Santa Claus DIY Tube Amp

Hi screamgigi

Forum members in Mumbai are an active lot and meet frequently enough.

It wouild be our priviledge to be able to get a chance to audition your completed amp..

I would be Happy to co-ordinate.

One of us has a Cadence 20 Watt Class A Valve amp driving his Cadence speakers.

I guess your amp would be ideal to compare that with ?

Have a nice trip.

Yes...we would love hear your amp gigi-ji.

manek.

screamgigi schrieb:

Hello folks Thanks all for the wishes. Right now I am in China in a city called Shiyan 450km northwest of Wuhan in Hubei. I get back home on Dec 12th after a deserved break in BKK Wrist is ok now. But cant lift any heavy equipment. But hope to finish off by Xmas. Do we have some volunteer for audition? I can send it to Delhi/Banglore wherever. Thereafter it can make onward journey to other places. Neutral-ji You quote me as if I am Laloo-ji ! Just enjoy :)

Nice to be in China. They have great audio shows there. I would love to audition your amp in Chennai, but the community here is too small. So, it will be great if u will invite me over when I next visit Mumbai.

I am back from China. Spent a couple of days in Shenzen and went to the local electric town. They have a wide range of home-grown tube and SS stuff. The fit and finish is of very high order. They use exquisitely carved Aluminium and Bronze chassis and fitting. Considering the ridiculously low cost of the product, it makes me wonder if they cut corners on the component which actually matters on reproducing the sound. The limited auditions were inclusive and I would not really recommend them if Hi Fi is the goal.

I bought lots of small things like Binding Posts, Cables, Caps. I do this whenever in Far East. Electric Towns in Taipei, Seoul and Tokyo have some very interesting things which are impossible to find in India. They are usually of reasonable quality and cheap to buy.

SC Amp Progress:

Just today I received word from Shri Viren that the Main Power Transformer has been despatched. So we are ready to start building. My finger are having some problems described by doctors as "motor control" or whatever. We shall see later what that could mean

As an aside, Viren-ji is a lot nicer than what appears. I wont disclose the reason, but suffice to say that he is truly an asset to this forum.


Amp_Nut-ji,

Thanks for the offer. You are setting up our modest amplifier against very unfair competition ! I guess the SC Amp is limited by PO as compared to the Cadence Amp.

Neutral-ji,

I don't live in Mumbai. But I do know a nice person in Chennai with whom you can link up. He owns various audio classic such as QUAD II, Dynaco, Leak, Tannoy, Fisher etc. His picked up everything in Chennai and paid less that what you will pay for a Denon HT receiver for the entire collection. I will request him if he could meet you sometime.

Nice to know you're back in action, screamgigi-ji.
More to you for completing your amp by Xmas.
kamal

[quote="screamgigi"]SC Amp Progress:


As an aside, Viren-ji is a lot nicer than what appears. I wont disclose the reason, but suffice to say that he is truly an asset to this forum.
quote]

I would second that

K

I agree about Viren....nice bloke he is.

Manek.

Amp_Nut-ji, Thanks for the offer. You are setting up our modest amplifier against very unfair competition ! I guess the SC Amp is limited by PO as compared to the Cadence Amp.

I thought the Cadence was a 20 watt ( though running in Class A, I believe.

Hence Power Output would be similar, nah ?

Or am I missing something ?

Amp_nut

1) Cadence had a class A el34 based 20 watter
and
2) Another el34 based 36 watter one which runs in class A for the first 9 watts and switches to AB for the rest.

Manek.

Our output pair is 6L6G. Cadence uses EL34. Lets see a typical operating condition.

6L6G Single Valve Class A

Anode and Screen Voltage: 250 VDC
Anode + Screen Current : 75mA
Power Output: 6.5 watts
Power Dissipation: 18.75 watts


EL34 Single Valve Class A

Anode and Screen Voltage: 250 VDC
Anode + Screen Current : 75mA
Power Output: 9 watts
Power Dissipation: 18.75 watts

The above ratings are for single valve. Double the Power Out for a Push Pull pair.


Note that 6L6G has a max Power Dissipation of 19 watts, whereas EL34 can safely dissipate 25 watts. So at this Operating condition 6L6G is almost maxed out, while EL34 is dissipating just about 75% and running cool. EL34 is beefier at this stage and has more grunt at its disposal. Therefore, if pushed to the brink our DIY Amp will run out of steam much before the Cadence Amp.

As per Manek-ji Cadence has two different EL34 models. I would guess the op-conditions would be something like this:


360 VDC at 63~67ma for the model which runs Class A all the way. Expect around 18 watts

420 VDC at 48~55ma for the model which runs Class A some way and then switches to Class AB. Expect first 6~8 watts in Class A and then approx 36 watts in Class AB. IMHO this is the preferred method of running a Valve amp and for our DIY Amp we shall employ this Biasing strategy.

cool s-gigi....sounds good.

manek.

Thanks screamgigi-ji for your very detailed explanation. I am lapping it all up.

Subjectively, how does the sound of the 6L6G compare to that of the EL34 ?

Also, could you throw some light on your choice of the 6L6G instead of the EL34 ?

Thanks

screamgigi,

correct me if I am wrong but wouldnt the 6L6G broadly sound kind of similar to a KT66 ? if so I have heard KT66 and liked what I heard.

Manek.

Amp_Nut-ji

You are so wickedly setting up the scene for a potentially dhishum dhishum situation

Yes its purely subjective and personal. I think in one of the posts we discussed the rationale for selecting 6L6-G. Both EL34 and 6L6G are great audio tubes. Some of the best classic amp had one of these as output pair. Its truly difficult to describe the sound. I find EL34 has more grunt and a slight upfront mid. You may say coloured. 6L6G is a well-rounded tube and sounds particularly nice in triode connected SE operation. For last many years my personal preference have been the 6L6G.

Manek-ji.

Yes KT66 belongs to the 6L6 family but slightly different ratings. KT66 can take far higher voltages and its curve does not slope so steeply as that of 6L6G. You can safely put a KT66 in any application which calls for 6L6. For the other way round you need to check the voltages. In my QUAD II, I use 6L6G in place of KT66 and like the result.

Please note I like the older coke bottle shape 6L6G. Other 6L6 variants may not be as good as that one.

You are so wickedly setting up the scene for a potentially dhishum dhishum situation

Not AT ALL my intention.

Apologies if I have unwittingly done this.

To date I have heard only KT-88s ( Liked), EL-34s ( did not like at all) and 845s (Loved ! ). To me, it seems that the each of the above 3 output valves have their own flavour !

Hence my question.

NO offence or provocation intended.

Ha haa Amp_Nut-Ji,

Itni jaldi maidan se bhaag gaye huzoor

That asides, my experience is exactly like yours. KT88 is ok, EL34 tolerable, 845 to die for (literally ) and KT66/6L6/807 to live for.

I am sure you will like the signature of our 6L6G amp.

screamgigi wrote:

Itni jaldi maidan se bhaag gaye huzoor

screamgigi-ji... Aap Ke Post Mere Liyea, Maidan Nahee.... CLASSROOM hai !

Aap mere Valve Guruji Hai !

screamgigi schrieb:

Neutral-ji, I don't live in Mumbai. But I do know a nice person in Chennai with whom you can link up. He owns various audio classic such as QUAD II, Dynaco, Leak, Tannoy, Fisher etc. His picked up everything in Chennai and paid less that what you will pay for a Denon HT receiver for the entire collection. I will request him if he could meet you sometime.

Then, are you a Pune-dweller? I would be glad to meet up with your friend. (Chennai is an audio desert where I thirst for audiophiles to meet.) I definitely don't look down on old audio equipment any more. My only audio friend here has 25 yr old DIY speakers on which I am currently listening to the great Latino singer - Connie Francis. If you can arrange a Christmas meeting, that will be your 'Santa Claus' gift to me

screamgigi schrieb:

Ha haa Amp_Nut-Ji, Itni jaldi maidan se bhaag gaye huzoor That asides, my experience is exactly like yours. KT88 is ok, EL34 tolerable, 845 to die for (literally ) and KT66/6L6/807 to live for. I am sure you will like the signature of our 6L6G amp.

For the benefit of all us SS guys, could you please tell us what u think of devices within transistors: bipolar, Mosfet, and IC. Also your views on switching amps and class D.

If I replace my Pulz 60W power amp with your amp, what change in sound am I likely to experience? And in which kinds of music?

screamgigi-ji

Last week I had a Conrad Johnson Pre-Power combo over at my place.

The Power Amp used 6550A Output tubes... 2 per channel and the Power Amp was rated at 70 Watts per channel.

Can you please share your opinion on the 6550 tubes ?

Are they more powerful than the KT 88 ?

Their characteristic sound ?

Are they Drop-In replacements for the KT-88s ?

Fortunately for me the CJ had GE Tubes throughout ( probably NOS ? )

The Tubes Sounded ( to my ears ) Better than the Chinese KT88s or the EH KT-88s that I have.

Amp_Nut schrieb:

screamgigi-ji Last week I had a Conrad Johnson Pre-Power combo over at my place. The Power Amp used 6550A Output tubes... 2 per channel and the Power Amp was rated at 70 Watts per channel. Can you please share your opinion on the 6550 tubes ?

Don't know where Screamgigi is but if you do not mind, I can share some of my thoughts on these 2 tubes having had some experience w/ them:

The 6550 is the American cousin to the British KT88 tube. Usually, they are suggested to be direct substitutes for each other (as is the case in my Jolida amp). However, their electrical ratings are different in triode, u-l & pentode configs with the higher ratings going to the British-origin KT88: the KT88 can handle 800V plate voltage while the 6550 can handle 600V in u-l mode & 450V in triode connection. Thus, the KT88 is capable of 42W/tube while the 6550 was capable of 35W/tube.

The KT88 was 1st introduced by MO Valve Co/GEC in Nov 1956 & it has its origins in the GEC TT21 & TT22 RF transmitter beam power tubes. The origins of the 6550 seem to be rooted in the American 6L6 tube. It was 1st introduced by Tung-Sol in 1965.
Not to be out-done, an improved 6550 was introduced by the MO Valve Co/GEC by the name of KT66 (used in the famous Quad II amps).

The KT88 is said to be a real pentode tube while the 6550 is said to be a beam tetrode tube. Both tubes are often characterized to have "clean, bright, sharp, punchy" sound. (in comparison triodes are often said to have "smooth, sweet, mellow, natural" sound). However, my experience shows that biasing the tube has a large effect on the overall sound (what a surprise! ). So, the 6550 in the Jolida were anything but "clean, bright, sharp, punchy" to my ears! I swapped them out for E-H KT88, which do give me a "clean, bright, sharp, punchy" sound. From my limited experience the E-H KT88 is better suited to this amp.
Au contraire, the 6550 used in Convergent Audio's JL2 has "clean, bright, sharp, punchy" sound. I've not looked at the CAT circuit but I bet that it is a different bias point & almost willing to wager that it is not ultra-linear! In fact, if memory serves me correctly, it is biased in class-A for the entire 100W/ch.

Both the KT88 & 6550 are often used in the ultra-linear configuration for power amps. The term ultra-linear is also called "distributed load amplifier" wherein the sceen 2 of the tube is DC biased from each half of the primary such that the tap point is 43% of the turns ratio or 18.5% of the impedance when measured from the primary center-tap. The tonality of the KT88/6550 ultra-linear amp is midway between a triode & a pentode amp. Technically speaking the ultra-linear amp delivers ~2X the power of a triode amp & about 75% of the power if the same tubes were used as pentodes using the same DC voltages with substantially less distortion. It seems that both the KT88 & 6550 are physically made to be used as optimum ultra-linear tubes. Hence you see them widely in this configuration.

Amp_Nut schrieb:

Are they more powerful than the KT 88 ?

No, I think that the KT88 is capable of more output wattage. Not substantially more but somewhat more. For example the 6550 gave ~50W/ch & the KT88 give more like 55-60W/ch.

Amp_Nut schrieb:

Their characteristic sound ?

Both tubes are often characterized to have "clean, bright, sharp, punchy" sound. However, the circuit implementation & bias voltages often characterize the sound.

Amp_Nut schrieb:

Are they Drop-In replacements for the KT-88s ?

manuf often say that they are but the KT88 can handle higher plate voltages.

Amp_Nut schrieb:

Fortunately for me the CJ had GE Tubes throughout ( probably NOS ? ) The Tubes Sounded ( to my ears ) Better than the Chinese KT88s or the EH KT-88s that I have.

I infer from your above comment that you compared the sound of the (NOS) GE tube in the CJ to that of the Chinese & E-H KT88 in your (Primaluna) amp. Did I infer wrong?
If I'm correct then, this is not a correct comparison. You should stick the (NOS) GE in your amp & compare & contrast. Or, stick your Chinese, E-H tubes into the CJ & compare. Otherwise the comparison is "dangerous" - I've found that each tube amp favours a select set of tubes over & above the wide selection available in the market. This, IMHO, has to do w/ the internal design & bias voltages chosen by the designer. Hence certain tubes will be biased near their optimum/near optimum bias points for best sound. For eg, it is well-documented that the Jolida amp I have likes Svetlana KT88, E-H KT88 & Svetlana, Tung-Sol re-issue 6550 tubes the best. Most of the other tubes do not sound as good in it.
Similarly the CJ might like the NOS GE the best. An expensive proposition & one that needs to be considered as part of the total amp purchase.

Hi Bombaywalla,

THANKS for am Extremely informative and well written post.

I agree with you on all counts.

What intregues me is that the CJ Power Amp ( Premier 11) uses 2 x 6550A per channel, and is rated at 70 Watts per channel. I thought that even the KT88s would be pressed hard to deliver that kind of power.. just about delivering it.. so was wondering how the 6550As can pull that off.

On the sound and biasing, I agree with you 100%. The CJ sound is not up my street, and given my preference for Rock music, I prefer the 'Classic KT88 UL' sound.

With my tubes in the CJ, the sound still had the CJ character.... the biasing and ofcourse the overall 'voicing' by CJ

Ofcourse the GE 6550s in my amp gave me the ideal sound. Any idea how much they cost in the US ? Will have to add them to my shopping list when abroad...

Thanks once again for your very detailed and informative response.

Cheers

P.S: The Conrad Johnsons are : the Premier 11 Power Amp and PV-12 Pre combo, fitted with GE tubes throughout. Surprisingly, the owner listens to Hard Rock with B&W speakers & this amplification !

PPS: The units came to my place with about a 1 inch carpet of dust inside.. but worked flawlessly. So much for being concerned about dust killing the units. Incidentally, These are 16 years old.

Amp_Nut schrieb:

Hi Bombaywalla, THANKS for am Extremely informative and well written post.

Thanx, Amp_Nut. Glad to read that the info was useful to you. It helped me jog back my memory re. these 2 very popular tubes.

Amp_Nut schrieb:

I agree with you on all counts.

Thanx again!
(we do have a rare event in audio - 2 audiophiles have actually agreed & it's in writing!! )

Amp_Nut schrieb:

Any idea how much they cost in the US ? Will have to add them to my shopping list when abroad...

This should give you a fair idea:-
http://search-comple...catZQ2d1QQsofocusZbs

if you are not an Ebay member you will not be able to access this page. In that case, I see prices varying all over the map: from $265 for a NOS matched quad (4 tubes) to $40 for a matched pair.

Amp_Nut schrieb:

P.S: The Conrad Johnsons are : the Premier 11 Power Amp and PV-12 Pre combo, fitted with GE tubes throughout. Surprisingly, the owner listens to Hard Rock with B&W speakers & this amplification !

yeah, exclamation point needed. The Premier 11 is a classic CJ product liked by many but it has the traditional/old CJ sound - soft, mellow & with a golden tube haze over everything played thru it. Yuck!
I cannot imagine how Hard rock would sound thru it? soft rock?....
Now, I have heard a more recent CJ 16L2 Mk2 preamp. Absolutely SUPERB! I had to ask myself several times "is this really a CJ? or, is it merely a CJ chassis?
what a preamp - served the music perfectly IMO. Great imaging, tonality, soundstage depth & height, bass, details, PRaT to name a few characteristics.

Amp_Nut schrieb:

PPS: The units came to my place with about a 1 inch carpet of dust inside.. but worked flawlessly. So much for being concerned about dust killing the units. Incidentally, These are 16 years old.

maybe the dust was working like an insulation barrier holding up components that would have shorted out by now!!
anyway, dust can be benefitial or harmful esp if there are some metal chips in it that get swept off the carpet. Those can do nasty things inside an electrical ckt. Tell the owner to get his vacuum cleaner out & suck up the dust FWIW.

yeah, exclamation point needed. The Premier 11 is a classic CJ product liked by many but it has the traditional/old CJ sound - soft, mellow & with a golden tube haze over everything played thru it. Yuck!

Yes, Exactly, that is why I had put that comment. To my ears, and my liking, my Prima Luna slamed the CJ pair. But I must add that there was something the CJ brought to the table (besides its name ) in terms of mid bass body. Though not my cup of yea, I can see a classical buff liking the sound.

The owner says that he likes the CJs because they are 'Never Harsh, or irritating " ....

I have heard a more recent CJ 16L2 Mk2 preamp. Absolutely SUPERB! I had to ask myself several times "is this really a CJ? or, is it merely a CJ chassis?

Yes, that is what they say about the recent CJs.

A month ago, I had the chance to listen to the CJ ACT-2 Pre at the Cadence factory. It did not seem to have the 'classic' CJ sound, but then the Entire system had components that I was not familiar with ...

The price variations in the GE 6550As seems WIDE

Hope I get a decent deal in Singapore when I go there in June 07.

Anyone knows if Tubes are available in Dubai at a decent price ? ( I will be there in early March )

Where ?

Ok folks. After an enforced hiatus we are back in business. We now have 99% of things needed to start assembly. Some pics.

First up. The chassis in black stove enameled. We need to drill out holes for Transformer mountings, and holes for the Speaker Binding posts and Line in connection. A cut out for power transformer is already made. So is the cut out in the rear to take the IEC fused and Switched socket.

In the front we need to drill a 9mm hole to take out the Volume pot shaft. The front fascia will be made of wood which will be engraved in laser. Suggestions are welcome to what should be written on the front.

Once all the holes are drilled out a coat of paint shall be applied before final assembly.

This is how its going to look like. SILK Output Transformers, DELTS Power transfomers and Choke.

The tube that we gonna use. RCA 6L6, RCA 6SL7 and Mullard 6SN7’s. Of-course we shall be ‘rolling’ the tubes later. But these are premium tubes and should be excellent for our use.

Some assorted riff raffs. Nothing exotic. NOS Carbon Resistors, Cheap and cheerful gold brushed bindings posts/RCA sockets, IEC Switched and Fused power socket, a small toggle to switch from UL to Triode mode, octal socket, etc.

Since Bombaywalla-ji wanted control on the NFB loop, we shall use this high quality rotary switch to do that. Between 0db (no NFB) to 20dB we shall have 6 steps. Enough I guess to meet all tastes and match 99% of speakers out there.

Tools of the trade. This modest dabba contains all the tool that we need to make our little amp

A special word of thanks and appreciation for Shri Viren here. He got the excellent DELTA transformer custom made and shipped to me for free. Till now he has very modestly refused to accept payment for the same. In his words this is his contribution to this DIY effort. I take the opportunity to applaud him and hope that I am soon able to reciprocate in kind.

That transformer is made beautifully. I measured the impendence and it is less than 20ohms, which is excellent by all account for the cost. I expect this will result in a superbly regulated PSU for our amp. Thanks Viren-ji.

screamgigi schrieb:

Some assorted riff raffs. Nothing exotic. NOS Carbon Resistors, Cheap and cheerful gold brushed bindings posts/RCA sockets, IEC Switched and Fused power socket, a small toggle to switch from UL to Triode mode, octal socket, etc.

Hi Screamgigi,
looking good!
I suppose that WIMA cap will be used in the power supply?

screamgigi schrieb:

Since Bombaywalla-ji wanted control on the NFB loop, we shall use this high quality rotary switch to do that. Between 0db (no NFB) to 20dB we shall have 6 steps. Enough I guess to meet all tastes and match 99% of speakers out there.

great!
NFB to suit the user.
Just curious, who makes this fine rotary switch?

bombaywalla schrieb:

screamgigi schrieb: Since Bombaywalla-ji wanted control on the NFB loop, we shall use this high quality rotary switch to do that. Between 0db (no NFB) to 20dB we shall have 6 steps. Enough I guess to meet all tastes and match 99% of speakers out there. great! NFB to suit the user. Just curious, who makes this fine rotary switch?

Looks like the OEN rotary swicth i have in my amp...

Thisis looking like a great project.
Kudos to Screamgigi and Viren.

Can't wait to see the finished product.

lovely !

How about actually calling it "munna" ! after all it started out being called munna amp. I'm begining to like the name.

Manek

bombaywalla-ji
The WIMA capacitors are for the PSU bypass and for the Phase Splitter section. They are nice, sturdy and don’t cost a lot. Exactly what we like

That Rotary Switch was earlier used in my linestage. It’s made of plastic and fibre and I had the contacts gold plated. It was just waiting for a project.

Savyasaachi-ji
I don’t think its made by OEN as I bought it from Korea. Specially made for audio.

Manek-ji.
Lage raho

gigi,
How about "Taansen" ?

Manek

Manek schrieb:

gigi, How about "Taansen" ? Manek

Manek Dikra,
I'm impressed...so what you are suggesting is that all further amps developed by Screamji be named after great Indian musicians, ala Audio Analogue.

So Taansen,Amir Khusrau...and the way down to Himesh Reshamiya

Cheers
K

well Krish....

I am going to impress you some more !

How about "Bhimsen"

Himesh Reshanmiya....hmmm interesting name maybe for an amp with nordic roots that we both love

On a more serious note....I would love the name "ella" on the amp. And I am sure this amp will "Sing". Gigi will make sure of that

regards,

Manek.

I second "Ella"...

screamgigi schrieb:

bombaywalla-ji That Rotary Switch was earlier used in my linestage. It’s made of plastic and fibre and I had the contacts gold plated. It was just waiting for a project. Savyasaachi-ji I don’t think its made by OEN as I bought it from Korea. Specially made for audio.

hmmm..tahnks for that sreamgigiji,
But i could swear that the OEn that i have (also a 2pole 6 way) looks exactly like the one pictured.

Guess the OEN guys copied the design or something..

Talking of musical names, how about Samanta Fox-ji

She did release an album or two back in 80’s. Always an uplifting experience watching her perform. In fact you could switch off the volume of your TV and just watch her. Such was her musical prowess

Update:

We are ready to assemble this Sunday. Hopefully by the end of the day we shall be listening to some music

Chassis is now drilled. Actually the task became quite an adventure. I had set aside 1st January (Sunday) for this. But the missus ruled that I needed to go out to her parent’s home for the customary New Year lunch. A happy compromise was quickly reached. I could take my drill m/c and markers to her folk’s home as along as I behaved myself. All I needed was to meet/greet others and then discreetly vanish into the back yard to do the deed. I fiendishly tried to pack my painting rig (including the 20lit compressor) also. But that was pushing the WAF to the limits. Thankfully, my daughter was able to smuggle in the Punch set in her kitty bag. God bless the child.

My wife’s folks are legendary hosts. That afternoon they had an exceptionally good selection of alcohol. Perhaps that can explain why nobody seemed to notice the noise later in the day when the base plate was being punched out.

So in the end everybody was happy. It was a nice day. Thankfully I live in a small town that allows me to lead my own type of lifestyle which peaks around winter. And anybody who has visited Jamshedpur knows its just great in winter. Clean environment. Great weather for outdoor activities, etc.

So a great day was to be had. Great activities with just the right amount of interaction with others. And you are happy in your own way.

This is the beauty of DIY

Savyasaachi schrieb:

screamgigi schrieb: bombaywalla-ji That Rotary Switch was earlier used in my linestage. It’s made of plastic and fibre and I had the contacts gold plated. It was just waiting for a project. Savyasaachi-ji I don’t think its made by OEN as I bought it from Korea. Specially made for audio. hmmm..tahnks for that sreamgigiji, But i could swear that the OEn that i have (also a 2pole 6 way) looks exactly like the one pictured. Guess the OEN guys copied the design or something..

They all look same. RS India too have something similar.

But I dont think stock this part is good for hi end audio.

heh heh...you sure can cut a deal

Cant wait to hear the amp !

Samantha ! now thats an artist(???)I havent set my eyes on for a while.....aunty sam always did lift those sagging spirits better than any other back then in college

Manek.

Manek schrieb:

Samantha ! now thats an artist(???)I havent set my eyes on for a while.....aunty sam always did lift those sagging spirits better than any other back then in college Manek.

Screamgigi schrieb:

Talking of musical names, how about Samanta Fox-ji She did release an album or two back in 80’s. Always an uplifting experience watching her perform. In fact you could switch off the volume of your TV and just watch her. Such was her musical prowess

ROTFL! you guys just crack me up!!
when I read your resp comments I was laughing loudly & my wife was asking me why I was laughing!!
what to tell her now.......


Re. a name for the amp - how about something "exciting" like "Model T", which belies its simplicity in construction & circuit yet effectiveness in sonics.

screamgigi schrieb:

. And anybody who has visited Jamshedpur knows its just great in winter. Clean environment. Great weather for outdoor activities, etc.

ach! we were allunder the impression that you resided in Poona. Not so!
I met a fellow from Jamshedpur last month @ a friend's party. He used to live there many yrs ago & work @ the TATA facitlity in the IT group. Loved it is what he told me. They were members of some TATA-sponsored or TARA-owned club & they could have a good social life.
Never been there myself tho'.

Hi all !

Just wanted to let you folks know that i sat here the last 2 hours following your Thread from the very beginning to the (almost reached) end, enjoying some spanish red wine and the sound of Robert Plant, Alice in Chains, and Stone Temple Pilots out of my DIY KT-88 SEP-UL using that great Tung-Sol Reissue 6550 at the moment. And yes - it is a great tube, the best i've had in my Amp till now, leaving that Chinese KT100 from Sino and Valve Art way behind it. The EH KT90 sounds also quite good, but not as fine and differenced as the Tung-Sol.

Had some good laughs and could follow your deceisions quite well, especially that one about Sam Fox

As for the name: i'd go for Ella!

I wanted to try out the 6L6 & 6SN7 for long now, maybe i'll do that amp also in the very near future, which will then may be a present for my Dad which resides in Canada since about 6 years. The Project i've firstly planned for him would be a EL84 SEP using the EF86 as first stage, but there he would need better Speakers.

Kudos to screamgigi for that great step by step how-to and greets to all of you people in India or wherever you may be.

Now i'm eager to hear the result of that Project.


Markus

Hi Markus,

Thanks for your comments on the Tung-Sol Reissue 6550.

I heard the GE 6550 and loved them... so I suspect that the 6550 is the output tube for me, in my Prima Luna Prologue 2.

Markus-ji

we are like this onleee saar

Interesting comments on that TS 6550 re-issue. Is it produced by the same company that's bringing out the re-issue Mullards?
What are your operating points on the 6550?

Ever since Amp-Nut-ji dismissed our little Munna amp , I have been plotting to get even. Plan is to use 4 x 6550 per channel to pump out approx 200 RMS /channel in a monoblock build. Right now I simulating the OPT design to have it locally wound. It will be too big and expensive to import.

Therefore, your words on the TS reissue 6550 is encouraging and consistent with others posting in AA and elsewhere. How much did you pay for each 6550? It is now in my 'buy' list.