rickcr42
Fully Modded
Rest in peace my good friend.
Posts: 4,514
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Post by rickcr42 on Sept 20, 2006 23:48:39 GMT
works for me
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Cuppa
<100
Sent me a GRADO got me banned
Boner fide member of the Canadian Goat deprecation society
Posts: 33
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Post by Cuppa on Sept 21, 2006 11:25:13 GMT
Wow, this has turned into the Uber amp discussion
Out of interest, all these mods to the mapletree - how much would it cost to do and how much would the total be in terms of parts + original unit + labour?
Just out of interest mind (although I do have money to burn maybe, as long as I keep it quite re the wife).
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Post by jelosno on Sept 21, 2006 12:46:15 GMT
Since last week Thursday I do have a second job. My wife gave birth to our son. At the moment I do consider being father for the first time a second job
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Post by jelosno on Sept 21, 2006 12:48:01 GMT
Will it be still better if I do ONLY listen with my Grados? From the price point compared to the 119DA it has to be better
Stefan
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Post by jelosno on Sept 21, 2006 12:53:58 GMT
If I still have the numbers right the EAR+ HD in kit form is USD 500, ready build USD 600. From there you can go totally nuts with parts. Most propably I will... Maybe you can ask Lloyd whether he can include something like the Sowters in the first place so you don't pay for the Hammond 119DAs which you MIGHT replace later. As I said: you can go further and further and..... Only limitation, if you will stay with the original chassis, is that most 'upgrade' parts will not fit into it. Building a new one should be easy though. No need to be on the super design side of things to sound good. Once my parts are all here I will do a list and make a plan. I hope. Stefan
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rickcr42
Fully Modded
Rest in peace my good friend.
Posts: 4,514
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Post by rickcr42 on Sept 21, 2006 23:40:53 GMT
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Post by jelosno on Oct 9, 2006 15:42:49 GMT
Below is an answer from Sowter regarding what they consider an upgrade for a Hammond 119DA that comes as standard with the EAR+ Good stuff??? Stefan -------------------------------------------- We can make a standard M6 output transformer to this spec using our custom service and it would need size "D" price £62.25 www.sowter.co.uk/acatalog/SOWTER_OUTPUT_TRANSFORMERS_25.html#a41Alternatively we could make a transformer with a 30% Mumetal core. Same size but price £75.93. www.sowter.co.uk/acatalog/SOWTER_SINGLE_ENDED_OUTPUT_17.html#a245In this case the max power at 30 Hz would be reduced to 6 Watts. The combination M6/Mumetal core works as follows. At mid and high frequencies all the flux in the transformer runs in the Mumetal part of the core because the permeability is much higher. Mumetal has extermely low distortion and works well at very low signal levels (-100 dB). At low frequencies/full power the Mumetal saturates and behaves like air so the M6 part of the core takes over. The transition is compleely seamless. This is a way of getting the best of both worlds....No problems with high power or very low power and greatly improved transients and mid/high frequencies.
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rickcr42
Fully Modded
Rest in peace my good friend.
Posts: 4,514
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Post by rickcr42 on Oct 9, 2006 21:53:43 GMT
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Post by jelosno on Oct 9, 2006 22:10:13 GMT
I take this as a YES considering the Sowter as an upgrade to the $ 25 Hammond 119DA Stefan
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Post by jelosno on Oct 9, 2006 22:24:26 GMT
He told me that he has replaced some Black Gate caps in the signal path of the HD 150 with Solens (forgot which Solens...).
If he is happy with those he will replace the BG in the EAR+ with them as well since they are the same price. Not the same size though...
Stefan
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Post by jelosno on Oct 9, 2006 22:27:15 GMT
Sowter would make them to that spec
Stefan
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rickcr42
Fully Modded
Rest in peace my good friend.
Posts: 4,514
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Post by rickcr42 on Oct 10, 2006 0:04:36 GMT
Fine if you are looking to drive low sensitivity cans like the Senns but for a Grado specific driver a non issue and in fact my personal opinion is an amp using a 12AX7/5751 front end can use some extra attenuation even though 600/8 is still pretty hefty unless a special design (see above sowter custom) you usually get shitty bass with a trafos used at or near its wattage rating so for instance a 10W trafos is commonly used for 1-2 watts,a twenty watter for an 8 Watt amp,etc.,unless the amp is as a tweeter only driver or the cans have a known bass hump which in the end cancels each out though not the best way to plan an amp When you see "600 ohm output" on a line amp you need to know the actual primary impedance of the trafos will depend on the TOTAL LOAD on its secondary so will be anything but without careful matchups (and probably why i like multitaps ) Also. At a guess the reason the Hammond even works with an output stage likely close to 1K in actual tube output impedance without losses is the 32 ohms and up expected load on the secondary which raises the primary impedance to an easier to drive range than the marginal 600 ohms which is a real bitch even for an SRPP output stage to drive
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Post by jelosno on Oct 10, 2006 10:08:58 GMT
I am a bit lost - again ;D The EAR+ data is: Headphone output impedance: 7 Ohms. Sensitivity: 0.3 V for 10 mW output. Output power: 100 mW the 119DA data is: 8 Ohm with 4 Ohm center tap (with solder lugs) Power: Rated at 12 watts T hat is 0.1 W through a 12W trafo. Should be allright then. What would happen if the 4 Ohm tap is used instead of th 8 Ohm one? IF a Sowter is used should it rather have a ratio of 1000:8 or any other? For the price difference between the 119DA and the Sowter there COULD be an audible difference. Just what will it sound like??? On the other hand the is there much of an influence of the iron used at 0.1 W and a 12W rated transformer? You see, I don't get the reas picture here Stefan
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Post by jelosno on Oct 10, 2006 12:45:31 GMT
My question to Lloyd Peppard: "So I modify that question a bit: If you could choose any ratio – here 600:8 (I think that price and availability do have some influence for choosing this) – for the optimum to drive of the 32 Ohm Grados, what would you choose." His answer: Good question about the OPTs on the Ear+. I was looking for a ratio close to the 600:8 when I was designing the Ear+ and originally tried a miniature 1200CT:8 version which worked well using the center tap but was lacking in low frequency response. When I found the 119DA my search was over. However, if one were to experiment further you would really have to do some theoretical work first. This is because: 1. Increasing the impedance ratio reduces the output voltage (the voltage ratio is the square root of the impedance ratio). But is also increases the impedance seen by the driving tube which should improve linearity (one would need to look at the characteristic curves and load lines for the output tube). It also should allow a greater voltage swing at the output before the transformer. How this offsets the reduction due to the higher turns ratio would have to be studied. 2. Decreasing the impedance ratio increases the output voltage (the voltage ratio is the square root of the impedance ratio). But is also decreases the impedance seen by the driving tube which will result in increased distortion (one would need to look at the characteristic curves and load lines for the output tube). It also would also permit a lesser voltage swing at the output before the transformer. How this offsets the increase in output voltage due to the higher turns ratio would have to be studied. Obviously 1. and 2. are just the converse of each other but it is good to keep both clearly in mind if you are experimenting. I don't imagine the 600:8 is optimum for as you have pointed out, it is what was available and was only close to what I thought would work in terms of providing the required output voltage while not loading down the tube when low impedance headphones were used. Another factor that enters in to the mix is the different headphone impedances produce a different loading effect on the tube (as reflected through the transformer) but also affect the power delivered (power out varies as the inverse of the headphone impedance). Then, on top of that, the headphones may have different sensitivity so could require less or more power for a desired sound level. If I were to blindly experiment with a different transformer, I would go to a lesser turns ratio if I were to use primarily high impedance phones and a greater ratio if low impedance phones were to be used. The requirements for the transformer are similar to those for any OPT: you need sufficient inductance in the primary to ensure good low frequency response, and you want to control the parasitic capacitance so as to not limit the high frequency response. There is no global feedback in the Ear+ so the transformer specs stand on their own. Also, the value of the output coupling capacitor must be chosen to yield a resonant frequency with the transformer inductance below the audible range. So the 33 uF may not be the right value for a different transformer. It would be undesirable to have to go with a larger capacitance due to the greater physical size involved--which would be the case if the inductance were less than the 119DA. The size of the 119DAs indicate a higher inductance than you would get from a smaller implementation even though the power rating is well over what is required. If you are discussing these issues on a forum or with others, feel free to pass on the above comments as they may help to clarify the issues involved. Regards, Lloyd I like this man for his quick and excellent service
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rickcr42
Fully Modded
Rest in peace my good friend.
Posts: 4,514
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Post by rickcr42 on Oct 11, 2006 0:03:22 GMT
Agreed.Don't know the man but seems comfortable in his own skin.I also am partial to the good Dr's common sense approach to audio over flash and hype which to be honest if he did would likely earn him more "chops" in certain circles where it is not how a thing sounds but how it looks and what fancy phrases tossed around that count. Actual balance controls in a high end amp ? ARE YOU FRIKKIN CRAZY ?!?!?! We ALL know they destroy the stereo image even though most of us mere mortals do not have dead nuts left/right hearing balance but so ? According to the high end the gear needs to be held to some standard of perfection even in an imperfect world where real humans needs "usable" over a pack mentality to be cool. I also wonder if the EAR (and other) designs have been exploited by the dishonest since it is noatable that where once every single schematic and kit build manual (full wiring diagrams) were posted for download,very brave BTW,they are now gone.My personal opinion is he would never have posted the details if there was a problem with a "hobbyist" building one of his designs for personal use but no man needs to compete with himself for what is already a smallish niche market and that there are sooo many with no honor who think nothing of copying anothers work for personal gain is not in question. My main beef with most "cloners" is they have zero clue how the thing they sell even works so those who try to shave a dollar or two by going to the copy and not the original source are FKD if something goes wrong or they have a question about the amp which is like bying a used car "as is". If it runs and runs for a while cool.If ut breaks you are on your own and out some loot................... Stefan : that is one nice post there man and not only answers a lot of questions but asks the right ones in such an honest above board way I must say I am impressed mightily-Kudos to Lloyd from the Rickmonster when you correspond with him again Looks like the only way to answer the questions asked is like most other things in audio that have several "answers" and that is to listen and compare.Where most usually screw up on this is "improving" something before they ever even get to know the thing they beleive to have made better and without a benchmark,a comparison how to know ? If you are cool with it you can be the "Crash Test Dummy" of the EAR+ and if so build the amp "honest" as designed.no mods other than Mapletree approved.Live with the amp,get to know the amp,play it with recording you know intimately and have listened to for years so you know what is actually GOOD. Once you get the flavor of the amp it is then time to start on the upgrade path but not all at once dude. One "improvement" at a time that again you listen to with known music to try and figure out if it is an improvement or not at which time you either keep the update if better or lose it and move on to the next one if not. One thing too remeber and this is essential information imparted from high on top of MT.Rick (no zip code yet,working on it ;D ) CHANGE is not neccessarily BETTER but the tendency is for humans to proclaim it so 9 out of 10 times so again you need to listen THROUGH the amp and not TO the amp and again over time to see if the novelty of "new" is just that,something different,or if in fact a true improvement. My method of equipment evaluation is : When i stop listening to the amp and start listening to the SONG, find I am tapping my toe in time and my ass squiggling around in the seat 'cause I want to DANCE DAMMIT then the piece of equipment is making MUSIC But if even after a long session i find i am still trying to listen to the amp,focusing on the electronics and not the jams,then it is not for me.I am a music lover first and if it don't get my groovin' then it ain't got no "soul" and if it has no sould then it is just a box of parts in a pretty wrapper I am the guy that always dances in the clubs,the guy that can't even walk to the "little boys room" get releif without dancing my way there,who plays air guitars even at 50 and want the music to hit me right in the nuts emotionally,not in the head where I need to think about it "Groovin'.........on a sunny afternoon............"
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Post by jelosno on Oct 11, 2006 9:50:40 GMT
Another one from Mr. Peppard:
Sure, why not try something different for the OPTs. I welcome the feedback on the results. Just remember though that if I had to get Hammond to design and build the 119 DA as a custom product, they would be $400 transformers. As an engineer, I never use price as a factor in evaluating what is best. I start with the specs then use my ears. Lloyd
THAAAAT IS IT ! ! !
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Post by jelosno on Oct 11, 2006 15:55:18 GMT
Now I am into the calculation thing. I will have to start from scratch since my numbers are all over the place and I have lost track. To go from a source point backwards I need the VERY ONE information: What is the perfect drivin force for Grados like the RS-1 I mean, how man mW and mA in what mix does the Grado eat best for optimum performance. ALSO in the technical papers of the EAR+ there is always the talk of a 32 Ohm load on the secondary side. Is that true? What is a combined load then? The 8 Ohm resitance from the OPT PLUS the 32 Ohm of the Grado? Stefan
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rickcr42
Fully Modded
Rest in peace my good friend.
Posts: 4,514
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Post by rickcr42 on Oct 11, 2006 17:22:10 GMT
only if the "actual" secondary impedance of the trafos were 8 ohms but is likely to be much lower that that. When a trafos is specced for a particular secondary load (say 8 ohms or 4 ohms) then the primary impedance figure will be as per the spec sheet but go above or beyond (like hooking up an 8 ohm speaker to a 16 ohm tap on a speaker output trafos) you change the actual impedance seen by the final stage tube. usually you can fudge a bit in small amounts either way but if you try to go too wide from spec the results are often either transformer overshoot and ringing (requiring a damping network-pain in the ass + audible many times) or reduced bandwidth. A damn lot of stuff comes into play on this and I am by no means an expert so I can only post on what combinations have worked for me so far so I too am intersted in the outcome of this having much experience with the Sowter 8655 and using low power speaker transformers for driving 32 ohms,experience using lione out transformers and Mic transformer,experience using IT coupling for power amps (Interstage transformer),experience using transformers as small line stage gain devices,line/bridging transformers as isolation boxes and transformers splitters for signal distribution but no way can i claim to have trtied all headphone coupling options ;D On my short list for the future is the Magnequest B7 (expensive sucker but at some point i just have to know dammit ) and maybe one of the Lundahls though I don't recall seeing one that has a low enough secondary impedance for headphone duties (other than very expensive/large speaker trafos)
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Post by jelosno on Oct 12, 2006 8:42:23 GMT
It is a OPT enigma! I found this a good read to start with. Pls consider I am a absolute newbie to the electronix nebula. It might bore you. www.radioremembered.org/outimp.htmI have also copied bits and pieces of other websites in a doc for my reference but I have not kept the URLs. is this data available somewhere - haven't found it on the Grado site. can it be calculated from the RS-1 data available. I mean if we look for THE Grado OPT there should be a good knowledge of what current and volatage we want the Grado to drive on the secondary side of OPTs. Stefan
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rickcr42
Fully Modded
Rest in peace my good friend.
Posts: 4,514
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Post by rickcr42 on Oct 12, 2006 13:56:56 GMT
heading out the door to work so no time but WILL get back to this when i get in hang tight................... .
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Post by jelosno on Oct 12, 2006 20:18:40 GMT
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Post by jelosno on Oct 12, 2006 22:01:57 GMT
...it is getting radical 'over there'...
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Post by jelosno on Oct 12, 2006 22:09:08 GMT
Also found this somewhere deep in headwize.com
Different story but might help. I just have to sort this all out tomorrow.. . past midnight now
ciao & good night Stefan
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rickcr42
Fully Modded
Rest in peace my good friend.
Posts: 4,514
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Post by rickcr42 on Oct 13, 2006 0:14:22 GMT
Just got in (another long ass day malmost 8PM here ) so will keep it short 1-interesting thread at Head-Fi but one that answers zero of your questions 2-A CCS on any part of the EAR would be a mistake unless you plan to use it with cans needing high gain 2-losing the cathode follower would be a VERY BAD IDEA.The reason for a tube to even be configured as a CF is output impedance which is lower at the cathode but will have zero or little gain so needs an additional gain stage fronting it ONLY if there is not enough gain to begin with (for Grados a straight CF would work well ). The only other ways to get reduced output impedance from an inherently high impedance device (the vacuum tube) would be to configure it as a MU Follower,to add an active CCS at the top (pentode based ) or in an SRPP configuration ALL which are not only audible in the implementation of but make the design a more complicated affair by far-no longer single ended (plus though some say it is) and the higher the imnpedance of the tube the higher the step down ratio (primary impedance must be very high which combined with a low secondary is big time stepping dude) must be which means usually a higher gain tube and when we go there it it is noise control taking precedence in the design. just like with any other SS equivelant there are driver stages and there are gain stages and you need to match the end use to the device.Grado cans need drive and at best X2 gain (+6dB) from ANY home based source and no more than +10dB with a portable device as the source. as a parting gift I leave you with this : www.siteswithstyle.com/VoltSecond/Foreplay_headphone/Foreplay_to_Headphones.htmlread the whole page-especially the power reqierements part
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rickcr42
Fully Modded
Rest in peace my good friend.
Posts: 4,514
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Post by rickcr42 on Oct 13, 2006 1:32:19 GMT
again let's look at the Sowter 8655 Primary impedance= 10K ohms How many single stage single ended cap coupled gain stage tube preamps can drive a 10K ohm input impedance amp without treble attenuation ? NOT MANY ! so you need to either have a very high impedance on the next stage (50-100K in Z),use a solid state buffer/impedance converter or add another tube stage and even then you are marginal at lower than 300 ohm loads unless it is either a Cathode Follower,Mu follower or SRPP (or YT/SS Hybrid) so just getting a stage to drive the 10K of the Sowter is a tall order unless the tube is already a great power driver Medium Mu Tubes-5687,ECC99,12BX7,12B4.6H30 etc but then what happens when we add the transformer ? VOLTAGE STEP DOWN The Sowter at 30-100 ohms (triple paralleled secondary windings) is 12:1 ! Kind of precludes a simple unity gain follower stage as your amp unless your source has serious output capabilities Move to the 100-250 ohm load on the secondary-two windings in parallel,those two in series with the third,step down ratio a milder 6:1 and finally the 250-600 ohm secondary load (senns to line level output-don't even think about 600 ohm AKGs with a "typical" headphone amp ),step down a mild 4:1 this tells us what ? That for headphones (or line driving) that require voltage drive a gain stage is a must but as the load impedance is lowered/secondary windings configured as the impedance is lowered and the output voltage is lowered the same overall gain of the first stage is dead on because of the trafos reducing it according to output configuration but ONLY if the first stage has enough (but not too much) to be on target with each position but ALSO only if the stage can drive a 10K ohm primary impedance without losses in frequency and why you either need to use two stages with each topology suited to duty or a single "super tube" like the WE417 or 5682 or 6C45C which provide both gain and drive.
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