What High End PreAmp do you have?
- Thread starter elny
- Start date
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PabloTincho
Super Member
turnitdown
Well-worn member
It looks like you have a cap going bad.
I use my Luxman R117 into a Motorola PP 6BQ5 amp. Very sweet.
My Hammond nee Dynaco clone is on the bench for refurb.
I use my Luxman R117 into a Motorola PP 6BQ5 amp. Very sweet.
My Hammond nee Dynaco clone is on the bench for refurb.
It looks those top vent discs were struck with a semicircle crossed by a straight line. From a side angle it looks like pillowing on the disc. Its really apparent in some of the other pics that have more of a top-down view. I'm sure they're ok.
Pablo, see if you can get a side pic of one of those magenta capacitors. I'd like to see what series they are, because those don't look original.
Pablo, see if you can get a side pic of one of those magenta capacitors. I'd like to see what series they are, because those don't look original.
Bill Ferris
Lunatic Member
I guess my stable of preamps would fall in to the high end category ?
First the Mc. ones: both SS & tube units.
Mc. C 220 (Bedroom) In use every morning after wakeup
Mc. C 37 (Living room`s A/V rack for source selecting for distributing line level audio to 6 rooms stereo systems) has remained powered up 24/7/365 for several decades.
Mc. C 33 (Sunroom`s stereo) remains powered up 24/7/365 since installation 3 yrs. ago
Mc. C 32 (backup preamp to the Sunroom`s C 33)
Mc. C31V (Radio/computer room`s separates stereo system)
Mc. C27 (Spare)
Mc. C24 (Spare)
Mc. C22 (Original sixties built, and used when I switch over the Sunroom`s stereo system to total tube during cool weather)
Audio Note: M1 Phono (Spare tube preamp)
Lexicon DC 1, & CP 3 (Unused & leftover from nineties HT/surround setups)
Integra: DHC 40.2 A/V/P (Living room`s rack A/V system, but only HDMI audio is fed through it). in use every weekend evening.
The unused Mc. preamps : C24, 27, 32 were offered to me at very attractive & well below market value prices by various friends yrs. ago when they needed the money, so they have a sentimental value, and I don`t need the space or money to sell them, same with the Audio Note tube preamp.
Note: I can`t speak for any of these preamps of mine`s phono performance, as they are only used as line level source function, being I had to give up LP records in 11/19/81, due to a left side physical handicap situation.
All preamps function properly and have been trouble free, less some front panel replacement light bulbs & the C220`s original 12AX7 tube.
Ciao
First the Mc. ones: both SS & tube units.
Mc. C 220 (Bedroom) In use every morning after wakeup
Mc. C 37 (Living room`s A/V rack for source selecting for distributing line level audio to 6 rooms stereo systems) has remained powered up 24/7/365 for several decades.
Mc. C 33 (Sunroom`s stereo) remains powered up 24/7/365 since installation 3 yrs. ago
Mc. C 32 (backup preamp to the Sunroom`s C 33)
Mc. C31V (Radio/computer room`s separates stereo system)
Mc. C27 (Spare)
Mc. C24 (Spare)
Mc. C22 (Original sixties built, and used when I switch over the Sunroom`s stereo system to total tube during cool weather)
Audio Note: M1 Phono (Spare tube preamp)
Lexicon DC 1, & CP 3 (Unused & leftover from nineties HT/surround setups)
Integra: DHC 40.2 A/V/P (Living room`s rack A/V system, but only HDMI audio is fed through it). in use every weekend evening.
The unused Mc. preamps : C24, 27, 32 were offered to me at very attractive & well below market value prices by various friends yrs. ago when they needed the money, so they have a sentimental value, and I don`t need the space or money to sell them, same with the Audio Note tube preamp.
Note: I can`t speak for any of these preamps of mine`s phono performance, as they are only used as line level source function, being I had to give up LP records in 11/19/81, due to a left side physical handicap situation.
All preamps function properly and have been trouble free, less some front panel replacement light bulbs & the C220`s original 12AX7 tube.
Ciao
I enjoy making vintage hifi work with modern sources. I have a Hafler IRIS preamp that was considered high end back in the early 90s, but now I guess its not so special. After doing a complete cap replacement on it I think it sounds better than anything else in my house. Great phono section, excellent detail all around. I have it hooked to the audio outs on my Blu-ray player for CD music and USB drives, and I get sparkling clear sound with a lot of impact. I sent the HDMI output to my LG display, so the audio goes to the stereo. I really like watching movies and shows that way. It sounds at least as good as a typical home theater. If I can figure out how to move audio from an AppleTV to the Hafler I'll be able to stream music to it as well.
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I am not sure that cap is OK. More than one angle is shown in the pics.
Examples of very bad caps showing very little bulge on top, the subsequent post lists readings of all six caps in the picture:
https://audiokarma.org/forums/index...dead-is-it-fixable.659156/page-2#post-8801234
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Roger,
The caps in your picture have vent discs with two perfectly straight lines scored, perpendicular to each other. When those pillow up and you look at them from the side, it makes the straight line look like a semicircle, so you know that the vent disc is bulging upwards.
When you look at the score on Pablo's caps you're seeing what you think is a semicircle caused by a bulge, but if you look directly down at the top you'll see the vent scoring isn't two straight lines, its a semicircle crossed by a straight line. If you tilt the cap so that the semicircle curve apexes towards the viewer, it looks more like a straight line due to perspective. When the apex is turned away from the viewer, it exaggerates the bow and makes cap look pillowed.
This is another one of those "the dress is blue" things, I think. What would solve it? Maybe if Pablo put a straight edge on top of the big caps and took a shot to show any relief between the cap and the edge?
Boba you seem very willing to dismiss a possible problem in someone else's amp
You're saying it's an optical illusion. I disagree with you on that point, I think it is a bulge, and another AK'er (@turnitdown) noticed it too. But sure, a straight edge across the top of that cap is a good idea. All I am going for here is to bring it to the attention of the owner of the amp. @PabloTincho
Disregard the scoring, and look closely and compare the way light reflects off that 470uF cap (on the left) and its mate. The difference is subtle, but it is there.
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Roger, thats nonsense. I could just as easily say that you seem very willing to find something wrong in someone else's amp. I'm not going to bother with that here. I think there's no cause for alarm, but if you disagree, so be it. It doesn't mean I think less of you.
I'm sure more people will step up to agree, and some may actually agree with me. As I said, this is another blue dress issue. The difference is I'm not going to get worked up about it, are you?
Glad we're in agreement.
The reflection is the first thing I go by when I judge a vent cap in circuit. If there was a straight cross on the vent cap I would wholeheartedly agree* with you. However when I see the scoring changes appearance depending on the angle, time to look at all the visual info available.
* I should note that when I first started out, if I saw pillowing under similar circumstances I would buy replacement caps and then pull the originals and test them, only to find out that ESR and capacitance was perfect, and what I though was pillowing was simply how stamped vent relief crosses looked under certain lighting. Fortunately now most manufacturers score the metal instead of stamping their reliefs. Or at least, thats what I've noticed, ymmv.
Mr Creosote
Super Member
VTA SP14
Pio1980
AK Member
I use an in-circuit ESR checker to survey elyticaps that otherwise don't show visible signs of ESR.
I didn't know such a thing existed but I'm glad it does. What is the model?
Perreaux SA3 Dual Mono Class A
Pio1980
AK Member
There are several, mine may be NLA but worked very well. I have to dig it out and look.
