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Ever heard of Jamo 707 speakers?
- Thread starter ta131js
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ta131js
Super Member
I know they are made in Denmark - original home of Dynaco right?
I'm curious because a pair appeared on a local Craigs List last night - and according to the seller he has received 3 calls already. Limited info on the internet - mostly in German/Czech/Danish - when translated don't make much sense.
I'm curious because a pair appeared on a local Craigs List last night - and according to the seller he has received 3 calls already. Limited info on the internet - mostly in German/Czech/Danish - when translated don't make much sense.
Rolf Zetterberg
Well-Known Member
There seem to be a 707 and a later A707(what do they think of?).Picture of the early 707 from the early 90's:
http://my.hifi.nl/index.php?user=720
http://my.hifi.nl/index.php?user=720
michigannick
Well-Known Member
dredging up a su per old thread as I just picked a pair of these up, in the family we have their little brothers, the 507s same design just smaller, the 507's were decent enough but for sure not going to supplant the ADS L1590s in the room with them, but when looking at the quality of drivers and enjoying the beautiful design and design concept i thought these should sound a bit better, and the reviews were largely pretty good on this (excepting this thread so far) so i thought id ask what stood out in your mind to stamp the crap lable on them? with 507s had similar to the review on the 707s a bit of a whole in the mid-range, switching out for quality film caps (decent like daytons or erse i forget, but not higher end) and while in there changing the resistors to 2% ... the speakers really came alive the hole in the mid-range went away completely imaging jumped into a new realm ... not one to care about an effort and perfectly happy to re cap something and say .. "well .. that was a waste" (meaning i am not the type to be married to a speaker cause an hour of effort went into them) This ranks as one of the best transformation recaps on anything that was "modernesque" So having had such good success with the smaller 507's when i saw these pop up cheap and looking pretty i jumped.. now y'all have me in fear :-D
michigannick
Well-Known Member
To clarify I am thinking items looking like this of the following style, they have to be placed correctly to get bass out of them but the recap and resistor work did wonders, and the woofers need to be wired one in, one out of phase there has been some indications of that not being the case which will make the bass anemic quite quick.
michigannick
Well-Known Member
if you meant the A 707 thin aluminum things i cant imagine every considering them without a subwoofer, i cant speak to the actual sound though
Pelleplutt
New Member
Thanks alot michiganick for this post!
I've had these speakers since mid 90's when I suffered from hifi flue. Drove them with Electrocompaniet AW100 and I was more than satisfied. Today I've recovered from the flue but they are still good enough for my needs.
What I want to ask you is this:
- What caps and resistors (brand?) did you change crossover with?
- Woofer wirings, did you switch connectors on the push-pull woofers inside the cabinet?
I was an electronic engineer by profession but soldering is not my cup of tea, I know people who can do this in a professional way.
Thanks again, warm greetings from Sweden!
michigannick
Well-Known Member
Sorry, it's been so long here but I did find improvements in the transition mid to high to improve a good amount, I believe I found a schematic at some point that allowed me to validate the push-pull proper order for the woofers I think the top woofer facing down was in phase bottom inverted, but that is just from memory.
The caps and resistors I swapped for were audio resistors sand cast from Parts Express and Dayton film caps. They were nothing fancy but Dayton or ERSE Audio poly film caps +-1, 2 or at most 5% but i likely target the 1%/2% goal to dial in the system as close to what I hoped the engineers had specified and the tight tolerance to make sure left and right matched/balanced as best as I could .. these are decent quality caps and not expensive, same with the resistors, and not expensive all in parts was a meal as a low to middle priced restaurant for one person.
Side note i don't have the details anymore but i do know with my limited test equipment i was able to see there was a fair amount of variation in the components and if memory serves, at least one component was out of spec which i belive were all Plus Minus 10% products
michigannick
Well-Known Member
thanks for giving this a bump I missed this some time ago, I didn't have particularly useful information but the approach is useful maybe,
I accidentally ended up a mint pair of 507A. They are VERY nice looking, and sound pretty good, tho a bit warm sounding, the upper transients seem muted. I think its definitely worth a few caps and resistors to see what they are capable of. Does anybody have a schematic?
