pingu
Been here a while!
Reallising what has been taken on with the GB
Posts: 332
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Post by pingu on Sept 9, 2018 15:46:39 GMT
Hi all,
Re entry modded a new (ish) version of the can amp for a friend re the mods on here as advised by Mike The amp has the larger16va transformer and the new finned heatsinks fitted as standard. Any one any thoughts on bypassing the four psu caps, if so what value and type ........ Wima's? Also any advantage in changing to op amp, it’s got a NE 5532P fitted at the mo Your thoughts or advice would be appreciated Thanks Martin
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Post by PinkFloyd on Sept 10, 2018 9:27:29 GMT
AD843 singles on a single to dual Browndog sound lovely in the Heed Martin I happen to have the very thing
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pingu
Been here a while!
Reallising what has been taken on with the GB
Posts: 332
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Post by pingu on Sept 11, 2018 14:15:09 GMT
Have you got a price Mike and I’ll let him know. Trust there’s room for them without removing any of the caps, the circuit print is a bit frail around there especially on the led. Which is what I am renewing now. Take it not worth bypassing the psu caps tho? All the best Martin
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Post by PinkFloyd on Sept 11, 2018 19:23:12 GMT
Have you got a price Mike and I’ll let him know. Trust there’s room for them without removing any of the caps, the circuit print is a bit frail around there especially on the led. Which is what I am renewing now. Take it not worth bypassing the psu caps tho? All the best Martin There's just enough room to fit the AD843 on the browndog Martin (a perfect fit in fact) and the browndog is socketed so you can try other single chips in the future if you so wish. I personally loved the AD843 in the Heed. The Browndog adaptor cost about £3 and the AD843 are a tenner each = £23 (RS take £12 each for them including VAT uk.rs-online.com/web/p/operational-amplifiers/0427244/) so call it £20 Martin. The very best power resistors for the Heed are the Mills MRA5 non inductive / 5 watt / 100ohm they really DO make a major improvement, I recently modded a Heed Canamp and the owner was over the moon...... the Mills are a must have in the Heed..... here is the direct link: www.hificollective.co.uk/catalog/mra05285-100r-mra05-mills-resistor-p-8173.html If you've got the Heed with the finned heatsinks you can also fit the 12 watt / 100ohm Mills MRA12 resistors as there's more room..... the 10 watt MRA10 will give you more surface area which is always a good thing in a power resistor...... MRA12 here: www.hificollective.co.uk/content/res-m1265-100r-12w-mra12-mills-resistorYou can bypass the two big caps if you want to, what value have you fitted? All the best, Mike.
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pingu
Been here a while!
Reallising what has been taken on with the GB
Posts: 332
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Post by pingu on Sept 12, 2018 7:24:37 GMT
Hi Mike, Resists are the 12wat Mills already PSU caps are either 12000 or 15000uf but amp back at his house now and I can not remember what I fitted for him but any suggestions for bp caps appreciated, thanks. I’ll ask him if he wants the op amps, but sounds good to me. I wouldn’t mind a pair of the OPA11’s you have for my old LNH ha. Old old original kit from way back. So I’ll hang fire and hopefully get both together and save on postage for you. Thanks for the offer Mike I’ll get back to you asap All the best Martin
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pingu
Been here a while!
Reallising what has been taken on with the GB
Posts: 332
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Post by pingu on Sept 12, 2018 18:32:50 GMT
Mike follow up to above The PSU caps are12000uf CCPA’s Martin
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Post by PinkFloyd on Sept 12, 2018 20:57:55 GMT
Mike follow up to above The PSU caps are12000uf CCPA’s Martin I wouldn't fit a bypass cap Martin...... leave them as is. Mike.
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Post by PinkFloyd on Sept 13, 2018 9:57:23 GMT
Hi Mike, Resists are the 12wat Mills already PSU caps are either 12000 or 15000uf but amp back at his house now and I can not remember what I fitted for him but any suggestions for bp caps appreciated, thanks. I’ll ask him if he wants the op amps, but sounds good to me. I wouldn’t mind a pair of the OPA11’s you have for my old LNH ha. Old old original kit from way back. So I’ll hang fire and hopefully get both together and save on postage for you. Thanks for the offer Mike I’ll get back to you asap All the best Martin OPA 111?
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pingu
Been here a while!
Reallising what has been taken on with the GB
Posts: 332
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Post by pingu on Sept 13, 2018 15:41:15 GMT
Hi Mike, Yes I’ll take a couple of the 843’s on the brown dog for my friends heed canamp.. The OPA111bm were the opamps I thought you had on sale. I was going to use them in the old chaira ha, the two round opamps in metal cans on a converter. I seem to remember when you built one a while back you liked them and they fit the amp without mods I think.. Anyway if you have a pair set up for the JLH ha amp let me know the price and you can add it to the invoice All the best Martin
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Post by PinkFloyd on Sept 13, 2018 20:03:23 GMT
Hi Mike, Yes I’ll take a couple of the 843’s on the brown dog for my friends heed canamp.. The OPA111bm were the opamps I thought you had on sale. I was going to use them in the old chaira ha, the two round opamps in metal cans on a converter. I seem to remember when you built one a while back you liked them and they fit the amp without mods I think.. Anyway if you have a pair set up for the JLH ha amp let me know the price and you can add it to the invoice All the best Martin Hi Martin, I've sent you an invoice for the AD843 on Browndog. The only OPA111BM I have these days are singles (mounted onto DIP8 sockets) so you'd have to source a DIP8 single to dual adaptor, something like this: www.ebay.com/itm/Double-Single-DIP8-to-Single-DIP8-Dual-OP-Amp-Opamp-Socket-Gold-Plated-Converter-/172677868865The AD843 on Browndog is 100% ready to rock in the HEED, just plug it in and grin like a Cheshire cat mate...... All the best, Mike.
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pingu
Been here a while!
Reallising what has been taken on with the GB
Posts: 332
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Post by pingu on Sept 13, 2018 20:21:36 GMT
Hi Mike, Thanks sent you a payment. No worries about the OPA111BM it’ll be adapter on adapter on adapter so I’ll give it a miss, but if you have any reasonable uncounted amps I have a few dual to single sockets that I can mount a pair on. All the best Martin
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Post by PinkFloyd on Sept 14, 2018 19:34:41 GMT
Hi Mike, Thanks sent you a payment. No worries about the OPA111BM it’ll be adapter on adapter on adapter so I’ll give it a miss, but if you have any reasonable uncounted amps I have a few dual to single sockets that I can mount a pair on. All the best Martin Shipped this afternoon Martin / Royal Mail first class. I'll have a look through my opamps at the weekend, I'm sure there will be something that will fit the bill. Was this the one you were looking at? If so, that one was sold along with the Chiara amp I built.
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Post by PinkFloyd on Sept 14, 2018 19:37:46 GMT
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Post by PinkFloyd on Sept 14, 2018 19:46:33 GMT
Actually Martin......... you'd get an Audio GD Earth in the Chiara, I have one up for sale on ebay at the moment: www.ebay.co.uk/itm/Audio-GD-Earth-dual-discrete-opamp/173524731119I fitted an Audio GD sun into the Chiara and it sounded awesome: I have the "official" Audio GD Earth extension leads which are a bit too long IMO but you can shorten them to custom fit the chiara. Just an idea.
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Post by PinkFloyd on Sept 14, 2018 19:49:11 GMT
All this is getting me in the mood to build another amp
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pingu
Been here a while!
Reallising what has been taken on with the GB
Posts: 332
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Post by pingu on Sept 15, 2018 8:11:22 GMT
Hi Mike, Yes it was one of those in the first pix. I’ve tried the GD Audio bits in the amp but because it’s an original kit getting them in is a bit of a dogs breakfast.. Thanks for the quick shipping Mike I’ll let you know when it arrives All the best Martin
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pingu
Been here a while!
Reallising what has been taken on with the GB
Posts: 332
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Post by pingu on Sept 18, 2018 17:16:03 GMT
Hi Mike Thei 843’s have arrived and I’ve fitted them together with the new jack socket. Must say on first hearing I prefer the original but I’ll running them in for a day or so the let my friend decide. This is a first impression so no doubt it will change when they burn in. All the best Marin
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Post by PinkFloyd on Sept 18, 2018 18:44:43 GMT
Hi Mike Thei 843’s have arrived and I’ve fitted them together with the new jack socket. Must say on first hearing I prefer the original but I’ll running them in for a day or so the let my friend decide. This is a first impression so no doubt it will change when they burn in. All the best Marin Hi Martin, Give them a while and if you don't like them send them back and I'll refund you, no probs at all. What ones did he have in the HEED originally? ATB Mike.
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pingu
Been here a while!
Reallising what has been taken on with the GB
Posts: 332
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Post by pingu on Sept 18, 2018 20:30:19 GMT
Hi Mike, Ok I’ll t ell him but that was my opinion not his I’m sure he’ll be ok. He had the stock NE55xxi in there and to be honest I was surprised how good it was when u checked it. But thanks anyway All the best Martin
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Post by PinkFloyd on Sept 18, 2018 21:06:08 GMT
Just saying, if the AD843 doesn't fit the bill then send it back for a full refund Martin . No pair of ears are the same, they are as unique as fingerprints...... we all hear things "uniquely" / all depends on our unique set of ears. Give the AD-843 a couple of days in circuit...... if it still doesn't rock your boat then send it back and I'll refund you in full Mike.
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