coop_301
The preamp or no preamp , powered preamp or passive preamp conversation has been discused more than once on Audiogons forums .
There is no right or wrong answer , unless as Tom pointed out if you have long interconnects then you need a powered preamp .
Think of it this way , if you are only using a DAC that has a volume control then go directly to the amp , why spend money on a preamp and another set of interconnects ? Spend your money on Upgrading the interconnects from your DAC to the amp , just my opinion .
Have fun reading 219 pages , lots of good info .
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coop_301 & unsound
The fun part about this forum is getting me and others to thinking about the subjects being discussed . Preamp or no preamp , unsound's technical explanation got me thinking again , do I need an active preamp ?
Asiaaudiosoc brought up a great point about the volume control , in my opinion it's the most important componet between your input devices and your amp . I heard the difference between a stock and high grade Alps , it wasn't subtle .
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Tom T & Tom D
Thank you for your guidance , now I don't have to agonize or worry about making a bad decision with inductor guage .
I had looked into the foil inductors after beetlemania's positive experience, but they are to large in diameter and they don't come in the smaller guages that are used on the Thiel crossovers .
As for resistors , I already have about $100 worth of Mills mainly because of having to parallel resistors to achieve value and wattage .
Moving the crossovers out of the speaker cabinet has interested me ever since I saw an Italian speaker for sale at Echo HiFi in Portland , this is was and is the only speaker that I've seen with external crossovers . I'm still wondering why this isn't more common on higher end speakers , but me doing it is just beyond my ambition and capability .
The simple and rewarding act of changing mounting screws has remotived me to start replacing componets on the crossover boards . Rob
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A while back Tom suggested trying to using brass fasteners .
I found the size for my 2.7 speakers to be 8/32 by 1/2 inch for the coaxial and by 1 inch for the woofer and radiator . The pan head srews fit perfectly in the woofer and radiator but were a little to large in diameter ( .6mm ) to fit into the coaxial .
After spending a lot of time looking for a 8/32 with a smaller head and being unsuccessful I had to grind down the head of the panhead screw .
For about $12 It was worth the effort .
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Thank You Tom T. & Tom D.
The fasteners/screws/bolts that held the speakers and radiator were made with ferrous metal those used on the speaker binding plate were not . I wonder why after your finding in 1978 that ferrous metal screws were still used ?
I hadn't thought of using nylon or delrin so looking into it I found that McMaster-Carr carries the reinforced nylon screws with the same size socket heads as the originals . part # 91221A445 1/2 inch for pk of 10 $8.64 and part # 91221A460 1 inch for pk of 10 $8.73 , so for about $45 you can have an easy upgrade !
The music sounds cleaner , I thought about how to discribe the improvement smoother or more definition but cleaner sounds good . It really showed when playing Dvorak " From the New World " symphony # 5 .
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Tom
It looks like another screw job by the New Thiel Audio ,
the screws/bolts were black steel on mine !
I still got a bargain and the only way I could afford the new ( repaired ? ) 2.7s but I never expected different wire, inductors and now screws .
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Tom D.
Wow , I'll say it again Wow , you are an amazing DIY'er .
There are some who don't believe that a fuse can make a difference , or a power cord or an outlet let alone going back to the breaker panel .
I've looked into Solen inductors but like the ERSE perfect lay they are to large of a diameter to use unless they are used standing on edge , I hesitate mixing inductor styles and manufactures . I'm still concidering increasing the guage of the 2 inductors on the woofer board . Rob
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And a Happy Father's Day to you jafant .
It was 6 years ago that I purchased a pair of CS2.7 speakers for a father's day gift to myself , today's gift to me is a pair of Clarity Purity 1uf 800v capacitors .
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pieper1973
I am using speaker cables I made for the negative and both ends of a pre-made for the positive . I used Cardas chassis wire to made the cables for both the pos and neg , while at first I like the extra slam they gave me over time I realized that they were harsh or grainy on the upper end so I repurposed them to be used on the negative side . The sound is fantastic compared to just the Cardas Neutral Reference alone .
You can check out an image , use Thiel as the tag and my system is about the last one .
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pieper1973
As long as they are or add up to the same gauge ,
I had tried using Cardas Quadlink as the negative , sounded good but not as dynamic .
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I was happy to hear that @thieliste 's speaker shootout declared the Cardas Clear Beyond speaker cables the winner being an owner of Cardas cabling . But for most the cost puts this out of reach for an average guy . While I tried and didn't succeed in using Cardas 9.5 awg ( the same used in the CCB ) in different configurations , parallel single runs , twisted and used as the negative with Cardas Neutral Reference used as the positive , I'm still always interested in speaker cable designs . The Cardas web site shows the Clear Beyond as a quad star but describes it as an octo star ? But at least they give you more information about cable designs and specs than most other manufactures .
Duelund conversion to DIY Helix Geometry Cabling after reading this thread I've become curious about this design , are any Thiel owners using or have tried this design ?
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dsper
I'll assume that you upgraded the Mains fuse with the Synergistic fuse ,
may I suggest that you replace the other 10 fuses with
Bussman or Littlefuse ceramic fuses ( $2.00 @ ) .
When working on my DNA-250 I replaced all the glass fuses with
the Bussman fuses and noticed an improvement well worth
the $22.00 . I purchased a Furutech fuse for the Mains
( 1/2 priced at $35.00 ) and compaired it to the Bussman ,
yes the Furutech sounded better
BUT not that much better than a $2.00 Bussman .
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dsper
From my experiences I am continually surprised ,
a fuse ! a resistor ! speaker placement change by 1/4 inch !
speaker wire gauge ( I resently doubled mine ) ! room acoustics !
power cord ! wall outlet ! TUBE ROLLING !!
You have a great system so keep trying to fill your glass
the fun never stops and the music just keeps getting better and better .
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thieliste
8 feet apart and 10 feet to you ,
if I recall that is what Tom said this is the spacing he used for testing his mods .
2.7 manual is 8ft apart and 8 to 10ft to listener , min 3 feet speaker center from side walls and 2 1/2 from front wall to rear of cabinet
toe in should be used only if you can't meet the min. to side wall spacing ,
I can't be 10 feet from the speakers , so I used the triangle formula of 8 x 10 x 10 this gave me an angle of just less than 48 degrees to the listener , my speakers are 84 inches apart and 104 inches to listening position , 37 inches to side walls and only 28.5 to the front wall .
So if you can sit further than 10 feet from the speakers you can experiment with moving the speakers more than 8 feet apart keeping the same angle to the listener
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Tom
After giving it some thought I was thinking the same thing about the pos/neg length differences and how they would affect the sign wave timing . Also after pricing out the wire I would want it became to expensive to consider trying as an experiment that may or may not work .
But reading about that cable design I discovered the Iconoclast cables designed by Galen Gareis a former Belden cable engineer , these cannot be DIY'ed . they have a similar design to the Alpha Goertz in that the positive and negative are laying flat one on top of the other . Not cheap but at under $1090 for 6 ft within reach .
Available from Blue Jeans Cable .
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Each polarity leg of an Iconoclast speaker cable is composed of twenty-four 24 AWG conductors. These conductors are twinned into Teflon®-insulated "bonded pairs," akin to those you may be accustomed to seeing in Belden's data cable products. These twelve bonded pairs are then braided in a basket-weave configuration and flattened to a rectangular profile. The two polarity legs are then laid back to back, and a nylon braid (red/black for ETP, blue/black or OFE or SPTPC) and FEP outer sheath complete the cable.
If you look up Iconoclast you can read the 61 pages of design theory , fascinating and educational .
The updated quad star design for RCA and Balanced interconnects sounds ( no pun intended ) very intriguing .
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Tom , beetle and pieper
Wouldn't upgrading the 2.4 value caps to Clarity CMR's be rewarding enough ?
duramax
I will be installing a Clarity CMR 1.5uf , a MR 8.2uf on and a Mundorf 68uf electrolytic on the woofer bd. I also got one of those for the tweeter bd. , If parts connextion has 8 Mundorfs in stock I will be replacing the 400uf topcon with 4 of the 100uf's on the mid bd. , Space is tight but I think I'll be using CMR 1uf on both the tweeter and mid boards as soon as they have another 20% off sale . I haven't found a small enough size electrolytic to replace the ERSE pulseX 15uf's .
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Beetle
Thanks , I haven't looked at Clarity's web site for a few months , I now see the PUR and I like the diameter size of the 1uf , So far it's not available at parts connexion .
David Garretson is the US distributor .
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shaundevuk
Tom Thiel and beetlemania worked together on upgrading
beetle's 2.4se speakers so you might contact them if you
are or would be concidering working on your speakers ,
again .
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1500 pair of 2.7s !
My speakers are #'s 329 & 330 , the prof's pair are around that #
and so far I haven't read of any serial #'s any higher from
Thiel owners responding on this thread .
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Tom
Thank you for passing on your information about speaker production #'s.
I am pleasantly suprised that there were 1500 pairs of 2.7s ,
way more than I thought .
Going back to internal wiring , after my trials and errors I totally agree
with you that the wiring inside the speakers have to be twisted .
While I can't say that the Cardas chassis wire sounds better than
the original Thiel 18 gauge solid wire ( beetle can and did ) ,
they do sound much better than the new Thiel 16 gauge stranded wire .
I've also change speaker wire configuration by using
Cardas Neutral Reference which is 4 X 11.5 gauge ( both polarities ) for the positive and using 2 X 9.5 gauge homemade for the negative ,
keeping them separate basically doubling the gauge input .
I haven't started yet on the crossovers except to buy the Mills resistors
from Partsconnexion because of the great sale price .
One big issue with the 2.7 crossover design when trying to upgrade
the components , to use Mills resistors one has to use 2 in parallel for almost everyone and for some reason they did not follow Jim's philosophy with limiting capacitors to 100uf .
When I replace the 400uf and the 330 + 220uf electrolytics on the
mid board because of space the best I can do is 2 X 200uf and
2 X 220uf + 1 X 110uf ( unless you recommend 2 X 200 and 1 X 150uf ).
Anyway upgrading speakers can be very challenging and I am very grateful for all your advise .
Thank You
Rob
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@beetlemania
I too replaced the posts with the Cardas rodium/silver with the gold plated nuts , a lot of work for little if any gain .
To clarify I replaced the new Thiel wire and made the assumption
that your 2.4se's came with Striaghtwire 18 guage solid wire ,
but either way the Cardas wiring was a big upgrade for both of us .
I used 17.5 awg for the tweeter and mid-range and 15.5awg for the woofer and to the inputs on the crossover boards .
I am curious about the new Straight wire configurations that Tom is experimenting with .
Did you use ERSE Fiol/Q for all 3 speakers ?
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@tmsrdg
ERSE sells direct erseaudio.com ,
I've also found that partsconnexion has the best prices when you wait for their sales and the best sellection for USA postage ,
HiFi collection is another great source but with higher postage rates .
@beetlemania
Thanks , I looked at images of 2.4 crossovers , interesting thing is that they all look like circut board material while I thought that Thiel was using a masonite type board like those used in my 2.7's .
But if you look at images of 2.7 you'll see that they look more like circuit board material and I think are demonstrator models .
What is your board material made of ?
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One Man's Dream - Ken Fritz Documentary
Great way to spend an hour on a Sunday morning .
The ulitmate DIY'er .
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johnhh
" what I wanted back then "
When getting back into listening to vinyl I tried to go back and build my dream system from the 80's all Carver electronics and all American
where posible . I had re-capped both the amp and pre-amp ,
installed new RCA connectors and speaker posts and yes they sounded better BUT they were still did not sound as good as I had dreamed of ,
or should I say they still were not up to modern sounding equipment .
I know there are now 199 pages in this thread but you'll find many good suggestions on amps that match well with Thiel speakers ,
good luck .
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Wow
10,000 posts ,
congradulations jafant you started one of the most followed thread
on audiogons forum !
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Tom
You mentioned the coils on the 2.4 not being as tight as original ,
after removing both mid/tweeter crossovers at the same time
I discovered that one has the original ERSE coil and the other has the newer version ( repair or that's all the new Thiel had on the shelf ? )
which is larger in physical diameter !
Does the larger coiling diameter offer better cooling ?
Question , both have been unwound about 5 inches to connect to a positive terminal , does the unwinding effect the inductor's performance? would it be better to connect a wire from the end of the coil to the positive terminal ?
Thanks
Rob
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@tomthiel
@duramax747 contact Tom PM , he's been of great assistance to me .
duramax, I am now going to wait for the PUR series for the 4 x 1uf caps needed for the tweeter/mid boards , they solve the size dilemma the I was agonizing over ,
as well as being an upgrade to the upgrade I was planning .
Still searching for an upgrade to the 15uf caps = in size to the ERSE pulse X caps
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theaudiotweak
I had experimanted with parallel wires outside and inside of the speaker,
I then went back and twisted the wires .
To me the parrallel wires externally were a little better sounding ,
but internally I found the twisted wires to be smoother sounding .
I had first twisted just the woofers wiring which increased the definition
of the lower frequencies , then I went back in and twisted the mid and
tweeter wiring which smoothed the topend harsness/grain .
The Sonoran Plateau wire looks very interesting and expensive .
Also the claim that when using their wire you should remove the insulation material sounds very unique . Plus drilling 4 large holes into the sealed upper chamber seems dangerous .
Rob
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To expand on my statement of interesting and dangerous ,
I had expereimented with steel ballbearings after reading a short article in The Absolute Sound using steel shot in a box placed on a DAC .
So using boxes out of wood I tried it on my Carver amp and heard an improvement , I also tried it on my CD palyer and it showed that placement was improtant as that over the power supply it showed a little but anywhere else created a slight degradation in sound .
I tried using the boxes on my McCormack amp and heard neither improvment or degradation .
So using wiring that incorporates steel balls might be an improvement or an expensive disaster IMO .
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prof
out of curiosity what 5751 tube are you using ?
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Tom T. & Duramax747
You got me rethinking the shunt circuit on the 2.7 , so I'm sticking with
the 220uf 6% ERSE and the 330uf 10% changing it from a Topmay ? %
to an ERSE , I was thinking 2 x 220uf 6% and 110uf 6% .
But I will be changing the 400uf ? % Topmay to 2 x 200uf 6% ERSEs .
I also ordered new 6 x 15uf 400V PulseX caps up from 250V .
Thanks again for all your insight .
Rob
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Tom Your information about erse coils is depressing and frustrating but on their website they state they are using CDA 101 and Solen states they are using ≥ 99.99 % Purity Annealed Copper. But so far these are the purest copper coils I can find , strange how Capacitors and wires are improving but not coils other than maybe foil coils over wire ones . Rob |
Thank You theaudiotweak Tom
Rob
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Thank You Tom T
Your knowledge and information keeps the Thiel legend alive
and looking towards the future .
So far only Rob's stock of ERSE coils ( which may or may not be 5-9s )
and Solen are the only 18 and 20awg coil available .
I've looked for the " new " Charity capacitors but have been not able to find any info yet , but no problem I'm still working on dimensions
and the fitting of the larger upgrading capacitors
on the crossover boards .
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Beetle
I have to ask , where any of the values on your resistors, capacitors
or inductors changed ?
When researching inductors of the same value both larger gauge wire
and foil both had less resistance .
As TT pointed out that those resistance changes would require
chnages on the crossovers .
The difference in ERSE 2.2mH 18 wg .781ohm and Solen's .76ohm
is small but it still has me concerned ( especially after TT's info ) .
Most likely I'll end up using ERSE and after TT's wire experiments
I'm going to install Cardas 18awg solid enamel coated wire , covering it with a cotton sleeve for the mid/tweeter speakers while keeping the Cardas stranded 15.5awg for the bass .
This turned into a more complicated project than I hoped .
Rob |
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pieper
have you tried Partsconnexion ?
they list that they are in stock .
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pieper
partsconnexion says that the resistors are a few weeks out if you can wait ,
I had to contact about purchasing 8 Mundorf electrolytic capacitors , so I asked they about your resistors .
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@thieliste
I replaced the speaker posts on my 2.7's with Cardas CCGR posts ,
a bit of work drilling the holes , the originals use a rectangular hole .
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I posted an image of my upgrade 2.7 woofer board , tag = Thiel scrolled down almost the last system .
I'd say that I am hearing a more forceful and/or quicker low end , one that doesn't weaken or roll off as it goes lower .
A lot of work and this was the easy board to work on !
Also the screws holding the boards contained iron , replaced with brass .
@pieper1973
Sorry to hear about your mishap , are you going to repair or replace ?
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Funny side note
I was looking at HiFi equipment sales in Portland Oregon
and at Fred's sound of music they still have Thiel Audio
listed under New Components !
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@big_greg
You have a lot more experience with equipment than I will ever have , but your thoughts about the phono stage is something I can totally agree with . Does your Sota have the vacuum hold down ?
My experience is with MM cartridges only using a phono stage that is 100% tube for MM's is that a world of difference can be had with changing just one tube or with matching the one 12au7 with different sets of 3 x 5751's .
Also the setting up of a cartridge an art in itself ! Something that I am continually learning to improve my skill at .
I should be receiving my ESRE capacitors soon and will be upgrading the coaxial boards resistors and capacitors next week , except the 1uf bypass caps that will have to wait until the Clarity PUR's are available . I hope the mids and highs sound as good as the lows have sounded since upgrading the woofer boards .
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bobscliff check out speakerworks they have a good video on repairing speakers .
big_greg. I have a Merrill Heirloom TT with an outer clamping ring and I think it makes a big difference , I am surprised that there aren't more TTs with either an outer ring or vacuum hold down .
As for your 3.6s. have you thought of rebuilding/upgrading your crossovers ?
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@dmac67
CS3.6 speakers are a good choice and a bargain at that price but I would be asking Tom his opinion about the fact that the tweeters and midrange speakers were replaced before you buy .
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Thanks
Until you finish your upgrade project , then you'll have the best bar none .
I hope it looks as good as improvedsounds does .
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" Blue Printed "
As a DIYer I can tell you that it is impossible for me to "blue print " my crossover boards , but I can and have been able to " balance " them . To truly blue print a board one must have a box full of each component in order to find components that are the exact values as the schematics , this is what Jim did when he personally checked, measured and approved review samples .
But " balanced " is something that I believe that every Thiel speaker from Lexington is , that is that a 2 ohm resistor might measure 2.1 ohms so finding another one for the other board you'll be balanced same goes for a capacitors values , as long as all the values are within a tolerance set by Thiels quality control .
I'm bring this up because after removing the resistors and capacitors I measured them and discovered resistors that were more than 5% tolerance and electrolytic capacitors that up to 30% out of tolerance ! But since My speakers came from Tennessee and had been put together or repaired there I won't say that this is typical but I was surprised to have measured such differences in the resistors that are used in all Thiel speakers and very disappointed in the electrolytic caps that I took out and then have the same issue with the new replacements ! I purchased a different manufacturer and received caps that were closer to being within tolerance at least they were the same values , So while none of the new components were exact schematic values they were almost exact match pairs thus balanced L & R crossovers .
DIYing is not something that is easy but in my case it turned out to be extremely rewarding because now with upgraded components I know these sound better than stock as well as fixing the FrankenThiel lack of quality crossovers that " New Thiel Audio " sold me .
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Thank You Tom
There is no need to defend Thiel , I purchased these speakers based on the extremely positive reviews and the overwhelming enthusiastic support from individual owners .
I can say that when New Thiel was bankrupt and selling off stock that they put 9 CS2.7 pairs for sale on e-Bay , along with 6 or 9 CS1.7's and the one I wish I could have afforded a CS3.7 that I was told that they had it as a museum piece . Based on my experience I tend to believe that the speakers sold on e-Bay were probably thrown together from parts laying around by an non-technician since one of the resistors was the totally wrong value. I got a bargain , the only way I could have afforded a new pair of Thiel speakers ( even with all the issues I discovered ) Luckily I was able to correct and still at the same time upgrade for a lot less than even the price used speakers at that time but unfortunately there are a few pairs out there that might not live up to Thiel standards .
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