it does not track perfectly on both channels and this leads to minor imbalances in stereo imaging, not surprising, it is just a basic pot and most of this type are not great. I will put a stepped 100k Dact style pot on instead in the next week.
I notice the price on the buffer has gone way up, but still a good buy I would say.
the volume pot in the buffer amp is for best adjustment of both amplifiers combined. with this pot, the buffer amp can control distortion, when the connected audio source which delivers higher audio voltages. so, both volume controls are able to select a certain of wanted or unwanted kind of THD or soft clipping.
Loud pop on start-up
I followed this advice, and I get a very loud pop on start-up. In the eBay ad for the tube buffer, it states:
"Due to too much POP noise when starting the PREAMP, we have replaced the input capacitors to 2.2uf."
First of all, I thought the 2.2uF caps on the V2 buffer board were the output caps, not the input caps. Should I put the 2.2uF caps back in place?
I followed this advice, and I get a very loud pop on start-up. In the eBay ad for the tube buffer, it states:
"Due to too much POP noise when starting the PREAMP, we have replaced the input capacitors to 2.2uf."
First of all, I thought the 2.2uF caps on the V2 buffer board were the output caps, not the input caps. Should I put the 2.2uF caps back in place?
Hi Rich
The output caps are the large red ones, they can be removed if the buffer is feeding into a module that has input caps on it. You must have a cap somewhere either on the amp module or on the buffer.
Basically with both output and input caps in series you roll off the bass more.
I have no problems with big pops but there will always be a small pop, it was the input caps for the buffer they replaced with a smaller one, there is no need to replace that.
The output caps are the large red ones, they can be removed if the buffer is feeding into a module that has input caps on it. You must have a cap somewhere either on the amp module or on the buffer.
Basically with both output and input caps in series you roll off the bass more.
I have no problems with big pops but there will always be a small pop, it was the input caps for the buffer they replaced with a smaller one, there is no need to replace that.
I measured the DC voltage on my speaker outputs of my TA2020MkIII amp with the MkII tube buffer. On power up, I read -2.4V on both channels. It starts to decay to about +8mV in about 10-15 seconds. The first time I powered up, it sent the T-amp into fault mode. On second power up, I got the same surge, but the T-amp remained on. I can't make any adjustments on the DC bias pots to bring the DC as close as possible to 0mV. After the initial surge on the second power up, I plugged in some cheapie test speakers and I have decent sound out of both speakers. I am very concerned that I cannot use this product with my T-amp, which is a shame, because I really wanted to further improve the excellent sound quality I get from my T-amp.
I turned the amp off and I get the really loud pop too. Does anyone have any ideas on eleiminating/reducing this pop on turn on and turn off?
with this konfiguration I think it´s best to connect speakers after turned on and disconnect speakers before you are going to turn off the amp.
So let the amp always ON. It´s also better for receiving immediately best performance without any warm-up
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But another newbee question from me regarding the way from the cinch sockets of my CD Player to the V2 buffer amp:
how to handle with the black mass cable on the board which is shared from the right and left input together ? Cinch outputs have for each channel the separate mass contact and if I am not wrong it´s the outer ring which is mass, or ?
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